Murray cod-rhizoma acori graminei circulating water fish-medicine symbiotic culture system and culture method

Abstract

The invention relates to the technical field of agricultural production, and particularly discloses a circulating water fish and medicine symbiotic culture system and method for Murray cods and acorus gramineus, a sunlight type greenhouse is built, and a culture area, a planting area and a backflow area are planned in the greenhouse; a plurality of culture ponds are built in the culture area, and an adjustable sunshade is built above the culture area through a sunshade net; a plurality of hydroponic planting beds are built in the planting area; a plurality of backflow wells are built in the backflow area, and volcanic rock layers, quartz sand layers and biological ball layers are sequentially laid in the backflow wells from bottom to top; rhizoma acori graminei seedlings are selected and buried into the hydroponic planting bed, water is injected to submerge the roots of the rhizoma acori graminei After the rhizoma acori graminei seedlings grow for a period of time, part of leaves are cut off, and humic acid and monopotassium phosphate are sprayed; and selecting Murray gadus fries and putting the fries into the culture pond for culture. The method has the characteristics that the construction cost of the recirculating aquaculture mode of the Murray cods and the rhizoma acori graminei can be reduced, and the comprehensive economic benefit can be improved.

Description

Technical Field

[0001] This invention relates to the field of agricultural production technology, and in particular to a recirculating aquaculture system and method for the breeding of Murray cod and calamus fish. Background Technology

[0002] Murray cod, with its tender flesh and few bones, is a high-end edible fish, hailed as a "national treasure fish" in Australia. Introduced to my country in 2005, it underwent experimental farming. After years of exploration, recirculating aquaculture systems were determined to be the optimal farming model. Sweet flag (Acorus gramineus) has a well-developed root system that effectively absorbs ammonia nitrogen, nitrite, and phosphate in the water, reducing pollution from fish excrement and maintaining ecological balance. Furthermore, the allelochemicals secreted by its roots can inhibit excessive algae growth, reducing the risk of eutrophication. The roots also form pores in the substrate, increasing... Increasing dissolved oxygen levels and microbial attachment area in the water accelerates the conversion of ammonia nitrogen to nitrates, providing nutrients for plants. The roots can be used medicinally, and their value increases with age. Compared to other suitable aquaponics plants, *Acorus calamus* is evergreen and maintains its purification capabilities even in winter, solving the problem of different planting and cultivation periods for commercial fish farming and economic plant cultivation. Patent document CN109463324A discloses a Murray cod recirculating aquaculture system and a Murray cod cultivation method, including cultivation... The invention relates to a pond and a water circulation system, with the aquaculture pond and water circulation system connected in a closed loop. The water circulation system includes a filtration device, a biological tank, a purification tank, and an aeration mechanism. Water discharged from the aquaculture pond passes through the filtration device, biological tank, and purification tank sequentially before flowing back into the aquaculture pond. The filtration device filters suspended solids in the water. The biological tank cultivates bacteria to consume and decompose waste in the water. The purification tank removes harmful substances and bacteria from the water using ozone and ultraviolet light. The aeration mechanism increases the oxygen content in the water. The Murray cod aquaculture method provided by the invention utilizes the aforementioned Murray cod recirculating aquaculture system. The Murray cod recirculating aquaculture system of the invention can improve water resource utilization and reduce energy consumption and emissions. The Murray cod aquaculture method of the invention can improve the growth rate of Murray cod. However, the investment in aquaculture facilities and equipment is relatively high. Existing technologies provide simple and universal aquaponics solutions, but Murray cod prefer high dissolved oxygen levels and have high water quality requirements, which differs from other fish species. Therefore, existing technologies suffer from high costs and low input-output ratios when cultivating Murray cod. Summary of the Invention

[0003] To address the problems of high requirements and large investment in production facilities, as well as high water purification and operating costs in existing technologies, this invention provides a Murray cod-Acorus calamus recirculating aquaculture system and method, thereby reducing the construction cost of the Murray cod-Acorus calamus recirculating aquaculture model and improving overall economic benefits.

[0004] The first technical solution of this invention: a recirculating aquaculture system for Murray cod and Acorus gramineus, comprising the following steps: (S01) constructing a solar-type greenhouse, and planning a breeding area, a planting area, and a recirculation area within the greenhouse; creating a controllable artificial environment; the greenhouse can effectively resist extreme weather such as rainstorms, strong winds, and cold waves, maintaining a relatively stable temperature inside the greenhouse, which is crucial for both Murray cod and Acorus gramineus; dividing the system into three functionally distinct areas, achieving physical separation and functional coupling, facilitating management and operation, and avoiding mutual interference; improving the stability and production efficiency of the system, and reducing the impact of sudden environmental changes. This mitigates the risks and lays the foundation for refined farming and planting; (S02) Several farming ponds are built within the farming area of ​​step (S01), and adjustable shade nets are used to build an adjustable shade canopy above the farming area to avoid direct sunlight and excessive local temperature, thus providing a good growth environment for Murray cod; separate farming in ponds facilitates batch and size farming, realizes "all in, all out" management, reduces the risk of cross-infection of diseases, and also facilitates feeding and harvesting; shading and light control are crucial because Murray cod prefers shade, and strong light will cause stress, affecting growth and health. The adjustable shade canopy can precisely control light intensity and temperature, significantly improving the survival rate of Murray cod and Growth rate, improve fish meat quality, reduce fish stress and disease incidence; (S03) Construct several hydroponic planting beds in the planting area of ​​step (S01), the hydroponic planting beds are equipped with water inlets and overflow outlets, the height of the water inlets is lower than that of the overflow outlets; provide a growth platform for sweet flag and realize hydraulic circulation; hydroponic planting, so that the roots of sweet flag are completely immersed in nutrient-rich water, efficiently absorbing substances such as ammonia nitrogen and nitrates; water level control, the design of low water inlets and high overflow outlets ensures that the planting beds can maintain a constant water level, which will not submerge the base of the plants and cause rot, and will allow all roots to come into contact with the water flow, while the overflow outlets are also controlled. The inlet ensures the continuity of water flow, allowing the treated water to flow smoothly into the next stage; it improves the efficiency of plant absorption of purified water while ensuring smooth water flow, thus achieving water purification for the entire system; (S04) Several return wells are built in the return zone of step (S01), and volcanic rock layer, quartz sand layer and biosphere layer are laid in the return wells from bottom to top, and water is injected into the return wells; it is the "kidney" and "engine" of the entire system, performing biological filtration and water pump return; the volcanic rock layer can provide a huge specific surface area for attaching nitrifying bacteria and other microorganisms, and is the core of water purification, responsible for removing the highly toxic ammonia nitrogen NH3 / NH4 produced by fish feces. + It is converted into less toxic nitrite NO2. - It is then converted into almost non-toxic nitrate NO3. - nitrate NO3 -It is a good fertilizer for sweet flag; the quartz sand layer mainly plays a physical filtration role, intercepting suspended particles, uneaten food, feces and other solid waste in the water, preventing blockage of subsequent pipes and biological filter media; the biosphere layer also provides a surface for biological attachment, and its structure can increase the water flow path, increase dissolved oxygen, and further promote nitrification; the return well integrates filtration, aeration, water storage and water pump, and the treated clean water is pumped back to the breeding pond to complete the cycle; it thoroughly degrades the toxicity of fish excrement and keeps the water clear and oxygen-rich, which is the key to the high-density breeding and survival of fish; (S05) Select sweet flag seedlings and bury them in the hydroponic planting bed of step (S03), and fill the water to submerge the roots of the sweet flag seedlings. Spraying with naphthaleneacetic acid (NAA) promotes rapid rooting and establishment of Acorus gramineus. NAA is a synthetic auxin that strongly stimulates plant cell division and expansion, induces root formation, and promotes root development. It shortens the seedling establishment period of Acorus gramineus, allowing it to adapt to the aquatic environment more quickly and perform its water purification function. The continuously submerged water environment satisfies the moisture-loving characteristics of Acorus gramineus, ensuring its healthy growth and thus strengthening its ability to absorb and purify nitrogen and phosphorus in aquaculture water, creating a clean water environment for Murray cod. (S06) After the Acorus gramineus seedlings in step (S05) have grown for a period of time, some leaves are cut off and humic acid and potassium dihydrogen phosphate are sprayed. This maintains the continuous growth and function of Acorus gramineus. Pruning the leaves simulates harvesting and avoids excessive plant growth. Squeezing promotes new leaf growth and maintains high physiological activity; spraying humic acid, an organic acid, improves plant metabolism, enhances the absorption of trace elements, and strengthens resistance; spraying potassium dihydrogen phosphate provides phosphorus and potassium, with phosphorus promoting root development and potassium enhancing disease resistance and photosynthetic efficiency. Although fish manure provides nitrogen and some phosphorus and potassium, foliar application ensures balanced nutrition; maintaining the vigorous growth and strong absorption capacity of the sweet flag ensures continuous and efficient water purification; pruning mature leaves avoids excessive nutrient consumption, while retaining new leaves ensures photosynthetic efficiency and promotes plant rejuvenation; humic acid and potassium dihydrogen phosphate are applied synergistically via foliar spraying to supplement nutrients and... Enhance stress resistance and ensure the healthy growth of Acorus gramineus; continuous leaf renewal and nutrient absorption enhance its purification efficiency of nitrogen and phosphorus in aquaculture water; (S07) after disinfecting the aquaculture pond in step (S02), add water, adjust the pH of the water, supply oxygen to the aquaculture pond, and aerate it; provide a safe environment for the fish fry after "water conditioning"; disinfect and kill pathogens to prevent diseases; Murray cod has specific pH requirements, usually neutral or slightly alkaline, adjusting the pH to a suitable range can prevent stress; aeration and oxygen supply remove residual chlorine in the water, while significantly increasing dissolved oxygen, preparing for the high oxygen consumption of Murray cod and subsequent nitrifying bacteria; create a stable, safe, and oxygen-rich water environment to ensure the survival rate of fish fry after stocking;

[0005] (S08) Select Murray cod fry and put them into the breeding pond of step (S07) for breeding; Murray cod is a cold-water fish species with high economic value. Its excrement serves as the "waste" and nutrient source of the system, driving the entire ecological cycle; breeding precious fish through a recirculating aquaculture system generates the main economic benefits. This invention utilizes microorganisms to transform fish waste into nutrients that plants can absorb, thus achieving an ecological cycle of "raising fish without changing the water and growing vegetables without fertilizing." Murray cod has high economic value, is suitable for high-density recirculating aquaculture, and has a promising market prospect. Sweet flag (Acorus calamus) is not only an aquatic plant but also a traditional Chinese medicine, possessing even higher economic value than ordinary vegetables. Its well-developed root system has strong water purification capabilities, and it is shade-tolerant and adaptable to hydroponics, making it ideal for cultivation in greenhouses alongside shade-loving Murray cod. The entire system of this invention fully adheres to the three core elements of a fish-medicine symbiotic system: fish farming, hydroponics, and microbial nitrification. The zoning design and multi-layered filter structure of the return well demonstrate professional expertise. Considering the shade-loving nature of Murray cod, this invention features a specially designed adjustable shade structure, reflecting a deep understanding and respect for the physiological habits of the cultured organisms. The use of naphthaleneacetic acid (NAA) for root promotion, humic acid, and potassium dihydrogen phosphate foliar fertilizer supplements marks a step into the realm of refined agricultural management, aiming to maximize plant output and efficiency.

[0006] Preferably, in step (S01), the area of ​​the planting area is larger than the area of ​​the breeding area.

[0007] Preferably, in step (S01), the ground level of the aquaculture area is higher than that of the planting area; the ground level of the planting area is higher than that of the return flow area. This stepped height difference (aquaculture area > planting area > return flow area) utilizes the water level difference to achieve fully automatic, non-powered water circulation; it saves energy and reduces consumption, as water flows by gravity from the highest aquaculture area to the planting area, and then to the lowest return flow well. After treatment in the return flow well, only one pump is needed to pump the water back from the lowest point to the highest aquaculture pond, saving a significant amount of energy compared to repeatedly pumping water between different levels; the process is smooth, as the natural water flow created by the height difference ensures unobstructed water circulation, conforming to the natural law of "water flowing downhill," reducing the risk of pipe blockage; it significantly reduces the system's operating electricity costs, simplifies pipe design, and improves the system's reliability and automation. By utilizing the moderate elevation difference between the aquaculture area and the planting area, nitrogen- and phosphorus-rich aquaculture water naturally flows into the planting area and is absorbed and purified by the roots of Acorus calamus. The elevation difference between the planting area and the return flow area promotes the gravity flow of water from the aquaculture area into the planting area, reducing the energy consumption of circulation. The layered layout creates a micro-flow and quiet environment for Murray cod, which not only meets its preference for slow flow but also maintains water quality stability through water circulation, while providing a continuous supply of water and fertilizer for the cultivation of Acorus calamus.

[0008] Preferably, the height of the greenhouse in step (S01) is 4m to 6m. More preferably, the height of the greenhouse in step (S01) is 4.5m to 5.5m. Even more preferably, the height of the greenhouse in step (S01) is 5m.

[0009] Preferably, the dome of the solar greenhouse in step (S01) is arc-shaped. This optimizes the internal environment of the greenhouse; provides a large buffer space, and the higher ceiling facilitates the rising and accumulation of hot air in summer, which is then exhausted through the roof windows, preventing excessively high temperatures inside the greenhouse. In winter, the larger air volume results in slower temperature changes and better stability; ensures uniform lighting, as the arc-shaped dome is more conducive to even light distribution than a pointed or flat roof, reducing the shaded area and allowing the sweet flag in the planting area to receive more even light and grow more uniformly; provides a stable structure, as the arc-shaped structure has good mechanical properties and can effectively resist wind and snow loads; and creates a more stable and suitable "microclimate" for plant and animal growth, reducing stress responses caused by sudden temperature changes.

[0010] Preferably, in step (S01), the outer surface of the dome of the solar greenhouse is covered with insulating material. This enables active temperature control, especially for winter insulation; it also provides nighttime insulation, as sunlight warms the greenhouse during the day by passing through the film / glass, and the insulating material, like a blanket, greatly reduces heat loss at night, effectively preventing excessively low nighttime temperatures in winter, which is crucial for Murray cod, which prefers cool conditions but is not resistant to severe cold; it offers flexibility, as the "movable covering" means it can be opened and closed at any time according to weather conditions, allowing for full sunlight exposure on sunny days and insulation on cloudy, snowy days or at night; it significantly expands the system's production capacity throughout the year, especially during cold seasons, enabling off-season farming and planting, thus doubling economic benefits.

[0011] Preferably, the area ratio of the planting area to the aquaculture area in step (S01) is 3-4:1. More preferably, the area ratio of the planting area to the aquaculture area in step (S01) is 3.5:1. A planting area greater than the aquaculture area ensures the system's nutritional balance and water purification capacity; the purification capacity is matched, as fish waste, mainly ammonia nitrogen, is enormous, and a sufficiently large planting area means there are enough *Acorus calamus* roots and microorganisms to absorb and transform this waste, preventing nitrate accumulation in the system and thus maintaining water quality stability; economic benefits are maximized, as *Acorus calamus*, as a traditional Chinese medicine, may have an economic value no less than or even exceeding that of Murray cod, and expanding the planting area directly increases the overall economic output per unit area; the system is more stable, the water purification capacity is more guaranteed, and the total output value and profit per unit of land are higher.

[0012] Preferably, in step (S01), the ground level of the breeding area is 1m to 2m higher than that of the planting area. More preferably, in step (S01), the ground level of the breeding area is 1.5m higher than that of the planting area.

[0013] Preferably, in step (S01), the ground level of the planting area is 0.3m to 1m higher than the ground level of the recirculation area. More preferably, in step (S01), the ground level of the planting area is 0.4m to 0.9m higher than the ground level of the recirculation area. More preferably, in step (S01), the ground level of the planting area is 0.5m to 0.8m higher than the ground level of the recirculation area. More preferably, in step (S01), the ground level of the planting area is 0.6m to 0.7m higher than the ground level of the recirculation area. A precise balance between hydraulic performance and engineering costs is achieved; flow velocity and scouring are ensured; a limited height difference ensures sufficient potential energy for water flowing out of the aquaculture pond, creating a certain flow velocity as it flows into the planting bed, which helps carry away solid waste and prevents sedimentation in pipes and the planting bed; a limited height difference between the planting area and the return flow area ensures sufficient depth for the return flow well to accommodate multiple layers of filter media—volcanic rock, quartz sand, and bio-balls—and to install water pumps, while also ensuring sufficient immersion depth for the pumps to prevent dry running; construction costs are controlled, as excessive height differences increase earthwork and building structure costs. These optimal values ​​are calculated to be economically reasonable while meeting hydraulic requirements; the system achieves the highest water circulation efficiency while optimizing construction and maintenance costs.

[0014] Highly aligned with ecological principles and engineering mechanics, the design perfectly utilizes physical principles such as gravity and thermodynamics, combined with the ecological cycle principle of fish-medicine symbiosis, resulting in a highly scientific design. Its exceptional economic efficiency and practicality are evident in the gravity flow design, which directly determines the system's competitive operating costs. The quantification of area ratio and height difference reflects a deep understanding moving from "theoretically feasible" to "economically optimal," representing the culmination of extensive calculations and practical experience. Comprehensive and meticulous environmental control measures—height, dome, and insulation—ensure that the main products, Murray cod and sweet flag, can grow in the best environment, guaranteeing both yield and quality. The design demonstrates systematic thinking, considering not only biological needs but also energy consumption, construction costs, operational convenience, and environmental adaptability.

[0015] Preferably, in step (S02), the depth of the aquaculture pond is 1.5m to 2.0m, and the area of ​​the aquaculture pond is 15m². 2 ~20m 2 More preferably, in step (S02), the depth of the aquaculture pond is 1.6m to 1.8m, and the area of ​​the aquaculture pond is 16m². 2 ~18m 2 More preferably, in step (S02), the depth of the aquaculture pond is 1.7m and the area of ​​the aquaculture pond is 17m². 2This design creates an optimal growth environment for Murray cod and enables efficient management. Water stability is crucial; the defined depth range forms a large "buffer" with ample water volume. This larger volume prevents sudden temperature fluctuations due to short-term air temperature changes (e.g., heating during the day and cooling at night), and water quality indicators such as pH and ammonia nitrogen are more stable. Regarding fish behavior, Murray cod are bottom-dwelling fish and require sufficient water depth to support their vertical movement. Shallow water can cause stress, while excessively deep water may lead to insufficient dissolved oxygen at the bottom and waste construction costs. The defined depth range effectively balances their needs, maintains dissolved oxygen at the bottom, and controls water quality. The optimal balance between cost and efficiency is achieved through a defined pond area that ensures sufficient volume for economic benefits while facilitating manual management such as fish observation, feeding, harvesting, and pond cleaning. Excessive pond size increases management difficulty and risk. Precise density calculations (unit: kg fish / m³ water) are also crucial. A stable aquatic environment significantly reduces fish stress, lowers disease incidence, and improves feed conversion rates, ultimately resulting in higher yields and better economic benefits. The deeper ponds and spacious areas meet the growth and activity needs of Murray cod.

[0016] Preferably, the shading rate of the sunshade in step (S02) is 50% to 60%. More preferably, the shading rate of the sunshade in step (S02) is 55%. Precisely mimicking the original habitat of Murray cod, using shady, clear streams or lakes, and controlling light intensity reduces stress. Murray cod dislike strong light; excessive light causes restlessness, inactivity, and cessation of feeding, severely impacting growth. Limited shading creates a gentle, cool environment, making them feel safe and allowing for normal behavior. It also controls algae growth; excessive sunlight promotes the overgrowth of phytoplankton, primarily green algae, in the aquaculture pond. Algae cause drastic diurnal pH fluctuations—rising pH during the day due to CO2 absorption and falling at night due to CO2 release—and competes with fish for dissolved oxygen, increasing management difficulty. Limited shading effectively inhibits excessive algae growth, maintaining clear and stable water quality. Furthermore, it regulates water temperature by partially blocking direct sunlight, preventing excessively high water temperatures in summer and maintaining them within the optimal growth range for Murray cod. This results in normal behavior, robust growth, clear water, active feeding, uniform growth, and avoidance of water quality deterioration risks caused by algae problems. Shade canopies regulate light intensity to a low-light environment, which can prevent direct sunlight from causing excessively high water temperatures in summer, reduce fish stress, and inhibit excessive algae growth; shade canopies also regulate light intensity to meet the shade-loving characteristics of Acorus calamus.

[0017] Preferably, the shading rate of the sunshade in step (S02) is calculated as follows:

[0018] In the formula, natural light intensity refers to the light intensity measured outside the shade net using a light intensity meter; light intensity inside the net refers to the light intensity measured inside the shade net using a light intensity meter. This provides an objective, quantifiable, and reproducible standard for defining and measuring "shading rate"; it eliminates ambiguity, avoiding vague descriptions such as "good shading effect" or "semi-shading," providing clear data for procurement, installation, and acceptance; it ensures consistent results, verifying the shading effect of any shade net manufacturer or material to meet system requirements, thus guaranteeing consistent environmental conditions in each aquaculture pond; it is scientifically sound, as this formula is a standard method for defining shading / transmittance in optics and materials science, ensuring scientific rigor; and it achieves standardized and precise environmental control, a core characteristic of modern, industrialized agricultural production, ensuring the predictability and stability of production results. Highly aligned with the species' habits, all parameters—water depth, area, and lighting—are meticulously designed to meet the physiological and behavioral needs of Murray cod, with the design entirely centered on the "fish." It embodies the essence of data-driven management, abandoning vague notions of "approximately" or "close enough" and providing precise numerical ranges. This data-driven approach significantly enhances the operability and replicability of the solution. It balances biological needs with economic benefits; the pond's size design considers fish welfare, ease of artificial management, and land utilization, finding a "sweet spot" that maximizes economic benefits. The design is rigorously scientific, providing a specific formula for calculating shading rate, demonstrating the designer's high level of professionalism and meticulousness, ensuring that technical standards are not distorted during transmission and implementation.

[0019] Preferably, in step (S03), the height of the hydroponic planting bed is 40cm to 50cm, and the area of ​​the hydroponic planting bed is 10m². 2 ~21m 2 More preferably, in step (S03), the height of the hydroponic planting bed is 42cm to 48cm, and the area of ​​the hydroponic planting bed is 15m². 2 ~20m 2 More preferably, in step (S03), the height of the hydroponic planting bed is 45cm, and the area of ​​the hydroponic planting bed is 18m². 2 To create optimal growth space for the roots of *Acorus gramineus* and match it with the system scale; the root space, with a defined depth, provides ample room for the extensive underground creeping rhizomes and fibrous roots of *Acorus gramineus* to extend, avoiding overcrowding and ensuring maximum absorption of water and nutrients; the water buffer, similar to the aquaculture pond, a certain depth of water and substrate layer can act as a buffer zone for water quality, stabilizing the temperature and hydrochemical environment of the planting area; the area matching, the defined area is the result of matching with the previously determined aquaculture area scale, water flow rate and nutrient load, ensuring sufficient plants to purify the water from the aquaculture pond; *Acorus gramineus* grows vigorously, has a large biomass, high water purification efficiency, and stable yield per unit area.

[0020] Preferably, in step (S03), the diameter of the inlet is φ20mm to 40mm, and the diameter of the overflow outlet is φ20mm to 40mm. More preferably, in step (S03), the diameter of the inlet is φ25mm to 35mm, and the diameter of the overflow outlet is φ25mm to 35mm. Even more preferably, in step (S03), the diameter of the inlet is φ30mm, and the diameter of the overflow outlet is φ30mm. Precise control of flow rate and volume; flow balance, the limited diameter is the result of hydraulic calculations, it needs to ensure that the inflow of water meets the needs of the plants and forms a certain water flow path, but does not wash away the roots or cause water to overflow from the bed surface due to excessive flow rate. At the same time, it must be able to drain water in time to maintain balance with the inflow flow and maintain the set water level; anti-clogging, a sufficiently large diameter can effectively prevent blockage caused by the roots or debris of sweet flag, reducing maintenance needs; stable water level in the planting bed, smooth water flow, and minimal management and maintenance workload.

[0021] Preferably, in step (S03), the inlet and outlet are arranged diagonally on the hydroponic planting bed. This achieves uniform water distribution within the planting bed; reduces stagnant water areas; and the diagonal layout creates the longest water flow path, forcing water flowing in from one corner to flow through almost the entire bed before exiting from the opposite corner. This ensures that the water flow diffuses throughout the entire area, preventing water from flowing directly to the outlet via a short circuit, thus ensuring that the roots in every corner of the bed can come into contact with fresh, nutrient-rich water. It also improves efficiency, maximizing the purification capacity of the entire planting bed and avoiding local overload or ineffectiveness. Plants grow uniformly, and the water purification effect is maximized, with no dead zones.

[0022] Preferably, in step (S03), the height of the inlet is 3cm to 8cm lower than the overflow outlet. More preferably, in step (S03), the height of the inlet is 4cm to 7cm lower than the overflow outlet. Even more preferably, in step (S03), the height of the inlet is 5cm to 6cm lower than the overflow outlet. This method maintains a constant root submersion depth; automatic water level control with an "overflow weir" design ensures that excess water automatically flows out once the water level reaches the overflow outlet height, and the inlet position does not affect the water level, which is always determined by the overflow outlet height; it protects the plant by ensuring the water level is always below the base of the *Acorus gramineus* seedlings, preventing long-term soaking and rotting; it ensures root contact, and the limited water depth ensures that most of the *Acorus gramineus* roots are submerged, allowing for full absorption of nutrients and water, while the substrate surface remains slightly dry, promoting aeration and preventing anaerobic environments; it automatically maintains the optimal water level without human intervention, keeping the roots in an optimal state of "water-air balance."

[0023] Preferably, a layer of expanded clay pebbles is laid in the hydroponic planting bed in step (S03). The expanded clay pebbles substrate has both air permeability and water retention, and the slope design ensures balanced root respiration and water supply.

[0024] Preferably, the ceramsite in the ceramsite layer is prepared by soaking and disinfecting coarse ceramsite with a particle size of 10-20 mm in a sodium hypochlorite solution with a concentration of 20-50 ppm, followed by rinsing. More preferably, coarse ceramsite with a particle size of 12-18 mm is soaked and disinfected in a sodium hypochlorite solution with a concentration of 25-45 ppm. Even more preferably, coarse ceramsite with a particle size of 14-16 mm is soaked and disinfected in a sodium hypochlorite solution with a concentration of 30-40 ppm. Even more preferably, coarse ceramsite with a particle size of 15 mm is soaked and disinfected in a sodium hypochlorite solution with a concentration of 35 ppm. This product provides an ideal "three-in-one" substrate for plant fixation, microbial attachment, and physical filtration. For plant fixation, the moderate weight of the expanded clay pebbles effectively anchors Acorus gramineus seedlings, preventing them from lodging or floating. For microbial attachment, the rough, porous surface of the expanded clay pebbles provides a large surface area for nitrifying bacteria and other beneficial microorganisms to attach, forming a "biofilm"—the second most important water purification site after the return well. Physical filtration traps fine suspended solids carried in the water flow, further purifying the water. The porous structure between the expanded clay pebbles ensures oxygen supply to the root zone, preventing root rot, while also absorbing and retaining moisture. Strict disinfection is achieved through soaking in a specific concentration of sodium hypochlorite, a safe and easily decomposable disinfectant that kills pathogens, insect eggs, and weed seeds that may be present in the expanded clay pebbles, eliminating the risk of introducing systemic contamination. The precise concentration ensures effective disinfection without residual toxicity. Plants take root firmly and have healthy root systems. Microbial activity is high. Water undergoes secondary purification, preventing disease at its source. Disinfection treatment effectively kills harmful microorganisms in the substrate, reducing the risk of disease.

[0025] Preferably, the thickness of the expanded clay layer in step (S03) is 20cm to 30cm. More preferably, the thickness of the expanded clay layer in step (S03) is 22cm to 28cm. Even more preferably, the thickness of the expanded clay layer in step (S03) is 25cm. This achieves an optimal balance between cost, function, and weight; sufficient root growth, with the limited thickness fully meeting the growth needs of the Acorus gramineus root system; sufficient microbial colonization, providing ample substrate for microorganisms to attach and perform biological filtration; controlled total weight, as an excessively thick substrate layer would significantly increase the overall weight of the planting bed, placing higher demands on the load-bearing capacity of the bed structure and greenhouse floor; and optimized construction costs and structural safety while ensuring optimal function. The systemic approach ensures that each parameter is not isolated but closely linked to the size of the aquaculture pond, the water pump flow rate, and the plant's needs, reflecting true systemic design. Precise environmental control, through precise control of influent / outfluent, water level, and substrate, creates a near-ideal chemical, bio, and physical environment for plants and microorganisms. Automated and maintenance-free design, including overflow weir-style water level control, anti-clogging orifice design, and diagonal water distribution, significantly reduces the need for daily manual intervention in the planting bed, lowering long-term operating costs. Proactive risk prevention, with its rigorous disinfection of the expanded clay pellets, is a forward-thinking and excellent practice that eliminates many potential plant diseases and systemic contamination risks before they emerge, avoiding substantial subsequent treatment and management costs. Quantification and replicability ensure that all details are quantified, allowing the solution to be perfectly replicated from a successful pilot site to any other location, guaranteeing consistent results.

[0026] Preferably, in step (S04), the depth of the reflux well is 1m to 2m, and the volume of the reflux well is 40m³. 3 ~60m 3 More preferably, in step (S04), the depth of the reflux well is 1.2m to 1.8m, and the volume of the reflux well is 45m³. 3 ~55m 3 More preferably, in step (S04), the depth of the reflux well is 1.5m, and the volume of the reflux well is 50m³. 3It provides ample space for biological reaction and water buffer capacity; sufficient volume and depth to accommodate filter media (as mentioned below), and sufficient immersion depth for the water pump; hydraulic retention time, the limited volume ensures sufficient retention time of wastewater in the return well, allowing nitrifying bacteria ample time to convert toxic ammonia nitrogen and nitrite into nitrate; too small a volume will lead to incomplete treatment and large fluctuations in water quality; system stability, the large water volume acts as a "stabilizer," buffering instantaneous changes in water quality caused by feeding, cleaning, and other operations, maintaining extreme stability of the entire system's water quality; strong water purification capacity, high system resistance to shock loads, providing a solid foundation for high-density aquaculture.

[0027] Preferably, in step (S04), the thickness of the volcanic rock layer is 50mm-80mm, the thickness of the quartz sand layer is 20mm-30mm, and the thickness of the biosphere layer is 5mm-10mm. More preferably, in step (S04), the thickness of the volcanic rock layer is 55mm-75mm, the thickness of the quartz sand layer is 22mm-28mm, and the thickness of the biosphere layer is 6mm-9mm. Even more preferably, in step (S04), the thickness of the volcanic rock layer is 60mm-70mm, the thickness of the quartz sand layer is 24mm-26mm, and the thickness of the biosphere layer is 7mm-8mm. Even more preferably, in step (S04), the thickness of the volcanic rock layer is 65mm, the thickness of the quartz sand layer is 25mm, and the thickness of the biosphere layer is 7.5mm. A highly efficient and functionally layered biological filtration unit is constructed. The quartz sand layer is mainly responsible for physical filtration. Its fine particle structure effectively traps fine suspended solids and organic debris carried in the water flowing out of the planting bed, preventing them from entering and clogging the lower biological filter media. This is the first line of defense for protecting the subsequent biological filter layers. The volcanic rock layer is the core biological filter layer. The porous nature and huge specific surface area of ​​volcanic rock make it an ideal home for the attachment and reproduction of microbial communities such as nitrifying bacteria. Its large thickness ensures that there are enough bacteria to process the large amount of ammonia nitrogen waste produced by fish. The biosphere layer assists in biological filtration and oxygenation. The hollow structure of the biospheres increases the water flow path, promotes gas exchange, and increases dissolved oxygen, providing sufficient oxygen for nitrification. At the same time, it also provides additional surface for biological attachment. The layered structure, with its top-down, fine-to-coarse, and functionally distinct design, conforms to the basic principles of water treatment processes, achieving a perfect combination of efficient physical interception and maximized biodegradation. After physical filtration, the water quality is extremely clear, with ammonia nitrogen and nitrite concentrations maintained at a safe level close to zero, and sufficient dissolved oxygen. The volcanic rock bottom layer intercepts solid impurities and provides a substrate for microbial attachment; the quartz sand middle layer further filters fine particles; and the bio-ball upper layer creates an aerobic environment to promote the reproduction of nitrifying bacteria. The three-stage filter layers work together to achieve efficient conversion of ammonia nitrogen to nitrate. The large return well volume and reasonable filter media ratio extend the water retention time and ensure the water purification effect. This design provides a clean water source for Murray cod farming and an absorbable nitrate nitrogen source for Acorus gramineus growth.

[0028] Preferably, in step (S04), active nitrifying bacteria solution is inoculated into the water of the return well, and oxygen is supplied to the return well for aeration and cultivation, controlling the dissolved oxygen concentration in the water to be 7 mg / L to 10 mg / L. By inoculating with active nitrifying bacteria solution and continuously supplying oxygen, the biological nitrification of the return well is rapidly initiated, converting ammonia nitrogen in the water into harmless nitrate.

[0029] Preferably, in step (S04), the concentration of the active nitrifying bacteria solution inoculated into the water of the return well is 200–300 mL / m³. 3More preferably, the concentration of the inoculated active nitrifying bacteria solution is 220–280 mL / m³. 3 More preferably, the concentration of the inoculated active nitrifying bacteria solution is 240–260 mL / m³. 3 More preferably, the concentration of the inoculated active nitrifying bacteria solution is 250 mL / m³. 3 .

[0030] Preferably, the aeration and cultivation time is 2 to 4 weeks. More preferably, the aeration and cultivation time is 2.5 to 3.5 weeks. Even more preferably, the aeration and cultivation time is 3 weeks. Artificial acceleration of the maturation of the biological filtration system, i.e., "water conditioning" or "bacterial cultivation"; artificial inoculation, where nitrifying bacteria naturally form in an environment that takes 1-2 months, directly inoculating with a high concentration of commercial nitrifying bacteria solution, is like "sowing seeds," which can greatly shorten the system start-up time; precise dosing, with the concentration within a limited range being the recommended value obtained by the bacterial supplier through experiments, can ensure a sufficient number of initial bacteria; high-pressure aeration, as nitrifying bacteria are strict aerobic bacteria with extremely high oxygen requirements, maintaining dissolved oxygen at 7-10 mg / L, far exceeding the requirement of more than 5 mg / L in ordinary aquaculture, creates the best conditions for their reproduction and promotes rapid expansion of the bacterial population; limited cultivation time, providing sufficient generations for the bacterial population to reproduce, allowing it to firmly attach to the filter media and form a biofilm, thus being able to withstand the high ammonia nitrogen load generated after the fish are introduced; the system start-up time is shortened from 1-2 months to 2-4 weeks, and the initial bacterial population is stronger and more stable, greatly reducing the risks during the system start-up phase.

[0031] Preferably, the water quality of the return well is tested every 2 to 4 days during the aeration and cultivation period. More preferably, the water quality of the return well is tested every 3 days during the aeration and cultivation period. The aeration and cultivation process promotes the formation and stabilization of the microbial film, thereby enhancing the system's resistance to shock loads.

[0032] Preferably, in step (S04), the pH value and water temperature of the return well are monitored daily, and the pH value is adjusted to 7.0–7.5. More preferably, the pH value is adjusted to 7.1–7.4. Even more preferably, the pH value is adjusted to 7.2–7.3. This allows for precise monitoring and management of the biological reaction process; monitoring water quality and regularly testing ammonia nitrogen and nitrite levels can accurately determine whether the nitrification system has been successfully established and matured, indicated by the concentrations of ammonia nitrogen and nitrite successively reaching peak values ​​and then dropping to zero; precise pH control is also crucial, as the nitrification process consumes alkalinity (HCO3) in the water. - And produce hydrogen ions H +This leads to a continuous drop in pH value, while the optimal pH range for nitrifying bacteria is 7.2 to 8.0. A pH below 6.0 will severely inhibit or even completely stop nitrification. Monitoring and precisely adjusting the pH to 7.0 to 7.5 daily creates an absolutely ideal working environment for nitrifying bacteria, ensuring they operate at their highest efficiency. Ensuring the rapid and healthy maturation of the biological filtration system and maintaining its highest efficiency throughout operation is the most forward-looking management measure to prevent water quality deterioration. The system achieves ultimate quantification and optimization, providing precise optimized values ​​for every parameter—volume, thickness, concentration, time, and pH—based on extensive theoretical calculations and practical experience, ensuring maximum filtration efficiency. Its scientifically layered functional design separates physical and biological filtration, with different biological filter media working synergistically, perfectly aligning with modern water treatment engineering design principles. Proactive microbial management, through inoculation, aeration, and pH control, actively intervenes in and optimizes the microbial environment, rather than passively waiting. This is a core technology of high-level recirculating aquaculture, significantly improving system reliability and success rate. Risk control is proactive, focusing on the "cultivation" stage before system startup. Meticulous management lays a solid foundation for subsequent aquaculture production, preventing "operation with diseases"—a cost-effective and efficient risk management strategy.

[0033] Preferably, the burying time in step (S05) is from March to May. More preferably, the burying time in step (S05) is from March 5 to April 5. Even more preferably, the burying time in step (S05) is in April. Planting during the optimal phenological period is advantageous; the climate is suitable, April is springtime, temperatures rise and usually stabilize above 15-20℃, sunlight is mild and longer, and humidity is moderate. This is the beginning of the vigorous growth period for most plants after dormancy; seedlings recover quickly and have a high survival rate. Planting at this time allows *Acorus calamus* seedlings to quickly adapt to the new environment, root and sprout rapidly, and are less likely to die from high or low temperature stress; the growth cycle is well-matched, providing the plants with sufficient growth time to establish a strong root system and canopy before the system is put into operation and fish fry are released, thus enabling them to immediately and effectively perform water purification functions; the seedling survival rate is extremely high, with almost no recovery period, and they can quickly enter the growth state, laying a solid foundation for subsequent system operation. Select robust seedlings in spring and plant them densely to ensure that the plants quickly cover the planting bed and form a biological filter barrier.

[0034] Preferably, in step (S05), the seedling height of *Acorus gramineus* is selected to be 10cm-15cm. More preferably, in step (S05), the seedling height of *Acorus gramineus* is selected to be 11cm-14cm. Even more preferably, in step (S05), the seedling height of *Acorus gramineus* is selected to be 12cm-13cm. Selecting seedlings in optimal physiological condition ensures vigorous growth; limiting the seedling height indicates that the seedling has passed its most vulnerable and tender stage, possesses strong photosynthetic capacity and a certain degree of stress resistance, but is still very young, highly malleable, and recovers quickly after transplanting; uniform specifications, selecting seedlings of consistent height facilitates standardized and mechanized operations, and more importantly, ensures consistent plant growth, avoiding competition for light and nutrients between different-sized plants later; uniform plant growth facilitates management and high group purification efficiency.

[0035] Preferably, in step (S05), the distance between adjacent *Acorus calamus* seedlings in the hydroponic planting bed is 8cm to 10cm. More preferably, the distance between adjacent *Acorus calamus* seedlings in step (S05) is 9cm. Determining the optimal planting density maximizes resource utilization; this density is the best balance between the number of plants and the growth space per plant per unit area, maximizing the use of the planting bed area to form an efficient purification barrier while ensuring that each *Acorus calamus* plant has sufficient space to extend its leaves to receive light and for its roots to absorb nutrients. Good ventilation and light penetration are also achieved; the limited spacing ensures good ventilation for the plant canopy and roots, effectively reducing the risk of diseases such as fungal diseases in a humid and enclosed environment. This maximizes the biological yield and water purification efficiency per unit area while maintaining a healthy plant growth environment.

[0036] Preferably, in step (S05), the hydroponic planting bed has several planting holes with a depth of 3cm to 5cm, into which the *Acorus gramineus* seedlings are buried. More preferably, the bed has several planting holes with a depth of 3.5cm to 4.5cm. Even more preferably, the bed has several planting holes with a depth of 4cm. This achieves precise planting; fixes the plant, as the limited depth is sufficient to allow the seedlings to stand stably in the ceramsite, preventing them from falling over due to water flow or their own weight; protects the growth point, as the "heart leaf" growth point of *Acorus gramineus* cannot be buried, otherwise it will rot and die; the limited depth ensures that the roots and base are buried and fixed, while the crucial growth point is exposed to the air; promotes rooting, as the appropriate depth keeps the stem base in a moist ceramsite environment, which is conducive to stimulating the stem to produce adventitious roots and expand the root system; ensures high-quality seedling planting with no damage, safe growth points, and creates optimal conditions for new root development.

[0037] Preferably, the time for spraying naphthaleneacetic acid (NAA) in step (S05) is in the evening. Spraying NAA in the evening maximizes the effectiveness of the plant growth regulator; it prolongs the absorption time, as sunlight weakens, temperatures drop, and transpiration decreases in the evening, preventing the sprayed solution from evaporating too quickly and allowing it to remain moist on the leaves and stems for a longer period, thus enabling longer absorption by the plant; it avoids photodegradation, as many chemicals, including NAA, are easily decomposed under strong light—photodegradation—and evening spraying avoids the loss of efficacy caused by direct sunlight; it synchronizes with the plant's physiological cycle, as plants primarily transport and assimilate nutrients at night, allowing the absorbed auxin to function more efficiently; and at the same dosage, it has a more significant root-promoting effect and higher drug utilization. Spraying NAA in the evening promotes root growth and improves seedling survival rate and stress resistance.

[0038] Preferably, the concentration of naphthaleneacetic acid (NAA) in step (S05) is 50 ppm to 80 ppm. More preferably, the concentration of NAA in step (S05) is 55 ppm to 75 ppm. More preferably, the concentration of NAA in step (S05) is 60 ppm to 70 ppm. More preferably, the concentration of NAA in step (S05) is 65 ppm. This provides the most effective root-promoting stimulation; the optimal stimulation dose, with the growth regulator exhibiting the characteristics of "low concentration promoting, high concentration inhibiting," and the limited concentration range can most effectively stimulate cell division in Acorus gramineus, inducing a large number of adventitious roots to form rapidly, without harming or inhibiting the seedlings; the specific concentration ensures consistent results for each operation, guaranteeing that the standardized seedlings produced have well-developed root systems, dense fibrous roots, and a dramatically enhanced ability to absorb water and nutrients, significantly shortening the recovery period after transplanting. Following the laws of plant growth, all parameters—time, specifications, density, and depth—are completely in accordance with the biological characteristics of Acorus gramineus, embodying the scientific planting philosophy of "adapting to the time and the plant." Quantitative management ensures that every operation has precise quantitative indicators, making the entire planting process fully replicable, verifiable, and controllable. Proactive management utilizes measures such as naphthaleneacetic acid (NAA) not as a remedy after problems arise, but as a "booster" for healthy plant growth and rapid system activation from the very beginning of planting, representing a low-cost, high-efficiency risk investment. System synergy is demonstrated by the perfect matching of planting density, timing, and other parameters with the aforementioned aquaculture pond scale and water flow design, reflecting a strong holistic view of the system.

[0039] Preferably, the growth period of the *Acorus gramineus* seedlings in step (S06) is 3-6 months. More preferably, the growth period of the *Acorus gramineus* seedlings in step (S06) is 4-5 months. This ensures that the *Acorus gramineus* develops strong and stable photosynthetic and purification capabilities before harvesting; the root system is fully developed; a growth period of 3-6 months is sufficient for the underground rhizomes and fibrous root network of the *Acorus gramineus* to fully expand in the expanded clay aggregate substrate, forming a powerful absorption and fixation system; the canopy is fully established; the plant has tillered; the leaves are lush, forming a sufficiently large leaf area index; photosynthetic efficiency reaches its peak; and the water purification capacity is at its strongest. The system is mature; at this time, the plant subsystem, microbial subsystem, and aquaculture subsystem have fully integrated and matured, and the system enters a stable production period. This ensures that at the first harvest, the plant has sufficient roots and remaining leaves to cope with the stress of harvesting and can quickly recover growth, avoiding the risk of plant decline and interruption of water purification function due to premature harvesting.

[0040] Preferably, in step (S06), leaves with a length of 30cm to 40cm are cut. More preferably, in step (S06), leaves with a length of 32cm to 38cm are cut. Even more preferably, in step (S06), leaves with a length of 34cm to 3cm are cut. Standardized harvesting achieves a balance between economic benefits and plant health; sufficient photosynthetic structures are preserved by harvesting only mature leaves from the upper part of the plant, leaving enough leaves from the middle and lower parts to continue photosynthesis, providing energy for the recovery of the plant and its root system, avoiding "killing the goose that lays the golden eggs"; it stimulates the sprouting of new leaves, and appropriate pruning can break apical dominance, stimulating the plant to sprout new tillers and leaves from the base, maintaining the plant's vigorous vitality and youthfulness; it achieves the dual goal of continuously producing economic benefits without harming the plant's healthy ecological functions.

[0041] Preferably, the spraying method in step (S06) is foliar spraying.

[0042] Preferably, the spraying time in step (S06) is in the evening. This provides efficient replenishment of key nutrients; foliar absorption allows humic acid and potassium dihydrogen phosphate to be directly absorbed through leaf stomata and epidermis, resulting in high efficiency and rapid effects, avoiding potential antagonism or fixation effects that may occur with root absorption; precise replenishment allows for targeted and rapid replenishment of specific nutrients such as phosphorus and potassium, compensating for elements that may be relatively deficient in fish manure fertilizer; evening spraying, based on the same principle, avoids photosynthesis and evaporation, prolonging absorption time and improving fertilizer utilization; it quickly corrects potential nutrient imbalances, significantly enhances plant resistance, promotes new leaf germination and root development, and enables plants to recover rapidly after harvest.

[0043] Preferably, the concentration of humic acid in step (S06) is 200 ppm to 300 ppm. More preferably, the concentration of humic acid in step (S06) is 210 ppm to 290 ppm. More preferably, the concentration of humic acid in step (S06) is 220 ppm to 280 ppm. More preferably, the concentration of humic acid in step (S06) is 230 ppm to 270 ppm. More preferably, the concentration of humic acid in step (S06) is 240 ppm to 260 ppm. More preferably, the concentration of humic acid in step (S06) is 250 ppm. Applying biostimulants comprehensively enhances plant physiological functions; promotes nutrient absorption, as humic acid chelates micronutrients, making them easier for plants to absorb, and stimulates cell membrane permeability, improving fertilizer utilization; enhances stress resistance, increasing plant resistance to stresses such as pruning and water temperature changes; improves the microecology, as it can also promote the activity of beneficial microorganisms in the substrate; the concentration is scientifically controlled, with a defined range that is typical, safe, and effective for use as a biostimulant—too low a concentration will have little effect, while too high a concentration may inhibit growth; the plants not only "eat their fill" but also "eat well," resulting in vigorous physiological metabolism and robust growth.

[0044] Preferably, the concentration of potassium dihydrogen phosphate in step (S06) is 0.1% to 0.2%. More preferably, the concentration of potassium dihydrogen phosphate in step (S06) is 0.15%. This method precisely replenishes key macronutrients such as phosphorus and potassium. Phosphorus (P) plays a crucial role in ATP, nucleic acids, and biomembranes; the growth of new organs, leaves, and roots after pruning requires a large amount of phosphorus, and supplementing phosphorus directly promotes wound healing and new tissue formation. Potassium (K) regulates stomatal opening and closing, participates in enzyme activation, and promotes carbohydrate transport and accumulation; supplementing potassium enhances the photosynthetic efficiency of leaves and transports synthesized energy substances to the parts that need growth, while also enhancing disease resistance. The precise concentration, within a defined range, represents a commonly used safe concentration for foliar fertilizers, resulting in significant effects without causing fertilizer damage. It provides direct energy and material support for plant regeneration and recovery, ensuring rapid sprouting of new leaves after harvest and maintaining the system's water purification function. A perfect balance between ecology and economy: "Harvesting leaves" is an act to obtain economic benefits, while "allowing sufficient growth time" and "spraying supplementary nutrients" are measures to maintain ecological functions. The program successfully combines the two, ensuring the long-term sustainability of the system. The management is highly refined, with standard harvesting lengths and nutrient supplementation formulas—humic acid + potassium dihydrogen phosphate, concentrations—250 ppm and 0.15%, timing—after pruning, and method—evening foliar spraying. This is a complete, closed-loop crop nutrient management procedure. Proactive management: not only remedying nutrient deficiencies after they appear in the plants, but also proactively supplementing nutrients after harvesting, the biggest stressor. This is a predictive, preventative management that minimizes system fluctuations. Each measure has a solid plant physiology basis, and the combination of pruning and nutrient supplementation is a standard high-yield technique in horticulture and crop cultivation.

[0045] Preferably, the disinfection time in step (S07) is from March to May. More preferably, the disinfection time in step (S07) is from March to April. Even more preferably, the disinfection time in step (S07) is April. Choosing the optimal time for final preparations before system startup ensures synchronization with the environment, perfectly aligning with the timeline of *Acorus gramineus* planting and microbial cultivation in the return well, guaranteeing that both the plant and microbial systems are ready when the fish fry are released. The climate is suitable; in April, the water and air temperatures are close to the optimal growth range for Murray cod, allowing the water temperature to stabilize within the target range after disinfection and aeration. This enables the simultaneous maturation of the three subsystems—fish, plants, and microorganisms—allowing the system to enter a stable operating state in one smooth process.

[0046] Preferably, in step (S07), a chlorine dioxide solution with a concentration of 1 mg / L to 2 mg / L is used to disinfect the aquaculture pond, followed by rinsing and then filling with water. More preferably, a chlorine dioxide solution with a concentration of 1.2 mg / L to 1.8 mg / L is used to disinfect the aquaculture pond. Even more preferably, a chlorine dioxide solution with a concentration of 1.5 mg / L is used to disinfect the aquaculture pond. This method thoroughly kills pathogens, eliminating source pollution; it is highly efficient and broad-spectrum, as chlorine dioxide is a highly efficient and safe disinfectant with a strong killing effect on bacteria, viruses, fungi, and their spores, and its action is rapid; it is safe, as it has low corrosiveness to equipment at the recommended concentration, and the residue after decomposition is harmless chloride, leaving no residual toxicity after rinsing and having no impact on subsequent fish farming; the concentration is precise, and the limited concentration range is an optimized concentration that ensures thorough disinfection while being absolutely safe and easy to rinse thoroughly; starting from an absolutely "clean" sterile environment, it greatly reduces the risk of future fish diseases. Chlorine dioxide disinfection effectively kills pathogens and reduces the risk of disease occurrence.

[0047] Preferably, the water injection depth in step (S07) is 1.2m to 1.5m. More preferably, the water injection depth in step (S07) is 1.3m to 1.4m.

[0048] Preferably, the water injection rate in step (S07) is 0.2 m / s. 3 / s~0.3m 3 / s. More preferably, the water injection rate in step (S07) is 0.25m / s. 3 / s.

[0049] Preferably, in step (S07), the pH of the water is adjusted to 6.8–7.5. More preferably, in step (S07), the pH of the water is adjusted to 6.9–7.4. Even more preferably, in step (S07), the pH of the water is adjusted to 7–7.3. Even more preferably, in step (S07), the pH of the water is adjusted to 7.1–7.2. This precisely initializes the physicochemical environment of the water body; the water injection depth is slightly lower than the final culture water depth, leaving space for the release of fish fry and avoiding splashing, while this depth already provides sufficient water stability; the water injection speed is a controllable medium flow rate, which can quickly complete the water injection without causing severe scouring of the pool walls or generating excessive bubbles due to excessive water flow; the pH is adjusted precisely to 7–7.3, which is a slightly alkaline to neutral pH range, the optimal pH range for Murray cod growth and also the optimal pH range for nitrifying bacteria activity, thus laying a perfect chemical foundation for subsequent aeration and water conditioning; this creates an initial water body with stable chemical indicators and suitable for biological growth.

[0050] Preferably, in step (S07), oxygen is supplied, and the dissolved oxygen concentration in the water is controlled to be 7 mg / L to 10 mg / L. More preferably, in step (S07), the dissolved oxygen concentration in the water is controlled to be 8 mg / L to 9 mg / L. This establishes an oxygen-rich environment with extremely high dissolved oxygen levels; meets the high oxygen consumption requirements, as both Murray cod and nitrifying bacteria are high oxygen-consuming organisms. Raising the dissolved oxygen to near-saturation levels in advance provides ample "oxygen fuel" for their life activities; promotes oxidative degradation, as high dissolved oxygen accelerates the oxidative decomposition of residual disinfectants and potentially existing organic matter in the water, further purifying the water quality; and creates a stress buffer, as the extremely high initial dissolved oxygen provides a buffer against the temporary stress that may occur when fish fry are introduced, ensuring that oxygen will never become a limiting factor. The water body has extremely sufficient dissolved oxygen, making thorough preparations for the introduction of biological organisms.

[0051] Preferably, the aeration time in step (S07) is 24h to 48h. More preferably, the aeration time in step (S07) is 30h to 42h. More preferably, the aeration time in step (S07) is 32h to 40h. More preferably, the aeration time in step (S07) is 34h to 38h. More preferably, the aeration time in step (S07) is 36h. Water "maturement" and stabilization; gas exchange, continuous aeration thoroughly dissipates potentially water-soluble harmful gases such as hydrogen sulfide, and balances the oxygen and carbon dioxide concentrations in the water with those in the atmosphere; water quality stabilization, allowing sufficient time for the various chemical indicators of the water, such as pH and hardness, to stabilize after pH adjustment and disinfectant rinsing; biological activation, although mainly carried out in the return well for bacterial cultivation, vigorous aeration also helps some beneficial microorganisms inherent in the water to begin to recover and become active; time science, limiting the time range to an empirical time sufficient to complete the above physicochemical processes, making the water "alive" and reaching a stable state; obtaining a pool of "alive," stable, hyper-oxygenated, and chemically perfect "mature water," ready for safe stocking of fish fry at any time. Water injection rate control and aeration treatment promote uniform distribution of dissolved oxygen in the water, meeting the dissolved oxygen requirements of Murray cod; precise control of water temperature and pH to a suitable range for fish reduces stress response; continuous aeration ensures the dissipation of residual chlorine and water quality stability, providing a clean water source for subsequent stocking of fish fry. Risk control is moved to the extreme, with thorough disinfection and precise aquatic environment initialization eliminating almost all foreseeable pathogenic and environmental risks before fry stocking. Parameters are highly optimized and quantified; each parameter—time, concentration, depth, speed, pH, DO, and duration—is not an estimate but an optimal solution verified by theory and practice, making the operational results highly predictable and repeatable. Systemic thinking is applied throughout; the correlation between water injection depth and aquaculture depth, and the coordination of disinfection time with the progress of other subsystems, all demonstrate a strong holistic and synchronous approach. An absolutely advantageous environment is created; through artificial intervention—adjusting pH and increasing oxygen—the aquatic environment is adjusted to an "absolutely optimal" state far exceeding the "qualified" level, providing the highest starting point and greatest guarantee for biological growth.

[0052] Preferably, in step (S08), the length of the Murray cod fry selected is 10cm to 15cm. More preferably, the length of the Murray cod fry selected in step (S08) is 11cm to 14cm. Even more preferably, the length of the Murray cod fry selected in step (S08) is 12cm to 13cm. Selecting fry of the optimal starting size demonstrates strong resistance; fry of this size have passed the most vulnerable stage of fry development, significantly enhancing their adaptability to environmental changes and disease resistance, resulting in a survival rate far higher than smaller fry; the growth cycle is controllable, and starting farming at this size makes growth rate and market time easier to predict and plan, facilitating commercial production management; it significantly reduces mortality in the early stages of farming, increases the success rate of farming, and ensures the stability of the production plan.

[0053] Preferably, in step (S08), (S08-1) Murray cod fry are selected and soaked in saline solution; soaking in saline solution disinfects the Murray cod and reduces the risk of pathogen introduction; the gradient pool water mixing and floating process gradually balances the water temperature and water quality, reducing the stress response of the fry; (S08-2) the Murray cod fry soaked in step (S08-1) are placed in plastic bags; (S08-3) the plastic bags from step (S08-2) are placed on the surface of the aquaculture pond and floated; the floating of the plastic bags allows the temperature to adapt, enabling the fish to... The water temperature inside the transport bag gradually and evenly matches the temperature of the rearing pond, avoiding temperature shocks; (S08-4) Add pond water to the plastic bag from step (S08-3); gradually add pond water to allow the fish fry to adapt to the subtle differences in pH, dissolved oxygen, and ion concentration in the rearing pond water, ensuring a smooth transition of their physiological functions, especially osmotic pressure regulation; (S08-5) Transfer the Murray cod fry from the plastic bag in step (S08-4) into the rearing pond in step (S07) for rearing. This standardized procedure for releasing fry minimizes stress during the release process; it significantly smooths the transition of the fry from the transport environment to the new environment, minimizing release stress and is a crucial step in achieving ultra-high survival rates.

[0054] Preferably, the concentration of the saline solution in step (S08-1) is 3% to 5%. More preferably, the concentration of the saline solution in step (S08-1) is 4%.

[0055] Preferably, the immersion time in step (S08-1) is 10 min to 15 min. More preferably, the immersion time in step (S08-1) is 11 min to 14 min. Even more preferably, the immersion time in step (S08-1) is 12 min to 13 min. Saltwater immersion is a medicated disinfection bath; the limited concentration of salt water can effectively kill most parasites and some pathogens carried on the fish's body surface and gills, preventing the introduction of exogenous pathogens into the clean aquaculture system.

[0056] Preferably, the floating time in step (S08-3) is 15 min to 20 min. More preferably, the floating time in step (S08-3) is 16 min to 19 min. Even more preferably, the floating time in step (S08-3) is 17 min to 18 min.

[0057] Preferably, in step (S08-4), the water filling time is every 4 to 6 minutes. More preferably, in step (S08-4), the water filling time is every 5 minutes.

[0058] Preferably, in step (S08-4), the amount of water added to the tank each time is 9% to 11% of the plastic bag's volume. More preferably, in step (S08-4), the amount of water added to the tank each time is 10% of the plastic bag's volume.

[0059] Preferably, the stocking density of Murray cod fry in step (S08) is 15 fish / m². 2 ~25 tails / m 2 More preferably, in step (S08), the stocking density of Murray cod fry is 17 fish / m³. 2 ~23 tails / m 2 More preferably, in step (S08), the stocking density of Murray cod fry is 19 fish / m³. 2 ~21 tails / m 2 More preferably, in step (S08), the stocking density of Murray cod fry is 20 fish / m³. 2 Determining the optimal stocking density involves balancing economic benefits with ecological carrying capacity. This density is the maximum sustainable density calculated based on the volume of the stocking pond, water exchange rate, dissolved oxygen supply capacity, and efficiency of the biological filtration system. It maximizes the utilization of facility capacity while ensuring that each fish has sufficient space and resources to grow, avoiding problems such as stress, fighting, and water quality deterioration caused by excessive density. The goal is to maximize yield per unit area while maintaining good animal welfare and water quality.

[0060] Preferably, in step (S08), after introducing Murray cod fry, the concentrations of ammonia nitrogen, nitrite, and total phosphorus in the rearing pond are measured every 3 days, and the ammonia nitrogen concentration is adjusted to 0.1–0.2 mg / L, the nitrite concentration to 0.05–0.1 mg / L, and the total phosphorus concentration to 0.1–0.4 mg / L. More preferably, the ammonia nitrogen concentration is adjusted to 0.12–0.18 mg / L, the nitrite concentration to 0.06–0.09 mg / L, and the total phosphorus concentration to 0.2–0.3 mg / L. Even more preferably, the ammonia nitrogen concentration is adjusted to 0.15 mg / L, the nitrite concentration to 0.08 mg / L, and the total phosphorus concentration to 0.25 mg / L. The pH of the return well is monitored daily and maintained within a suitable range for microorganisms to ensure the efficient operation of the nitrification system and continuous degradation of ammonia nitrogen. Water quality indicators in the aquaculture ponds are regularly tested and adjusted to safe thresholds. Combined with periodic disinfection and deworming treatments, the reproduction of pathogenic microorganisms and parasites is effectively inhibited, ensuring fish health. Chlorine dioxide is used monthly for disinfection to control pathogens while reducing the potential harm of heavy metals to fish.

[0061] Preferably, in step (S08), after introducing Murray cod fry, the hydrogen sulfide concentration in the rearing pond is monitored every week, and the hydrogen sulfide concentration is adjusted to 0.05–0.1 mg / L. More preferably, the hydrogen sulfide concentration is adjusted to 0.06–0.09 mg / L. Even more preferably, the hydrogen sulfide concentration is adjusted to 0.07–0.08 mg / L. Water quality monitoring and control: proactive and preventative water quality management; monitoring of key toxins, such as ammonia nitrogen and nitrite, which are direct toxins produced by fish excrement and can inhibit growth and damage health even at low concentrations; nutrient regulation, including monitoring total phosphorus and unmentioned nitrates, allows for understanding the system's nutrient balance, ensuring sufficient nutrients for plants while preventing excessive nutrient accumulation; hydrogen sulfide monitoring, monitoring this highly toxic gas produced in anaerobic environments, allows for timely detection and removal of potential organic waste deposits in the system; frequency and precision, with high-frequency monitoring every 3 days and extremely precise concentration control, reflects exceptionally high management standards, eliminating any water quality problems in their early stages; providing Murray cod with a virtually non-toxic, optimal growth environment is the fundamental guarantee for achieving high growth rates and excellent fish quality.

[0062] Preferably, in step (S08), after introducing Murray cod fry, chlorine dioxide at a concentration of 1-2 mg / L is sprayed into the rearing pond every month. This provides regular preventative disinfection; controls pathogen load; in a closed-loop system, pathogens will gradually proliferate; monthly application of a safe concentration of chlorine dioxide to the entire pond can effectively reduce the total number of pathogens in the water and prevent disease outbreaks; it is safe, as this low concentration has minimal impact on fish and the nitrification system, but is sufficient to inhibit pathogens, making it a "health-preserving" measure; it significantly reduces the chance of disease occurrence, reduces or even avoids the use of therapeutic drugs, and meets the requirements of green and healthy aquaculture. This is a textbook example of stress management. The fish fry stocking procedure perfectly embodies best practices in aquaculture, with each step designed to reduce a specific stressor, demonstrating a high degree of scientific rigor. Data-driven precision management controls key indicators such as ammonia nitrogen and nitrite within extremely strict and precise ranges. This requires frequent adjustments based on real-time monitoring data, representing a "targeted" water quality management approach that is far more effective than traditional extensive methods. Prevention is better than cure; the entire management strategy is preventative—preventing stress, disease, and water quality deterioration—rather than reactive remediation. It achieves a balance between animal welfare and economic benefits. Optimized stocking density and an ideal aquatic environment ensure the health and well-being of fish—free from stress and poisoning—while maximizing economic benefits due to increased survival rates and growth rates.

[0063] Preferably, the method also includes the step (S09) of feeding extruded floating feed into the culture pond of step (S08) from April to June, replenishing water and implementing water circulation. This involves intensive feeding management during the optimal growth season; climate matching, as April to June is spring to early summer, when water temperatures continuously rise and stabilize within the optimal growth temperature range for Murray cod. At this time, fish have vigorous metabolism, strong appetite, and high digestive and absorption efficiency; and a growth spurt, where feeding high-nutrient feed maximizes fish growth and weight gain, shortening the culture cycle. This method capitalizes on the golden growth period of the year, achieving the highest feed conversion efficiency and growth rate.

[0064] Preferably, the extruded floating feed in step (S09) contains 45%–50% crude protein and 5%–10% crude fat. More preferably, the extruded floating feed in step (S09) contains 46%–49% crude protein and 6%–9% crude fat. Even more preferably, the extruded floating feed in step (S09) contains 47%–48% crude protein and 7%–8% crude fat.

[0065] Preferably, the extruded floating feed used in step (S09) is extruded floating feed for California bass. This provides precisely matched nutrition; high protein requirements: as a carnivorous fish, Murray cod has extremely high protein requirements, with 45%–50% crude protein content being the material basis for its rapid growth and muscle accumulation; suitable fat levels: 5%–10% crude fat provides high energy, conserving protein and allowing it to be used more for growth rather than energy, while also providing essential fatty acids; using California bass feed: California bass is also a high-end carnivorous fish, and its commercially available extruded feed formulas are mature, readily available, and of stable quality. The nutritional requirements of both are highly similar, directly using this feed eliminates the high cost and uncertainty of specially customized feed; balanced nutrition: it meets all the nutrients required for Murray cod's maximum growth potential, and the feed source is stable and reliable. The extruded California bass feed (48% crude protein and 8% crude fat) basically meets the growth needs of Murray cod. The floating feed ensures that Murray cod floats to the surface to feed, allowing for direct observation of their feeding behavior and timely adjustment of aquaculture management strategies.

[0066] Preferably, in step (S09), the feeding water temperature is 18℃~28℃, the feeding method is 2 to 4 times a day, and the daily feeding amount is 3% to 5% of the body weight of the Murray cod fry. More preferably, in step (S09), the feeding water temperature is 20℃~26℃, the feeding method is 3 times a day, and the daily feeding amount is 4% of the body weight of the Murray cod fry. A refined feeding strategy maximizes feed utilization; the limited water temperature range is the range where Murray cod digestive enzymes have the highest activity, resulting in the highest digestibility and absorption rate when fed at this temperature; small, frequent meals, 2 to 4 times a day, conform to the feeding habits of carnivorous fish, avoiding the digestive burden and feed waste caused by overfeeding; the optimal feeding rate, the limited daily feeding rate is the verified best ratio, which can meet the maximum growth needs while avoiding overfeeding. Overfeeding is the main cause of water quality deterioration - uneaten feed, excessive feces, and increased feed conversion ratio; the fish grow quickly, the feed conversion ratio is low, the water quality load is controllable, and economic benefits are maximized.

[0067] Preferably, the water replenishment in step (S09) is done daily, with the replenishment amount being 2% to 4% of the water volume in the aquaculture pond. More preferably, the replenishment amount is 3% of the water volume in the aquaculture pond. This maintains the system's water balance and water quality stability; replenishes losses caused by evaporation, plant transpiration, and sewage discharge, maintaining the stability of the water level in the aquaculture pond and the total water volume of the system; dilutes nutrients, as the system is cyclical, but regular replenishment of fresh water can slightly dilute certain mineral salts and metabolic products that gradually accumulate in the system and cannot be fully absorbed by plants, preventing their concentration from becoming too high; replenishes trace elements, which are newly introduced trace elements, maintaining the "freshness" of the system environment; maintains the long-term stability of the system's water volume, and has a slight effect on improving water quality.

[0068] Preferably, the water circulation frequency in step (S09) is 6 to 8 times. More preferably, the water circulation frequency in step (S09) is 7 times. This ensures: determining the optimal hydraulic exchange rate; guaranteeing water quality, meaning the water in the entire aquaculture pond is purified 6 to 8 times daily through the return well-biological filter; high circulation frequency ensures that toxic ammonia nitrogen is promptly transported to the biological filter for treatment and guarantees sufficient dissolved oxygen in the aquaculture pond; uniform water quality, as high-frequency water circulation keeps the water quality—temperature, dissolved oxygen, and nutrients—uniform, without dead zones; balancing efficiency and cost, as higher circulation frequency is not always better, as excessive circulation frequency means greater pump energy consumption; providing solid water quality assurance for high-density aquaculture while controlling energy costs. Nutritional precision: Feed selection and feeding strategies are perfectly aligned with the biological characteristics of Murray cod, with no waste or deficiency, demonstrating strong scientific rigor. Practical operation: Directly using mature "California bass feed" rather than pursuing a theoretically "perfect formula" greatly enhances the operability and economy of the program. Refined management: Precise figures such as "daily feeding rate of 4%", "3 times a day", "3% water replenishment", and "7 cycles" are the core of standardized production, ensuring stable and repeatable production results. Systematic approach: Water replenishment and water circulation management link feeding with the water quality maintenance of the entire system, reflecting a complete system operation mindset.

[0069] Preferably, the method also includes the step (S10) of feeding extruded floating feed into the aquaculture pond of step (S09) from July to September, replenishing water, and implementing water circulation. This feeding management adjustment addresses high-temperature stress and protects the health of the fish.

[0070] Preferably, in step (S10), the feeding water temperature is 28℃~32℃, the feeding method is 2 to 3 times a day, and the daily feeding amount is 2% to 3% of the body weight of the Murray cod fry. More preferably, in step (S10), the feeding water temperature is 29℃~31℃, the feeding method is 3 times a day, and the daily feeding amount is 2.5% of the body weight of the Murray cod fry.

[0071] Preferably, in step (S10), when the water temperature is greater than 32°C, the fish are fed once a day, and the amount of feed is 1% of the body weight of the Murray cod fry. To reduce metabolic load, when water temperatures rise to 28℃~32℃, approaching or exceeding the upper limit of the optimal growth temperature for Murray cod, although the fish can still feed, their metabolism accelerates, oxygen consumption increases sharply, and digestive capacity decreases. At this time, reducing the feeding rate from 4% to 2.5% is essentially to reduce the burden on their digestive system and overall physiology, avoiding indigestion, enteritis, and other problems caused by overfeeding under high temperature stress. To avoid extreme risks, when the water temperature exceeds 32℃, Murray cod are in a state of severe heat stress, with a significantly reduced appetite. At this time, feeding only 1% is not aimed at promoting growth, but at maintaining basic survival needs and preventing the fish from becoming weak. At the same time, the minimal feeding amount also means the least amount of metabolic waste ammonia nitrogen is produced, reducing the pressure on the biological filtration system, which is already less efficient at high temperatures. To maintain a "small, frequent meals" approach, even with reduced feeding, three times a day should still be maintained to avoid excessive feeding at a single time, which is in line with their digestive physiology. During the high-temperature period in summer, priority should be given to ensuring the health and survival of the fish, rather than blindly pursuing growth rate, to safely get through the dangerous period.

[0072] Preferably, the water replenishment in step (S10) is daily, with the replenishment amount being 3% to 5% of the water volume in the aquaculture pond. More preferably, the replenishment amount is 4% of the water volume in the aquaculture pond. Increasing the replenishment amount to 4% strengthens system regulation to cope with high-temperature evaporation; it compensates for evaporation losses, as high summer temperatures lead to a significant increase in water evaporation and plant transpiration, and increasing the daily replenishment amount from 3% to 4% primarily aims to maintain the stability of the system's water level and volume; it assists in cooling, as replenishing with cooler fresh water, such as deep well water, can slightly alleviate the upward trend of the system's water temperature, thus playing a role in assisting in cooling; it enhances dilution, as fish stress and uneaten feed decay accelerate under high temperatures, making water quality more prone to deterioration, and increasing the water exchange volume can more effectively dilute the metabolic waste and harmful substances accumulated in the water; and it maintains the system's water balance, having a slight improving effect on water temperature and water quality.

[0073] Preferably, the water circulation frequency in step (S10) is 8 to 12 times. More preferably, the water circulation frequency in step (S10) is 9 to 11 times. Even more preferably, the water circulation frequency in step (S10) is 10 times. Increasing the water circulation frequency to 10 times / day strengthens water quality assurance and addresses the challenges of high temperatures; enhances purification capacity, as fish oxygen consumption and excretion increase under high temperatures, leading to increased biological oxygen demand. Increasing the circulation frequency means more water flows through the biological filter per unit time, which can remove waste such as ammonia nitrogen more quickly and maintain water quality; increases dissolved oxygen, as higher circulation frequencies are usually accompanied by more vigorous aeration or oxygenation, which can significantly improve the dissolved oxygen level of the water body, addressing the contradiction between decreased dissolved oxygen saturation and increased oxygen demand of fish caused by high temperatures; homogenizes water temperature and quality, as enhanced water flow can prevent water stratification under high temperatures, ensuring a uniform environment throughout the system; and significantly enhances the system's water quality maintenance capacity and stability under high-temperature adverse conditions, which is a key engineering measure to prevent summer hypoxia and ammonia nitrogen poisoning. With strong physiological basis, all adjustments are based on a profound understanding of the physiological effects of high temperatures on fish, including changes in digestive enzyme activity, increased oxygen consumption, and stress responses. Management strategies are completely synchronized with biological laws. A model of dynamic and refined management, the plan is not static but dynamically adjusted based on the key environmental factor of real-time water temperature. It addresses the challenges at 29℃~31℃ and >32℃, achieving truly refined and intelligent management. Systematic risk prevention and control are implemented, considering not only feeding but also increasing water replenishment and circulation frequency to comprehensively address the challenges of high temperatures from a systems engineering perspective, including evaporation, water quality deterioration, and hypoxia, forming a multi-dimensional risk prevention and control system. A balance between economy and safety is struck; while reducing feeding during high-temperature periods may seem to inhibit the growth of farmed fish, this is done to avoid larger economic losses due to mass mortality and disease outbreaks, ultimately ensuring overall economic benefits and production safety.

[0074] Preferably, the method also includes the step (S11) of feeding extruded floating feed into the aquaculture pond of step (S10) in October or November, replenishing water and implementing water circulation. Feeding management is adjusted to seize the golden growth period in autumn and resume high-intensity feeding.

[0075] Preferably, in step (S11), the feeding water temperature is 18℃~28℃, the feeding method is 2 to 4 times a day, and the daily feeding amount is 3% to 5% of the body weight of the Murray cod fry. More preferably, in step (S11), the feeding water temperature is 20℃~26℃, the feeding method is 3 times a day, and the daily feeding amount is 4% of the body weight of the Murray cod fry. The environment returns to its optimal state in October and November. Temperatures drop, and water temperatures stabilize within the optimal growth range of 20°C to 26°C for Murray cod. At this time, the fish have fully recovered from the high-temperature stress of summer, and their metabolism and digestive capacity return to peak levels. Compensatory growth occurs; fish possess the ability to "compensate," meaning that after a period of nutritional stress, such as reduced feeding in summer, their growth rate will exceed that of individuals who have consistently been under optimal conditions once optimal conditions are restored. Resuming a high feeding rate of 4% at this time is precisely to fully utilize this physiological characteristic and maximize the recovery of growth lost during the summer. Fattening and building up body weight are also key stages. Increased feeding during this period also helps the fish store energy for winter and strengthens their constitution. Farming efficiency reaches its highest point of the year, with rapid fish growth, making this a crucial sprint stage for achieving high yields throughout the year and ensuring the fish's safe overwintering.

[0076] Preferably, the water replenishment in step (S11) is daily, with the replenishment amount being 2% to 4% of the water volume in the aquaculture pond. More preferably, the replenishment amount is 3% of the water volume in the aquaculture pond. This water replenishment adjustment adapts to environmental changes and returns to the standard water replenishment pattern; evaporation is reduced as autumn temperatures decrease and air humidity increases, significantly weakening water evaporation and plant transpiration in the greenhouse, thus eliminating the need to maintain the high water replenishment levels of summer; system stability is ensured by returning to the standard water replenishment amount, which is sufficient to balance daily losses and maintain slight water dilution, while reducing water resources and potential water treatment costs; and resource utilization is optimized while maintaining system water balance and water quality stability.

[0077] Preferably, the water circulation frequency in step (S11) is 6 to 8 times. More preferably, the water circulation frequency in step (S11) is 7 times. Adjusting the water circulation frequency optimizes energy consumption and returns to the optimal hydraulic efficiency point. With reduced water quality load and increased fish excretion as feeding resumes, the lower water temperature also means a slower metabolic rate for fish and microorganisms, resulting in a lower rate of ammonia and other waste production compared to summer. Therefore, maintaining the high-intensity circulation seen in summer is unnecessary. Balancing energy consumption and effectiveness, the 7-times / day circulation frequency has been reaffirmed as the most economical and effective frequency for handling the current water quality load and maintaining sufficient dissolved oxygen. Adjusting to this level significantly reduces pump operating energy consumption and saves operating costs. Under the premise of absolutely ensuring water quality safety, the system operating cost is significantly reduced, demonstrating the economic benefits of refined management. Following natural laws, management strategies are adjusted synchronously with changes in environmental factors such as water temperature, perfectly conforming to the physiological rhythms of Murray cod and achieving a scientific aquaculture model of "harmony between man and nature." Economic benefits are maximized by fully utilizing compensatory growth physiological characteristics to achieve maximum weight gain with minimal feed costs. The energy consumption of the cycle frequency has been reduced from 10 cycles / day (high energy consumption) to 7 cycles / day (optimal energy consumption), directly lowering electricity costs, a major operating expense. System operation is standardized, reverting to parameters identical to those used in spring, simplifying and standardizing operations, reducing the possibility of errors, and improving operational efficiency. Risk awareness is maintained through autumn fattening, enhancing the fish population's physical condition and preparing for potential winter management challenges such as feeding cessation and low temperatures—a proactive approach to risk management.

[0078] Preferably, the method also includes the step (S12) of feeding extruded floating feed into the aquaculture pond of step (S11) from December to March of the following year, replenishing water and implementing water circulation. The step-by-step adjustment of feeding management, which is precisely adjusted according to the water temperature until feeding is stopped, matches the extremely low metabolic level of the fish and absolutely avoids feeding losses and water pollution.

[0079] Preferably, in step (S12), when the water temperature is 12℃~18℃, the fish are fed 1 to 3 times a day, with a daily feeding amount of 2% to 4% of the body weight of the Murray cod fry. More preferably, in step (S12), when the water temperature is 14℃~16℃, the fish are fed 2 times a day, with a daily feeding amount of 3% of the body weight of the Murray cod fry.

[0080] Preferably, in step (S12), when the water temperature is 10℃~12℃, the fish are fed 1 to 2 times a day, and the daily feeding amount is 1% to 2% of the body weight of the Murray cod fry.

[0081] Preferably, in step (S12), feeding is not performed when the water temperature is below 10℃. At 14℃~16℃, the daily feeding rate is 3%. At this temperature, Murray cod can still weakly ingest and digest food. Maintaining this extremely low feeding rate of 3% aims to maintain basal metabolism and prevent excessive weight loss, rather than pursuing growth. At 10℃~12℃, the daily feeding rate is 1%~2%. The water temperature is close to the physiological critical point, and the activity of digestive enzymes is extremely low. The purpose of feeding becomes to induce minimal activity in the fish to maintain their vitality. The amount of feed should be such that it can be consumed in a very short time, with absolutely no uneaten food. Feeding is stopped at <10℃. When the water temperature is below 10℃, Murray cod enter a state similar to "hibernation," basically not swimming, and their digestive and absorption functions almost stop. Feeding at this time will only result in the feed being excreted undigested or accumulating in the intestines, causing enteritis, which is entirely harmful. Decisively stopping feeding is the most important aspect of winter management; this minimizes the energy consumption of the fish, ensures their safe passage through the winter, and eliminates the risk of death and water quality deterioration due to improper feeding.

[0082] Preferably, the water replenishment in step (S12) is done daily, with the replenishment amount being 1% to 2% of the water volume in the aquaculture pond. This significantly reduces the replenishment amount to 1% to 2%, maintaining a minimum water balance and minimizing heat loss. Evaporation is extremely low; while the temperature difference between the inside and outside of the greenhouse is large in winter, the high humidity results in very little actual evaporation and transpiration. It also provides insulation and energy saving; the newly replenished water is typically very cold, which would lower the overall system water temperature. Reducing the replenishment amount reduces heat loss, helping to maintain a relatively stable system water temperature and lower heating energy consumption. Under the premise of meeting the minimum water replenishment requirements, it plays a supporting role in insulation and water conservation.

[0083] Preferably, the water circulation frequency in step (S12) is 4 to 6 times. More preferably, the water circulation frequency in step (S09) is 5 times. This significant reduction in water circulation frequency, down to 5 times / day, lowers energy consumption and reduces heat loss from the water body; the pollutant load is extremely low, as the amount of feeding is minimal or completely stopped, eliminating almost all sources of pollutants such as fish excrement and uneaten food, thus minimizing the processing pressure on the biological filtration system and eliminating the need for high-frequency circulation; energy saving and consumption reduction, as the water pump is the main energy-consuming unit of the system, reducing the circulation frequency from 7 times to 5 times significantly reduces electricity costs during winter operation; heat preservation, as water loses heat to the environment when flowing in pipes and return wells, reducing the circulation speed also helps reduce this heat loss; and under the premise of absolutely ensuring water quality safety, because the pollution source has been cut off, the system operating cost is significantly reduced, and the system's heat preservation is indirectly assisted. Absolute scientific rigor and safety are paramount. Precisely adjusting or even stopping feeding based on water temperature is the golden rule for managing cold-water fish during winter. Based entirely on fish physiology, it avoids the most common winter fish mortality risks – indigestion, enteritis, and water quality deterioration. Extreme cost control minimizes winter operating costs – feed, electricity, and water – by reducing feeding, water replenishment, and circulation frequency, demonstrating excellent cost-effectiveness management. A strong risk aversion mindset is paramount; the core of the entire winter strategy is "risk avoidance," with all measures being extremely conservative and robust, ensuring safe overwintering as the sole objective. The plan is comprehensive; this winter management plan, together with the spring, summer, and autumn management plans, constitutes a complete production cycle management manual covering the entire year and adapting to various climatic conditions, making the plan universally applicable in any temperate region. Feeding frequency and amount vary according to water temperature; furthermore, due to the open environment and the transpiration and evaporation of *Acorus gramineus*, especially during the high temperatures of summer, significant water loss occurs daily, necessitating regular water replenishment.

[0084] The second technical solution of the present invention: a Murray cod-Acorus calamus recirculating aquaculture system for fish and medicine, comprising a breeding area, a planting area, and a return flow area. The breeding area contains several breeding ponds, each equipped with an aeration unit and a manure discharge unit in the middle. The planting area contains several hydroponic planting beds. The return flow area contains several return flow wells, each with a fish screening unit on one side. A first drain pipe connects the breeding ponds to the hydroponic planting beds, and a second drain pipe connects the hydroponic planting beds to the return flow wells. A circulation pump is located on one side of each return flow well, with an inlet pipe connected to the end of the circulation pump near the return flow well and an outlet pipe connected to the end of the circulation pump near the breeding pond. This invention comprises a fish farming area, a planting area for planting plants, a return flow area for collecting and regulating aquaculture water, an aeration component for increasing dissolved oxygen in the water and promoting water circulation, a manure discharge component for discharging small particulate impurities such as fish feces from the farming pond, and an auxiliary function for catching and transporting fish, a fish screening component for screening the caught fish, separating substandard fish and impurities from the finished fish, a circulation pump for transporting water from the return flow well to the farming pond, a first drain pipe for transporting water overflowing from the farming pond to the hydroponic planting bed for cultivating plants, and a second drain pipe for transporting unabsorbed water from the hydroponic planting bed to the return flow well, thereby achieving water circulation. The farming area, planting area, and return flow area have a height difference of 1-2 meters, reducing the power required for water circulation and saving energy consumption.

[0085] Preferably, the aeration assembly includes a fixing plate detachably connected to the side of the aquaculture pond. A fixing cylinder is detachably connected to the end of the fixing plate furthest from the pond. A drive motor is located inside the fixing cylinder, and an aeration shaft is located below the drive motor. An aeration umbrella is located at the bottom end of the aeration shaft, and the output end of the drive motor is detachably connected to the aeration umbrella. The aeration umbrella diffuses water flow to the surrounding areas and the bottom, breaking up water stratification, promoting exchange between upper and lower layers, reducing oxygen-deficient areas at the bottom, and inhibiting the accumulation of harmful gases.

[0086] Preferably, the manure discharge assembly includes a mounting bracket. A transmission gear is rotatably connected to one side of the mounting bracket, and a transmission chain is meshed with the side of the transmission gear. A hook is provided at the bottom end of the transmission chain. A drive gear is meshed with the side of the transmission chain away from the transmission gear. A driven gear is provided below the drive gear and meshes with the transmission chain. The drive gear is rotatably connected to the mounting bracket. A transmission turntable is rotatably connected to the side of the mounting bracket away from the drive gear. The rotation shaft of the transmission turntable is fixedly connected to the drive gear. A drive belt is meshed with the side of the transmission turntable, and a drive turntable is meshed with the side of the drive belt away from the transmission turntable. A stepper motor is provided on one side of the drive turntable, and the output end of the stepper motor is fixedly connected to the drive turntable. A frame is fixedly connected below the stepper motor. The hook is used to suspend and transport the fish basket, and the hook can be moved above the fish inlet tank, allowing for convenient and quick pouring of water and fish from the fish basket into the fish inlet tank.

[0087] Preferably, a side baffle is rotatably connected to one side of the frame, and a bottom baffle is provided below the side baffle. The bottom baffle is rotatably connected to the frame. A first bevel gear is fixedly connected to the bottom end of the rotating shaft of the side baffle, and a second bevel gear is fixedly connected to the side of the rotating shaft of the bottom baffle. The first bevel gear and the second bevel gear mesh with each other. A movable plate is fixedly connected to the middle of the rotating shaft of the bottom baffle, and a spring is fixedly connected to the top of the movable plate. The end of the spring away from the movable plate is fixedly connected to the frame. The side baffle and the bottom baffle can form a simple enclosure, which can contain some fish, making it easier for workers to catch them. In addition, workers can move any side baffle, using the bevel gear transmission to the bottom baffle to achieve rapid opening and closing. In the absence of external force, the spring can be used to control the natural state of the bottom baffle. For example, in the natural state, the contraction force of the spring can be used to keep the bottom baffle always open, without enclosing the fish.

[0088] Preferably, a driver is located in the middle of the frame, and a drive shaft is located below the driver. The output end of the driver is fixedly connected to the drive shaft, and a propeller is located at the bottom end of the drive shaft. A bracket is detachably connected to the bottom of the frame, a filter disc is detachably connected to the inner side of the bracket, and a water-blocking ring is detachably connected to the outer side of the bracket. The filter disc is used to screen small particulate impurities such as fish feces, and the propeller is used to promote water flow towards the filter disc, thereby improving screening efficiency.

[0089] Preferably, the bottom of the aquaculture pond is provided with a manure discharge outlet, and a manure discharge pipe is connected to the side of the manure discharge outlet away from the aquaculture pond. The end of the manure discharge pipe away from the manure discharge outlet is connected to a return well. A first filter plate is provided on the side of the return well near the manure discharge outlet, a second filter plate is provided on one side of the first filter plate, and a third filter plate is provided on one side of the second filter plate. The manure discharge pipe is used to transport aquaculture wastewater carrying small particulate impurities such as fish feces to the return well. The first filter plate is used to block the aquaculture water and the water transported from the planting area, forming a water treatment area in the return well. The second filter plate forms a fish fry temporary storage area in the return well, used to temporarily store fish fry screened from the fish trough. The third filter plate forms a fish product temporary storage area in the return well, used to temporarily store fish products screened from the fish trough.

[0090] Preferably, the fish screening assembly includes a diversion box disposed on the side of the return well. A fish inlet trough is detachably connected to one side of the diversion box. A first limiting ring is disposed on one side of the fish inlet trough and is connected to the diversion box. A main rotating ring is rotatably connected to the inner side of the first limiting ring. A first tubular screen is fixedly connected to the side of the main rotating ring away from the fish inlet trough. A first secondary rotating ring is detachably connected to the end of the first tubular screen away from the main rotating ring. A second limiting ring is rotatably connected to the outer side of the first secondary rotating ring and is connected to the diversion box. A second tubular screen is detachably connected to the side of the first secondary rotating ring away from the first tubular screen. A second secondary rotating ring is detachably connected to the end of the second tubular screen away from the first secondary rotating ring. A third limiting ring is rotatably connected to the outer side of the second secondary rotating ring and is connected to the diversion box. The fish inlet trough is used to put fish and water in; the first limiting ring restricts the main rotating ring in the diversion box, and the first limiting ring is higher than the second limiting ring, and the second limiting ring is higher than the third limiting ring, so that the first tubular screen and the second tubular screen are tilted as a whole, so that the fish naturally move towards the direction of fish outlet under the influence of gravity; the main rotating ring is used to drive the first tubular screen to rotate; the first tubular screen is used to screen small particulate impurities and water; the second tubular screen is used to screen fish fry that have not reached the required size.

[0091] Preferably, a drive belt is engaged with the side of the main rotating ring, and a driven pulley is engaged with the end of the drive belt away from the main rotating ring. A drive column is fixedly connected to one side of the driven pulley, and the side of the drive column is rotatably connected to the distribution box. A main rotating pulley is fixedly connected to the end of the drive column away from the driven pulley, and a synchronous belt is engaged with the side of the main rotating pulley. A servo motor is engaged with the end of the synchronous belt away from the main rotating pulley. The servo motor provides power for the rotation of the main rotating ring, thereby enabling screening using the first and second tubular screens.

[0092] Preferably, a filter groove is provided below the first limiting ring, a screen is provided at the bottom of the filter groove, a fish sieve is provided on the side of the filter groove, a fish outlet is provided on the side of the fish sieve away from the filter groove, a spiral filter is provided below the filter groove, an infusion pipe is detachably connected to the top of the spiral filter, an electric motor is provided on the side of the spiral filter, the output end of the electric motor is fixedly connected to the spiral filter, an inlet is provided at the top of the spiral filter, an outlet is provided at the bottom of the spiral filter, a collection tank is provided below the outlet, a sieve plate is provided on the side of the collection tank, a water storage tank is provided on the side of the sieve plate away from the collection tank, a water pump is provided on the side of the water storage tank, a water delivery pipe is provided on the side of the water pump, and a sprinkler is provided at the top of the water delivery pipe. The filter tank is used to receive small particulate impurities and water flowing down from the first tubular screen. Most of the water passes through the screen and enters the collection tank. The remaining impurities and water enter the spiral filter through the inlet for spiral filtration. The filtered water flows into the return well along the delivery pipe. The remaining impurities and a small amount of water leave the spiral filter from the outlet and enter the collection tank. The screen plate is used to block impurities in the collection tank. The water storage tank is used to store the water screened by the screen plate. The water pump draws water from the water storage tank and delivers it to the sprinkler. The sprinkler sprays water onto the distribution box to replenish the water lost by the fish during screening.

[0093] The present invention has the following beneficial effects: (1) It utilizes microorganisms to convert fish excrement into nutrients that plants can absorb, thereby achieving an ecological cycle of "raising fish without changing the water and growing vegetables without fertilizing"; Murray cod has high economic value and is suitable for high-density aquaculture in recirculating water, with a good market prospect; Acorus calamus is not only an aquatic plant but also a traditional Chinese medicine with higher economic value and higher benefits than ordinary vegetables. Its root system is well-developed, with strong water purification ability, and it is shade-tolerant and adaptable to hydroponics, making it very suitable for planting in greenhouses with Murray cod, which prefers shade; (2) The entire system fully follows the three core elements of the fish-medicine symbiosis system: fish farming, plant hydroponics, and microbial nitrification. The zoning design and the multi-layer filter structure of the return well all reflect professional standards; (3) Considering the shade-loving characteristics of Murray cod, an adjustable shade canopy is specially designed, reflecting a deep understanding and respect for the physiological habits of the aquaculture object; Naphthaleneacetic acid is used to promote root growth, humic acid and dihydrogen phosphate are used to promote root growth. Potassium foliar fertilizer supplementation has entered the field of refined agricultural management, aiming to maximize the output and efficiency of plants; (4) The breeding area is used for raising fish; the planting area is used for planting plants; the return area is used for collecting and regulating the breeding water; the aeration component is used to increase dissolved oxygen in the water and promote water circulation; the manure discharge component is used to discharge small particulate impurities such as fish manure in the breeding pond, and has the function of assisting in catching and transporting; the fish screening component is used to screen the caught fish and separate the fish and impurities that do not meet the size standard from the finished fish; the circulation pump is used to transport the water in the return well to the breeding pond, the first drain pipe transports the water overflowing from the breeding pond to the hydroponic planting bed to cultivate plants, and the second drain pipe is used to transport the unabsorbed water in the hydroponic planting bed to the return well, thereby realizing the circulation of water; there is a height difference of 1 to 2 m between the breeding area, the planting area and the return area, which reduces the power required for water circulation and saves energy consumption. Attached Figure Description

[0094] Figure 1 This is an overall structural diagram of the present invention; Figure 2 This is a schematic diagram of the aeration component of the present invention; Figure 3 This is a schematic diagram of the manure discharge component of the present invention; Figure 4 This is a schematic diagram of the frame of the present invention; Figure 5 This is a schematic diagram of the side baffle of the present invention; Figure 6 This is a schematic diagram of the water-proof ring of the present invention; Figure 7 This is a schematic diagram of the reflux well of the present invention; Figure 8 This is a schematic diagram of the fish-screening component of the present invention; Figure 9 This is a schematic diagram of the fish inlet tank of the present invention; Figure 10 This is a schematic diagram of the water storage tank of the present invention; Figure 11 This is a schematic diagram of the sprinkler of the present invention; Figure 12 This is a schematic diagram of the overall process of the present invention; Figure 13 This is a schematic diagram of water quality testing according to the present invention; Figure 14 This is a schematic diagram of the greenhouse for planting and breeding according to the present invention.

[0095] The labels in the attached diagram are as follows: 100, Aquaculture area; 200, Planting area; 300, Recirculation area; 101, Aquaculture pond; 400, Aeration assembly; 500, Manure discharge assembly; 201, Hydroponic planting bed; 301, Recirculation well; 600, Fish screening assembly; 102, First drain pipe; 202, Second drain pipe; 302, Circulation pump; 3021, Inlet pipe; 3022, Outlet pipe; 401, Fixing plate; 402, Fixing cylinder; 403, Drive motor; 404, Aeration shaft; 405, Aeration umbrella; 501, Mounting bracket; 502, Transmission. Gear; 503, Transmission Chain; 5031, Hook; 504, Drive Gear; 5041, Driven Gear; 5042, Transmission Turntable; 5043, Drive Belt; 5044, Drive Turntable; 5045, Stepper Motor; 505, Frame; 5051, Side Baffle; 5052, Bottom Baffle; 50511, First Bevel Gear; 50521, Second Bevel Gear; 50522, Movable Plate; 50523, Spring; 506, Driver; 507, Drive Shaft; 508, Propeller; 509, Bracket; 5091, Filter Disc; 5 092. Water-blocking ring; 103. Manure outlet; 104. Manure pipe; 303. First filter plate; 304. Second filter plate; 305. Third filter plate; 601. Diversion box; 602. Fish inlet tank; 603. First limiting ring; 604. Main rotating ring; 6041. First tubular screen; 6042. First driven rotating ring; 6031. Second limiting ring; 6043. Second tubular screen; 6044. Second driven rotating ring; 6032. Third limiting ring; 605. Drive belt; 6051. Driven pulley; 6052. Drive column; 6053. 6054. Main impeller; 6055. Synchronous belt; 6056. Servo motor; 607. Filter tank; 608. Screen; 609. Fish sieve; 6000. Fish outlet; 601. Spiral filter; 602. Electric motor; 603. Inlet pipe; 604. Outlet pipe; 605. Collection tank; 606. Screen plate; 607. Water storage tank; 608. Pumping pipe; 6099. Water pump; 60910. Water delivery pipe; 60911. Sprinkler; 1004. Sunlight-type greenhouse; 1005. Mounting frame. Detailed Implementation

[0096] The present invention will be further described below with reference to the accompanying drawings and embodiments, but this should not be construed as limiting the present invention.

[0097] The Murray cod-Acorus calamus recirculating aquaculture system for fish and medicine includes the following steps: (S01) Constructing a solar-type greenhouse 1004, and planning an aquaculture area, a planting area, and a recirculation area within the greenhouse; (S01) The area of ​​the planting area is larger than the area of ​​the aquaculture area; (S01) The ground level of the aquaculture area is higher than the ground level of the planting area; The ground level of the planting area is higher than the ground level of the recirculation area; The height of the greenhouse in step (S01) is 4m to 6m; (S01) The temperature... The height of the greenhouse is 4.5m to 5.5m; the height of the greenhouse in step (S01) is 5m; the dome of the solar greenhouse in step (S01) is arc-shaped; the outer surface of the dome of the solar greenhouse in step (S01) is covered with insulating material; the area ratio of the planting area to the breeding area in step (S01) is 3 to 4:1; the area ratio of the planting area to the breeding area in step (S01) is 3.5:1; the ground level of the breeding area in step (S01) is higher than that of the planting area. The ground height in the breeding area is 1m to 2m; in step (S01), the ground height in the breeding area is 1.5m higher than the ground height in the planting area; in step (S01), the ground height in the planting area is 0.3m to 1m higher than the ground height in the reflux area; in step (S01), the ground height in the planting area is 0.4m to 0.9m higher than the ground height in the reflux area; in step (S01), the ground height in the planting area is 0.5m to 0.8m higher than the ground height in the reflux area; in step (S01), the ground height in the planting area is higher than the ground height in the reflux area. The ground height of the flow area is 0.6m to 0.7m; an adjustable shading net can also be built outside the solar greenhouse using mounting frame 1005; (S02) Several breeding ponds are built in the breeding area of ​​step (S01), and an adjustable shading shed is built above the breeding area using shading net; the shading rate of the shading shed in step (S02) is 50% to 60%; the shading rate of the shading shed in step (S02) is 55%; the calculation method of the shading rate of the shading shed in step (S02) is as follows.

[0098] In the formula, natural light intensity refers to the light intensity measured outside the shade net using a light intensity meter; light intensity inside the net refers to the light intensity measured inside the shade net using a light intensity meter; in step (S02), the depth of the aquaculture pond is 1.5m to 2.0m, and the area of ​​the aquaculture pond is 15m². 2 ~20m 2 In step (S02), the depth of the aquaculture pond is 1.6m to 1.8m, and the area of ​​the aquaculture pond is 16m². 2 ~18m 2 In step (S02), the depth of the aquaculture pond is 1.7m and the area of ​​the aquaculture pond is 17m². 2(S03) Several hydroponic planting beds are constructed within the planting area of ​​step (S01). Each hydroponic planting bed is equipped with a water inlet and an overflow outlet, with the water inlet lower than the overflow outlet. The height of the hydroponic planting beds in step (S03) is 40cm–50cm, and the area of ​​each hydroponic planting bed is 10m². 2 ~21m 2 In step (S03), the height of the hydroponic planting bed is 42cm to 48cm, and the area of ​​the hydroponic planting bed is 15m². 2 ~20m 2 In step (S03), the height of the hydroponic planting bed is 45cm, and the area of ​​the hydroponic planting bed is 18m². 2 In step (S03), the diameter of the inlet is φ20mm~40mm, and the diameter of the overflow outlet is φ20mm~40mm; in step (S03), the diameter of the inlet is φ25mm~35mm, and the diameter of the overflow outlet is φ25mm~35mm; in step (S03), the diameter of the inlet is φ30mm, and the diameter of the overflow outlet is φ30mm; in step (S03), the inlet and overflow outlet are diagonally opposite each other on the hydroponic planting bed. Line setup; in step (S03), the height of the water inlet is 3cm to 8cm lower than the overflow outlet; in step (S03), the height of the water inlet is 4cm to 7cm lower than the overflow outlet; in step (S03), the height of the water inlet is 5cm to 6cm lower than the overflow outlet; a layer of expanded clay pebbles is laid in the hydroponic planting bed in step (S03); the expanded clay pebbles in the expanded clay pebbles layer are prepared by selecting coarse expanded clay pebbles with a particle size of 10 to 20mm and using a secondary chemical solution with a concentration of 20 to 50ppm. Disinfected by soaking in sodium hypochlorite solution, then rinsed; coarse ceramsite with a particle size of 12-18mm is selected and disinfected by soaking in sodium hypochlorite solution with a concentration of 25-45ppm; coarse ceramsite with a particle size of 14-16mm is selected and disinfected by soaking in sodium hypochlorite solution with a concentration of 30-40ppm; coarse ceramsite with a particle size of 15mm is selected and disinfected by soaking in sodium hypochlorite solution with a concentration of 35ppm; the thickness of the ceramsite layer in step (S03) is 20cm-30cm; the thickness of the ceramsite layer in step (S03) is 22cm-28cm; the thickness of the ceramsite layer in step (S03) is 25cm; (S04) several return wells are built in the return zone of step (S01), and volcanic rock layer, quartz sand layer and biosphere layer are laid in the return wells from bottom to top, and water is injected into the return wells; the depth of the return wells in step (S04) is 1m-2m, and the volume of the return wells is 40m³. 3 ~60m 3 In step (S04), the depth of the reflux well is 1.2m to 1.8m, and the volume of the reflux well is 45m³. 3 ~55m 3 In step (S04), the depth of the reflux well is 1.5m, and the volume of the reflux well is 50m³. 3In step (S04), the thickness of the volcanic rock layer is 50mm–80mm, the thickness of the quartz sand layer is 20mm–30mm, and the thickness of the biosphere layer is 5mm–10mm; in step (S04), the thickness of the volcanic rock layer is 55mm–75mm, the thickness of the quartz sand layer is 22mm–28mm, and the thickness of the biosphere layer is 6mm–9mm; in step (S04), the thickness of the volcanic rock layer is 60mm–70mm, and the thickness of the quartz sand layer is 24mm–26mm. The thickness of the biosphere layer is 7mm-8mm; in step (S04), the thickness of the volcanic rock layer is 65mm, the thickness of the quartz sand layer is 25mm, and the thickness of the biosphere layer is 7.5mm; in step (S04), active nitrifying bacteria solution is inoculated into the water of the return well, and oxygen is supplied to the return well for aeration and cultivation, controlling the dissolved oxygen concentration in the water to be 7mg / L-10mg / L; in step (S04), the concentration of active nitrifying bacteria solution inoculated into the water of the return well is 200-300mL / m 3 The concentration of the inoculated active nitrifying bacteria solution is 220–280 mL / m³. 3 The concentration of the inoculated active nitrifying bacteria solution is 240–260 mL / m³. 3 The concentration of the inoculated active nitrifying bacteria solution was 250 mL / m³. 3The aeration and cultivation period is 2 to 4 weeks; the aeration and cultivation period is 2.5 to 3.5 weeks; the aeration and cultivation period is 3 weeks; the water quality of the return well is tested every 2 to 4 days during the aeration and cultivation period; the water quality of the return well is tested every 3 days during the aeration and cultivation period; in step (S04), the pH value and water temperature of the return well are tested daily, and the pH value is adjusted to 7.0 to 7.5; the pH value is adjusted to 7.1 to 7.4; the pH value is adjusted to 7.2 to 7.3; (S05) Select the seedlings of Acorus gramineus and bury them in the hydroponic planting bed of step (S03), fill the water to submerge the roots of the seedlings, and spray with naphthaleneacetic acid; the burying time in step (S05) is 3 to 5 months; the burying time in step (S05) is 3.5 to 5 months. 4.5 months; the burying time in step (S05) is April; in step (S05), the seedling height of *Acorus gramineus* is selected to be 10cm-15cm; in step (S05), the seedling height of *Acorus gramineus* is selected to be 11cm-14cm; in step (S05), the seedling height of *Acorus gramineus* is selected to be 12cm-13cm; in step (S05), the distance between adjacent *Acorus gramineus* seedlings in the hydroponic planting bed is 8cm-10cm; in step (S05), the distance between adjacent *Acorus gramineus* seedlings in the hydroponic planting bed is 9cm; in step (S05), the ceramsite layer of the hydroponic planting bed has several planting holes with a depth of 3cm-5cm, and the *Acorus gramineus* seedlings are buried in the planting holes; the ceramsite layer of the bed has several planting holes with a depth of 3.5cm-4cm.Planting holes of 5cm; several planting holes of 4cm depth are provided on the ceramsite bed; the time for spraying naphthaleneacetic acid in step (S05) is in the evening; the concentration of naphthaleneacetic acid in step (S05) is 50ppm~80ppm; the concentration of naphthaleneacetic acid in step (S05) is 55ppm~75ppm; the concentration of naphthaleneacetic acid in step (S05) is 60ppm~70ppm; the concentration of naphthaleneacetic acid in step (S05) is 65ppm; (S06) after the Acorus calamus seedlings in step (S05) have grown for a period of time, some leaves are cut off and humic acid and potassium dihydrogen phosphate are sprayed; the growth of the Acorus calamus seedlings in step (S06) The growth period is 3-6 months; in step (S06), the growth period of the *Acorus gramineus* seedlings is 4-5 months; in step (S06), leaves with a length of 30cm-40cm are cut; in step (S06), leaves with a length of 32cm-38cm are cut; in step (S06), leaves with a length of 34cm-3cm are cut; the spraying method in step (S06) is foliar spraying; the spraying time in step (S06) is evening; the concentration of humic acid in step (S06) is 200ppm-300ppm; the concentration of humic acid in step (S06) is 210ppm-290ppm; in step (S06), the humic acid... The concentration of humic acid is 220ppm to 280ppm; the concentration of humic acid in step (S06) is 230ppm to 270ppm; the concentration of humic acid in step (S06) is 240ppm to 260ppm; the concentration of humic acid in step (S06) is 250ppm; the concentration of potassium dihydrogen phosphate in step (S06) is 0.1% to 0.2%; the concentration of potassium dihydrogen phosphate in step (S06) is 0.15%; (S07) after disinfecting the aquaculture pond in step (S02), water is added, the pH of the water is adjusted, oxygen is supplied to the aquaculture pond, and it is aerated; the disinfection time in step (S07) is 3 to 5 months. The disinfection time in step (S07) is 3.5 to 4.5 months; the disinfection time in step (S07) is 4 months; in step (S07), the aquaculture pond is disinfected with a chlorine dioxide solution with a concentration of 1 mg / L to 2 mg / L, rinsed, and then filled with water; the aquaculture pond is disinfected with a chlorine dioxide solution with a concentration of 1.2 mg / L to 1.8 mg / L; the aquaculture pond is disinfected with a chlorine dioxide solution with a concentration of 1.5 mg / L; the water filling depth in step (S07) is 1.2 m to 1.5 m; the water filling depth in step (S07) is 1.3 m to 1.4 m; the water filling speed in step (S07) is 0.2 m / s. 3 / s~0.3m 3 / s; the water injection rate in step (S07) is 0.25m / s. 3 / s; In step (S07), adjust the pH of the water to 6.8–7.5; In step (S07), adjust the pH of the water to 6.9–7.4; In step (S07), adjust the pH of the water to 7–7.3; In step (S07), adjust the pH of the water to 7.1–7.2; In step (S07), supply oxygen and control the dissolved oxygen concentration in the water to 7 mg / L–10 mg / L; In step (S07), control the dissolved oxygen concentration in the water to 8 mg / L–9 mg / L; The aeration time in step (S07) is 24 h–48 h; The aeration time in step (S07) is 30 h–42 h; Step The aeration time in step (S07) is 32h-40h; the aeration time in step (S07) is 34h-38h; the aeration time in step (S07) is 36h; (S08) Murray cod fry are selected and placed into the culture pond of step (S07) for culture; the length of the Murray cod fry selected in step (S08) is 10cm-15cm; the length of the Murray cod fry selected in step (S08) is 11cm-14cm; the length of the Murray cod fry selected in step (S08) is 12cm-13cm; the stocking density of the Murray cod fry in step (S08) is 15 fish / m². 2 ~25 tails / m 2 In step (S08), the stocking density of Murray cod fry is 17 fish / m³. 2 ~23 tails / m 2 In step (S08), the stocking density of Murray cod fry is 19 fish / m³. 2 ~21 tails / m 2 In step (S08), the stocking density of Murray cod fry is 20 fish / m³. 2In step (S08), after introducing Murray cod fry, the concentrations of ammonia nitrogen, nitrite, and total phosphorus in the culture pond are tested every 3 days. The ammonia nitrogen concentration is adjusted to 0.1–0.2 mg / L, nitrite to 0.05–0.1 mg / L, and total phosphorus to 0.1–0.4 mg / L; the ammonia nitrogen concentration is adjusted to 0.12–0.18 mg / L, nitrite to 0.06–0.09 mg / L, and total phosphorus to 0.2–0.3 mg / L; the ammonia nitrogen concentration is adjusted to 0.15 mg / L, nitrite to 0.08 mg / L, and total phosphorus to 0.25 mg / L. In step (S08), after introducing Murray cod fry, the sulfide concentration in the culture pond is tested every week. The hydrogen concentration was adjusted to 0.05–0.1 mg / L; the hydrogen sulfide concentration was adjusted to 0.06–0.09 mg / L; the hydrogen sulfide concentration was adjusted to 0.07–0.08 mg / L; in step (S08), after introducing Murray cod fry, chlorine dioxide with a concentration of 1–2 mg / L was sprayed into the breeding pond every month; in step (S08), (S08-1) Murray cod fry were selected and soaked in saline solution; the concentration of saline solution in step (S08-1) was 3%–5%; the concentration of saline solution in step (S08-1) was 4%; the soaking time in step (S08-1) was 10 min–15 min; the soaking time in step (S08-1) was 11 min–1 4 min; the immersion time in step (S08-1) is 12 min to 13 min; (S08-2) after immersion in step (S08-1), put the Murray cod fry into plastic bags; (S08-3) place the plastic bags from step (S08-2) on the surface of the aquaculture pond and let them float; the floating time in step (S08-3) is 15 min to 20 min; the floating time in step (S08-3) is 16 min to 19 min; the floating time in step (S08-3) is 17 min to 18 min; (S08-4) add pond water to the plastic bags from step (S08-3); the time for adding pond water in step (S08-4) is every 4 min to 6 min; step (S08- 4) The water filling time is every 5 minutes; the water volume added to the tank each time in step (S08-4) is 9% to 11% of the plastic bag volume; the water volume added to the tank each time in step (S08-4) is 10% of the plastic bag volume; (S08-5) The Murray cod fry in the plastic bag in step (S08-4) are put into the breeding tank in step (S07) for breeding; (S09) From April to June, extruded floating feed is fed into the breeding tank in step (S08), water is added and water circulation is performed; the extruded floating feed in step (S09) contains 45% to 50% crude protein and 5% to 10% crude fat; the extruded floating feed in step (S09) contains 46% to 49% crude protein and 6% to 9% crude fat;The extruded floating feed in step (S09) contains 47%–48% crude protein and 7%–8% crude fat; the extruded floating feed used in step (S09) is California bass extruded floating feed; the feeding water temperature in step (S09) is 18℃–28℃, and the feeding method is 2–4 times a day, with a daily feeding amount of 3%–5% of the body weight of the Murray cod fry; the feeding water temperature in step (S09) is 20℃–26℃, and the feeding method is 3 times a day, with a daily feeding amount of 4% of the body weight of the Murray cod fry; the water replenishment in step (S09) is daily, with a replenishment amount of 2%–4% of the water volume in the culture pond; the water circulation frequency in step (S09) is 6–8 times; step (S09) The water circulation in step (S09) is 7 times; (S10) from July to September, extruded floating feed is fed into the breeding pond of step (S09), water is replenished, and water circulation is performed; the feeding water temperature in step (S10) is 28℃~32℃, the feeding method is 2 to 3 times a day, and the daily feeding amount is 2%~3% of the weight of Murray cod fry; the feeding water temperature in step (S10) is 29℃~31℃, the feeding method is 3 times a day, and the daily feeding amount is 2.5% of the weight of Murray cod fry; when the water temperature is greater than 32℃ in step (S10), feeding is done once a day, and the feeding amount is 1% of the weight of Murray cod fry; the water replenishment in step (S10) is done daily, and the water replenishment amount is 3%~5% of the water volume in the breeding pond; the water replenishment amount is the water volume in the breeding pond. The water volume is 4%; the water circulation frequency in step (S10) is 8 to 12 times; the water circulation frequency in step (S10) is 9 to 11 times; the water circulation frequency in step (S10) is 10 times; (S11) from October to November, extruded floating feed is fed into the breeding pond of step (S10), water is replenished and water circulation is performed; the feeding water temperature in step (S11) is 18℃ to 28℃, the feeding method is 2 to 4 times a day, and the daily feeding amount is 3% to 5% of the body weight of Murray cod fry; the feeding water temperature in step (S11) is 20℃ to 26℃, the feeding method is 3 times a day, and the daily feeding amount is 4% of the body weight of Murray cod fry; the water replenishment in step (S11) is daily, and the replenishment amount is the water volume in the breeding pond. 2%–4%; the replenishment water volume is 3% of the water volume in the breeding pond; the water circulation number in step (S11) is 6–8 times; the water circulation number in step (S11) is 7 times; (S12) from December to March of the following year, extruded floating feed is fed into the breeding pond of step (S11), water is replenished and water circulation is performed; when the water temperature in step (S12) is 12℃–18℃, feeding is done 1–3 times a day, and the daily feeding amount is 2%–4% of the body weight of Murray cod fry; when the water temperature in step (S12) is 14℃–16℃, feeding is done 2 times a day, and the daily feeding amount is 3% of the body weight of Murray cod fry; when the water temperature in step (S12) is 10℃–12℃, feeding is done 1–2 times a day, and the daily feeding amount is 1%–2% of the body weight of Murray cod fry;In step (S12), feeding is not performed when the water temperature is below 10℃; water replenishment in step (S12) is done daily, with the replenishment amount being 1% to 2% of the water volume in the breeding pond; the water circulation frequency in step (S12) is 4 to 6 times; the water circulation frequency in step (S09) is 5 times.

[0099] The Murray cod-Acorus calamus recirculating aquaculture system for fish and medicine symbiosis is characterized by the following steps: (S01) Constructing a 5m high, sunlit greenhouse, and planning an aquaculture area, a planting area, and a recirculation area within the greenhouse. The area ratio of the planting area to the aquaculture area is 3-4:1. Adjusting the ground height so that the aquaculture area is 1-2m higher than the planting area, and the planting area is 0.3-1m higher than the recirculation area; (S02) Constructing several enclosures with a depth of 1.5-2.0m and an area of ​​15-20m² within the aquaculture area. 2 (S03) For the breeding ponds, a shade canopy with a shading rate of 50-60% is built above the breeding area using shade netting; (S04) Several canopies with a height of 40-50cm and an area of ​​10-21m² are built on the ground of the planting area. 2 The hydroponic planting bed has a φ20-40mm water inlet at one corner and a φ20-40mm overflow outlet diagonally opposite the inlet. The height of the inlet is 5cm lower than the overflow outlet. Coarse ceramic pebbles with a particle size of 10-20mm are selected, disinfected by soaking in a sodium hypochlorite solution with a concentration of 20-50ppm, and then rinsed before being laid in the hydroponic planting bed as a 25-30cm layer of ceramic pebbles; (S04) Several reflux zones with a depth of 1-2m and a volume of 50m³ are constructed in the reflux area. 3 The return well is filled with volcanic rock with a height of 50-80mm at the bottom, quartz sand with a height of 20-30mm in the middle layer, and biospheres with a height of 5-10mm on top.

[0100] Water is injected into the return well, and then an inoculation concentration of 200–300 mL / m is added to the return well. 3The active nitrifying bacteria solution was used to supply oxygen to the return well, so that the dissolved oxygen concentration in the return well was 7-10 mg / L. The well was aerated and cultured for 2-4 weeks, with the water quality of the return well tested every 3 days during this period; (S05) From March to May, 10-15 cm tall *Acorus gramineus* seedlings were selected. Planting holes with a depth of 3-5 cm were set in the expanded clay layer at a spacing of 8-10 cm. The roots of the *Acorus gramineus* seedlings were then buried in the holes. Water was poured into the hydroponic planting bed to submerge the roots of the *Acorus gramineus* seedlings, and naphthaleneacetic acid at a concentration of 50-80 ppm was sprayed in the evening; (S06) (S07) Three to six months after planting the seedlings of *Acorus gramineus*, measure the leaf length and cut off leaves 30 to 40 cm long, retaining 5 to 7 new leaves. After cutting the leaves, apply 200 to 300 ppm humic acid and 0.1 to 0.2% potassium dihydrogen phosphate by foliar spraying in the evening. From March to May, disinfect the aquaculture ponds with a 1 to 2 mg / L chlorine dioxide solution, rinse, and then fill with water to a depth of 1.2 to 1.5 m, controlling the water flow rate in the ponds to 0.2 to 0.3 m / s. 3 / s, adjust the pH value to 6.8-7.5, supply oxygen to the breeding pond to make the dissolved oxygen concentration 7-10 mg / L, and aerate for 24-48 hours; (S08) Select Murray cod fry of 10-15 cm, soak them in 3-5% saline solution for 10-15 minutes, then put them into plastic bags, and place the plastic bags on the surface of the breeding pond for 15-20 minutes. Add 9-11% pond water to the plastic bags every 4-6 minutes. After adapting to the water temperature, remove the plastic bags and put the Murray cod fry into the breeding pond, making the stocking density 15-25 fish / m 2 (S09) Select extruded floating feed for California bass containing 48% crude protein and 8% crude fat. Monitor water temperature from April to June. When the water temperature is 18-28℃, feed three times a day, with a daily feed amount of 3-4% of the Murray cod fry's body weight. Add 2% water daily and perform water circulation seven times. (S10) Monitor water temperature from July to September. When the water temperature is 28-32℃, feed twice a day, with a daily feed amount of 2-3% of the Murray cod fry's body weight. When the water temperature is above 32℃, feed once a day, with a daily feed amount of 1% of the Murray cod fry's body weight. Add 4% water daily and perform water circulation. Circulate water 10 times; (S11) Detect water temperature in October and November. When the water temperature is 18-28℃, feed 3 times a day, with a daily feed amount of 3-4% of the weight of the Murray cod fry. Add 2% water daily and perform water circulation 7 times; (S12) Detect water temperature from December to March of the following year. When the water temperature is 12-18℃, feed 2 times a day, with a daily feed amount of 2-3% of the weight of the Murray cod fry. When the water temperature is 10-12℃, feed once a day, with a daily feed amount of 1% of the weight of the Murray cod fry. Do not feed when the water temperature is below 10℃. Add 1% water daily and perform water circulation 5 times.

[0101] Example 1: As Figure 12 , Figure 13 and Figure 14 The Murray cod-Acorus calamus recirculating aquaculture system for fish and medicine symbiosis, as shown, includes the following steps:

[0102] (S01) Construct a 5m high solar greenhouse. Within the greenhouse, plan a breeding area, a planting area, and a reflux area. The area ratio of the planting area to the breeding area is 3:1. Adjust the ground height so that the breeding area is 1m higher than the planting area, and the planting area is 0.3m higher than the reflux area. (S02) Construct several breeding ponds, each 1.5m deep and 15m² in area, within the breeding area. Construct a 50% shading net above the breeding area. (S03) Construct several hydroponic planting beds, each 40cm high and 10m² in area, within the planting area. A φ20mm water inlet is set at one corner of the hydroponic planting bed, and a φ20mm overflow outlet is set diagonally opposite the water inlet. The height of the water inlet is 5cm lower than that of the overflow outlet. Coarse ceramic pebbles with a particle size of 10mm are selected, disinfected by soaking in a sodium hypochlorite solution with a concentration of 20ppm, rinsed, and then laid in the hydroponic planting bed as a 25cm layer of ceramic pebbles; (S04) Several return wells with a depth of 1m and a volume of 50m³ are built in the return area. A 50mm high layer of volcanic rock is laid at the bottom of the return well, a 20mm high layer of quartz sand is filled in the middle, and a 5mm high layer of covering is laid on top. Bio-balls; Water is injected into the return well, and then an active nitrifying bacteria solution with a concentration of 200 mL / m³ is inoculated into the return well. Oxygen is supplied to the return well to make the dissolved oxygen concentration in the return well 7 mg / L. Aeration culture is carried out for 2 weeks, and the water quality of the return well is tested every 3 days during this period; (S05) From March to May, 10 cm tall Acorus gramineus seedlings are selected. Planting holes with a depth of 3 cm are set in the ceramsite layer with a plant spacing of 8 cm. Then, the roots of the Acorus gramineus seedlings are buried in the holes. Water is injected into the hydroponic planting bed to submerge the roots of the Acorus gramineus seedlings. In the evening, a solution with a concentration of 5 mg / L is sprayed. 0 ppm naphthaleneacetic acid; (S06) Three to six months after planting Acorus gramineus seedlings, measure the leaf length of Acorus gramineus, cut off leaves with a length of 30 cm, and retain 5 new leaves. After cutting the leaves, in the evening, apply 200 ppm humic acid and 0.1% potassium dihydrogen phosphate by foliar spraying; (S07) From March to May, disinfect the breeding pond with a 1 mg / L chlorine dioxide solution, rinse and fill with water to a depth of 1.2 m, control the water flow rate in the breeding pond to 0.2 m³ / s, and adjust the pH value to 6.8. Supply oxygen to the breeding pond to achieve a dissolved oxygen concentration of 7 mg / L and aerate for 24 hours; (S08) Select Murray cod fry of 10-15 cm, soak them in a 3% saline solution for 10 minutes, then put them into plastic bags and place the bags on the surface of the breeding pond for 15 minutes. Add 9% pond water to the bags every 4 minutes. After they adapt to the water temperature, remove the bags and release the Murray cod fry into the breeding pond at a stocking density of 15 fish / m²; (S09) Select extruded floating feed for California bass containing 48% crude protein and 8% crude fat. Test the water temperature from April to June. When the water temperature is 18-28℃, feed the fish fry three times a day at a daily rate of 3% of their body weight. Add 2% water daily and perform water circulation seven times.

[0103] (S10) Detect water temperature from July to September. When the water temperature is 28-32℃, feed twice a day at a daily amount of 2% of the weight of the Murray cod fry. When the water temperature is above 32℃, feed once a day at a daily amount of 1% of the weight of the Murray cod fry. Add 4% water daily and perform water circulation 10 times.

[0104] (S11) Monitor the water temperature in October and November. When the water temperature is 18-28℃, feed the fish fry three times a day, with a daily feed amount of 3% of the body weight of the Murray cod fry. Add 2% of the water daily and perform water circulation seven times. (S12) Monitor the water temperature from December to March of the following year. When the water temperature is 12-18℃, feed the fish fry twice a day, with a daily feed amount of 2% of the body weight of the Murray cod fry. When the water temperature is 10-12℃, feed the fish fry once a day, with a daily feed amount of 1% of the body weight of the Murray cod fry. Do not feed the fish when the water temperature is below 10℃. Add 1% of the water daily and perform water circulation five times.

[0105] This embodiment sets up 8 breeding ponds, with a unit yield of 45 kg / m³. 3 The project produced 8,100 kg of marketable fish, generating 1.62 million yuan in fishery income based on a market purchase price of 200 yuan / kg. Sixty hydroponic planting beds were constructed in the planting area, planting approximately 93,600 seedlings of *Acorus calamus*, with an average yield of 1.8 kg per square meter and a total yield of 1,080 kg. *Acorus calamus* roots were sold externally at 70 yuan / kg, generating 75,600 yuan in income. Two reflux wells were also constructed, reducing fertilizer input by approximately 280 kg annually, saving 1,120 yuan in costs. In summary, the total output value reached approximately 1.697 million yuan, with an average output value of approximately 1.379 million yuan per mu.

[0106] Example 2: A recirculating aquaculture system for Murray cod and Acorus calamus, comprising the following steps: (S01) Constructing a 5m high, sunlit greenhouse, within which aquaculture, planting, and recirculation zones are planned, with a planting area to aquaculture area ratio of 4:1. Adjusting the ground height so that the aquaculture zone is 2m higher than the planting zone and the planting zone is 1m higher than the recirculation zone; (S02) Constructing several 20m² aquaculture ponds with a depth of 2.0m in the aquaculture zone, and constructing a 60% shading net above the aquaculture zone; (S03) Constructing several... A hydroponic planting bed with a height of 50cm and an area of ​​21m² is provided. A φ40mm water inlet is set at one corner of the hydroponic planting bed, and a φ40mm overflow outlet is set diagonally opposite the water inlet. The height of the water inlet is 5cm lower than that of the overflow outlet. Coarse ceramic pebbles with a particle size of 20mm are selected, disinfected by soaking in a sodium hypochlorite solution with a concentration of 50ppm, rinsed, and then laid in the hydroponic planting bed as a 30cm layer of ceramic pebbles; (S04) Several return wells with a depth of 2m and a volume of 50m³ are built in the return area. Volcanic rock with a height of 80mm is laid at the bottom of the return wells, and the middle layer is filled with a height of 30mm. Quartz sand, topped with 10mm high biospheres; water is injected into the return well, then active nitrifying bacteria solution with a concentration of 300mL / m³ is inoculated into the return well, and oxygen is supplied to the return well to make the dissolved oxygen concentration in the return well 10mg / L. Aeration and cultivation are carried out for 4 weeks, during which the water quality of the return well is tested every 3 days; (S05) From March to May, 15cm tall *Acorus gramineus* seedlings are selected, and planting holes with a depth of 5cm are set in the expanded clay layer with a plant spacing of 10cm. The roots of the *Acorus gramineus* seedlings are then buried in the holes, and water is injected into the hydroponic planting bed to submerge the roots of the *Acorus gramineus* seedlings. Spray with 80 ppm naphthaleneacetic acid in the evening; (S06) 3-6 months after planting Acorus gramineus seedlings, measure the leaf length of Acorus gramineus, cut off leaves with a length of 40 cm, and retain 7 new leaves. After cutting the leaves, apply 300 ppm humic acid and 0.2% potassium dihydrogen phosphate by foliar spraying in the evening; (S07) From March to May, disinfect the breeding pond with a 2 mg / L chlorine dioxide solution, rinse and fill with water to a depth of 1.5 m, control the water flow rate in the breeding pond to 0.3 m³ / s, and adjust the pH value to 7.5. Supply oxygen to the aquaculture pond to achieve a dissolved oxygen concentration of 10 mg / L and aerate for 48 hours; (S08) Select Murray cod fry of 10-15 cm, soak them in a 5% saline solution for 15 minutes, then put them into plastic bags and place the bags on the surface of the aquaculture pond for 20 minutes. Add 11% pond water to the bags every 6 minutes. After they adapt to the water temperature, remove the bags and release the Murray cod fry into the aquaculture pond at a stocking density of 25 fish / m²; (S09) Select extruded floating feed for California bass containing 48% crude protein and 8% crude fat, and test the water temperature from April to June. When the water temperature is 18-28℃, feed three times a day, with a daily feed amount of 4% of the weight of the Murray cod fry, and replenish 2% of the water daily, performing water circulation 7 times; (S10) From July to September, monitor the water temperature. When the water temperature is 28-32℃, feed twice a day, with a daily feed amount of 3% of the weight of the Murray cod fry. When the water temperature is above 32℃, feed once a day, with a daily feed amount of 1% of the weight of the Murray cod fry, and replenish 4% of the water daily, performing water circulation 10 times; (S11) From October to November, monitor the water temperature. When the water temperature is 18-28℃, feed three times a day, with a daily feed amount of 4% of the weight of the Murray cod fry, and replenish 2% of the water daily, performing water circulation 7 times.

[0107] (S12) Water temperature was monitored from December to March of the following year. When the water temperature was 12-18℃, the fish were fed twice a day at a daily feed amount of 3% of the weight of the Murray cod fry. When the water temperature was 10-12℃, the fish were fed once a day at a daily feed amount of 1% of the weight of the Murray cod fry. No feeding was given when the water temperature was below 10℃. 1% of the water was replenished daily, and the water was circulated 5 times. In this embodiment, 8 breeding ponds (2.0m deep, 20m² / pond) were set up, with a unit yield of 45kg / m³, producing a total of 14,400kg of marketable fish. Based on a market purchase price of 200 yuan / kg, the fishery income reached 2.88 million yuan. 60 hydroponic planting beds (21m² / bed) were constructed in the planting area, planting approximately 126,000 Acorus gramineus seedlings (10cm×10cm spacing), with an average yield of 1.8kg per square meter and a total yield of 2,268kg. Sweet flag root was sold externally at 70 yuan / kg, generating revenue of 158,760 yuan. Two reflux wells (2m deep) were constructed, reducing fertilizer input by approximately 280kg annually and saving 1,120 yuan in costs. Overall, the total output value reached approximately 3.04 million yuan, with an average output value of approximately 1.379 million yuan per mu.

[0108] Example 3: A recirculating aquaculture system for Murray cod and Acorus calamus, comprising the following steps: (S01) Constructing a 5m high, sunlit greenhouse, within which aquaculture, planting, and recirculation zones are planned, with a planting area to aquaculture area ratio of 3.5:1. Adjusting the ground height so that the aquaculture zone is 1.5m higher than the planting zone and the planting zone is 0.65m higher than the recirculation zone; (S02) Constructing several 1.75m deep, 17.5m² aquaculture ponds in the aquaculture zone, and constructing a 55% shading shed above the aquaculture zone using shade netting; (S03) Constructing several 45cm high, 15.5m² hydroponic planting beds in the planting zone, with a φ30mm water inlet at one corner of each bed, and water inlets diagonally positioned... Place a φ30mm overflow outlet, with the inlet height 5cm lower than the overflow outlet. Select coarse ceramsite with a particle size of 15mm, disinfect it by soaking in a sodium hypochlorite solution with a concentration of 35ppm, rinse it, and then lay a 27.5cm layer of ceramsite in the hydroponic planting bed; (S04) Construct several reflux wells with a depth of 1.5m and a volume of 50m³ in the reflux area. Lay a 65mm high layer of volcanic rock at the bottom of the reflux well, fill the middle layer with a 25mm high layer of quartz sand, and cover the top layer with a 7.5mm high layer of biospheres; inject water into the reflux well, then inoculate the reflux well with an active nitrifying bacteria solution with a concentration of 250mL / m³, and supply oxygen to the reflux well to make the dissolved oxygen concentration in the reflux well 8.5mg / L. Aerate and cultivate for 3 weeks, and test the water quality of the reflux well every 3 days during this period;

[0109] (S05) From March to May, select 12.5cm tall Acorus calamus seedlings and plant them in 4cm deep holes in the expanded clay pebbles layer with a spacing of 9cm between plants. Then, bury the roots of the seedlings in the holes, fill the hydroponic planting bed with water to submerge the roots, and spray with 65ppm naphthaleneacetic acid in the evening. (S06) 3-6 months after planting the seedlings, measure the leaf length of the Acorus calamus. Cut off leaves that are 35cm long, leaving 6 new leaves. After cutting the leaves, apply 250ppm humic acid and 0.15% potassium dihydrogen phosphate by foliar spraying in the evening. (S07) From March to May, the aquaculture ponds were disinfected with a 1.5 mg / L chlorine dioxide solution. After rinsing, water was added to a depth of 1.35 m, and the water flow rate was controlled at 0.25 m³ / s. The pH was adjusted to 7.15, and oxygen was supplied to the ponds to achieve a dissolved oxygen concentration of 8.5 mg / L. The ponds were aerated for 36 hours. (S08) Murray cod fry of 10–15 cm were selected and soaked in a 4% saline solution for 12.5 minutes. Then, the fry were placed in plastic bags and floated on the surface of the aquaculture pond for 17.5 minutes. Every 5 minutes, 10% by volume of chlorine dioxide solution was added to the plastic bags. After the water temperature has been adjusted, remove the plastic bag and release the Murray cod fry into the rearing pond at a stocking density of 20 fry / m². (S09) Select extruded floating feed for California bass containing 48% crude protein and 8% crude fat. Monitor the water temperature from April to June. When the water temperature is 18-28℃, feed three times a day, with a daily feed amount of 3.5% of the Murray cod fry's body weight. Add 2% water daily and perform water circulation seven times. (S10) Monitor the water temperature from July to September. When the water temperature is 28-32℃, feed twice a day, with a daily feed amount of 2.5% of the Murray cod fry's body weight. When the water temperature is above 32℃, feed once a day, with a daily feed amount of... (S11) During October and November, monitor the water temperature. When the water temperature is between 18 and 28°C, feed the fish fry three times a day, with a daily feed amount of 3.5% of the fish fry's body weight. Add 2% of the water daily and perform water circulation seven times. (S12) From December to March of the following year, monitor the water temperature. When the water temperature is between 12 and 18°C, feed the fish fry twice a day, with a daily feed amount of 2.5% of the fish fry's body weight. When the water temperature is between 10 and 12°C, feed the fish fry once a day, with a daily feed amount of 1% of the fish fry's body weight. Do not feed the fish when the water temperature is below 10°C. Add 1% of the water daily and perform water circulation five times. This embodiment sets up 8 aquaculture ponds (1.75m deep, 17.5m² / pond), with a unit yield of 45kg / m³, producing a total of 11,025kg of marketable fish. Based on the market purchase price of 200 yuan / kg, the fishery income reaches 2.205 million yuan.The planting area consisted of 60 hydroponic beds (15.5 m² / bed), planting approximately 114,400 Acorus calamus seedlings (9 cm × 9 cm spacing), with an average yield of 1.8 kg per square meter and a total yield of 1,674 kg. Acorus calamus roots were sold externally at 70 yuan / kg, generating revenue of 117,180 yuan. Two return wells (1.5 m deep) were also constructed, reducing fertilizer input by approximately 280 kg annually, saving 1,120 yuan in costs. Overall, the total output value reached approximately 2,323,300 yuan, with an average output value of approximately 1,363,000 yuan per mu.

[0110] During the aquaculture process, water quality data for aquaculture water is monitored, such as... Figure 13 As shown, during the optimal growth period (maximum metabolism) of fish, the water quality monitoring system in the "Murray cod + Acorus calamus" aquaculture area showed that the total nitrogen (TN), ammonia nitrogen (NH3-N), nitrite (NH2-N), and total phosphorus (TP) at the inlet of the aquaculture area were reduced by more than 30%, 20%, 20%, and 40%, respectively, compared to the outlet of the aquaculture area. The pH could be stabilized between 7.0 and 8.0, and the system could also achieve zero discharge of tailwater. After the aquaculture, the survival rate of Murray cod could reach 99.8%, and the application of pesticides and fertilizers for fruits and vegetables could be reduced by more than half.

[0111] The Murray cod-Acorus calamus recirculating aquaculture system includes a breeding area 100, a planting area 200, and a return flow area 300. The breeding area 100 contains several breeding ponds 101, and each breeding pond 101 contains... Figure 2 The aeration component 400 shown is installed in the middle of the aquaculture pond 101. Figure 3 The manure removal assembly 500 shown has several hydroponic planting beds 201 inside the planting area 200, and several other types of hydroponic planting beds 201 inside the return flow area 300. Figure 7 The reflux well 301 shown has a feature on one side as described above. Figure 9The fish screening assembly 600 shown has a first drain pipe 102 between the aquaculture pond 101 and the hydroponic planting bed 201, and a second drain pipe 202 between the hydroponic planting bed 201 and the return well 301. A circulation pump 302 is installed on one side of the return well 301, with an inlet pipe 3021 connected to the end of the circulation pump 302 near the return well 301, and an outlet pipe 3022 connected to the end of the circulation pump 302 near the aquaculture pond 101. The aeration assembly 400 includes a fixing plate 401, which is detachably connected to the side of the aquaculture pond 101. A fixing cylinder 402 is detachably connected to the end of the fixing plate 401 away from the aquaculture pond 101. A drive motor 403 is installed inside the fixing cylinder 402, and an aeration shaft 404 is installed below the drive motor 403. An aeration umbrella 405 is installed at the bottom end of the aeration shaft 404, and the output end of the drive motor 403 is detachably connected to the aeration umbrella 405. The bottom of the breeding pond 101 is provided with a manure outlet 103. A manure outlet 104 is connected to the side of the manure outlet 103 away from the breeding pond 101. The end of the manure outlet 104 away from the manure outlet 103 is connected to the return well 301. A first filter plate 303 is provided on the side of the return well 301 near the manure outlet 103. A second filter plate 304 is provided on one side of the first filter plate 303. A third filter plate 305 is provided on one side of the second filter plate 304.

[0112] The sewage discharge assembly 500 includes a mounting bracket 501. A transmission gear 502 is rotatably connected to one side of the mounting bracket 501. A transmission chain 503 is meshed with the side of the transmission gear 502. A hook 5031 is provided at the bottom end of the transmission chain 503. A drive gear 504 is meshed with the side of the transmission chain 503 away from the transmission gear 502. A driven gear 5041 is provided below the drive gear 504 and meshes with the transmission chain 503. The drive gear 504 is rotatably connected to the mounting bracket 501. A transmission turntable 5042 is rotatably connected to the side of the bracket 501 away from the drive gear 504. The rotation shaft of the transmission turntable 5042 is fixedly connected to the drive gear 504. A drive belt 5043 is meshed with the side of the transmission turntable 5042. A drive turntable 5044 is meshed with the side of the drive belt 5043 away from the transmission turntable 5042. A stepper motor 5045 is arranged on one side of the drive turntable 5044. The output end of the stepper motor 5045 is fixedly connected to the drive turntable 5044. A component such as... is fixedly connected below the stepper motor 5045. Figure 4 The frame 505 is shown. One side of the frame 505 is rotatably connected to a... Figure 5The side baffle 5051 shown has a bottom baffle 5052 below it. The bottom baffle 5052 is rotatably connected to the frame 505. A first bevel gear 50511 is fixedly connected to the bottom end of the rotating shaft of the side baffle 5051. A second bevel gear 50521 is fixedly connected to the side of the rotating shaft of the bottom baffle 5052. The first bevel gear 50511 and the second bevel gear 50521 mesh with each other. A movable plate 50522 is fixedly connected to the middle of the rotating shaft of the bottom baffle 5052. A spring 50523 is fixedly connected to the top of the movable plate 50522. The end of the spring 50523 away from the movable plate 50522 is fixedly connected to the frame 505. A driver 506 is located in the middle of the frame 505, and a drive shaft 507 is located below the driver 506. The output end of the driver 506 is fixedly connected to the drive shaft 507. A propeller 508 is located at the bottom end of the drive shaft 507. A bracket 509 is detachably connected to the bottom of the frame 505. A filter disc 5091 is detachably connected to the inner side of the bracket 509, and a filter plate 5091 is detachably connected to the outer side of the bracket 509. Figure 6 The water-proof ring shown is 5092.

[0113] The fish screening assembly 600 includes a diversion box 601, which is disposed on the side of the return well 301. One side of the diversion box 601 is detachably connected to a... Figure 9The fish inlet trough 602 shown has a first limiting ring 603 on one side, which is connected to the diversion box 601. A main rotating ring 604 is rotatably connected to the inner side of the first limiting ring 603. A first tubular screen 6041 is fixedly connected to the side of the main rotating ring 604 away from the fish inlet trough 602. A first slave rotating ring 6042 is detachably connected to the end of the first tubular screen 6041 away from the main rotating ring 604. The outer side of the first slave rotating ring 6042 is rotatably connected to... A second limiting ring 6031 is connected to the diversion box 601. A second tubular screen 6043 is detachably connected to the side of the first rotating ring 6042 away from the first tubular screen 6041. A second rotating ring 6044 is detachably connected to the end of the second tubular screen 6043 away from the first rotating ring 6042. A third limiting ring 6032 is rotatably connected to the outer side of the second rotating ring 6044. The third limiting ring 6032 is connected to the diversion box 601. A drive belt 605 is engaged with the side of the main rotating ring 604. A driven pulley 6051 is engaged with the end of the drive belt 605 away from the main rotating ring 604. A drive column 6052 is fixedly connected to one side of the driven pulley 6051. The side of the drive column 6052 is rotatably connected to the distributor box 601. A main rotating pulley 6053 is fixedly connected with the end of the drive column 6052 away from the driven pulley 6051. A synchronous belt 6054 is engaged with the side of the main rotating pulley 6053. A servo motor 6055 is engaged with the end of the synchronous belt 6054 away from the main rotating pulley 6053. A filter tank 606 is located below the first limiting ring 603. A screen 6061 is located at the bottom of the filter tank 606. A fish sieve 607 is located on the side of the filter tank 606. A fish outlet 608 is located on the side of the fish sieve 607 away from the filter tank 606. A spiral filter 609 is located below the filter tank 606. An infusion tube 6092 is detachably connected to the top of the spiral filter 609. A motor 6091 is located on the side of the spiral filter 609. The output end of the motor 6091 is fixedly connected to the spiral filter 609. An inlet 6093 is located at the top of the spiral filter 609. An outlet 6094 is located at the bottom of the spiral filter 609. A collection tank 6095 is located below the outlet 6094. A sieve plate 6096 is located on the side of the collection tank 6095. A sieve plate 6096 is located on the side of the sieve plate 6096 away from the collection tank 6095. Figure 10 The water storage tank 6097 shown has a pumping pipe 6098 installed on one side, a water pump 6099 installed on one side of the pumping pipe 6098, and a water delivery pipe 60910 installed above the water pump 6099. The top of the water delivery pipe 60910 is equipped with a... Figure 11 The sprinkler shown is 60911.

Claims

1. The Murray cod-Acorus calamus recirculating aquaculture system with symbiotic fish medicine, characterized by: Including the following step, (S01) Construct a solar-type greenhouse, and plan a breeding area, a planting area and a return flow area inside the greenhouse; (S02) Several breeding ponds are built in the breeding area of ​​step (S01), and an adjustable sunshade canopy is built above the breeding area using shade netting. (S03) Several hydroponic planting beds are built in the planting area of ​​step (S01). The hydroponic planting beds are equipped with water inlets and overflow outlets. The height of the water inlets is lower than that of the overflow outlets. (S04) Several return wells are built in the return zone of step (S01). Volcanic rock layer, quartz sand layer and biosphere layer are laid in the return well from bottom to top, and water is injected into the return well. (S05) Select sweet flag seedlings and bury them in the hydroponic planting bed of step (S03), fill the water to submerge the roots of the sweet flag seedlings, and spray with naphthaleneacetic acid; (S06) After the seedlings of Acorus calamus in step (S05) have grown for a period of time, some leaves are cut off and humic acid and potassium dihydrogen phosphate are sprayed on them. (S07) After disinfecting the aquaculture pond in step (S02), add water, adjust the pH of the water, supply oxygen to the aquaculture pond, and aerate it. (S08) Select Murray cod fry and put them into the culture pond of step (S07) for culture.

2. The recirculating aquaculture system for Murray cod and Acorus calamus fish according to claim 1, characterized in that: In step (S01), the area of ​​the planting area is larger than the area of ​​the breeding area; in step (S01), the ground height of the breeding area is higher than the ground height of the planting area; and the ground height of the planting area is higher than the ground height of the reflux area.

3. The recirculating aquaculture system for Murray cod and Acorus calamus fish as described in claim 1, characterized in that: In step (S03), a layer of expanded clay pebbles is laid in the hydroponic planting bed; The ceramsite layer is prepared by selecting coarse ceramsite with a particle size of 10-20 mm, disinfecting it by soaking it in a sodium hypochlorite solution with a concentration of 20-50 ppm, and then rinsing it.

4. The recirculating aquaculture system for Murray cod and Acorus calamus fish as described in claim 1, characterized in that: In step (S04), active nitrifying bacteria solution is inoculated into the water of the return well, and oxygen is supplied to the return well for aeration and cultivation, controlling the dissolved oxygen concentration in the water to be 7 mg / L to 10 mg / L.

5. The recirculating aquaculture system for Murray cod and Acorus calamus fish as described in claim 1, characterized in that: The burying time in step (S05) is from March to May; the seedling height of the selected sweet flag seedlings in step (S05) is 10cm to 15cm; the distance between adjacent sweet flag seedlings in the hydroponic planting bed in step (S05) is 8cm to 10cm; the ceramsite layer of the hydroponic planting bed in step (S05) has several planting holes with a depth of 3cm to 5cm, and the sweet flag seedlings are buried in the planting holes.

6. The recirculating aquaculture system for Murray cod and Acorus calamus symbiotic aquaculture according to claim 1, characterized in that: In step (S06), the growth period of the Acorus calamus seedlings is 3 to 6 months; in step (S06), leaves with a length of 30 cm to 40 cm are cut off; in step (S06), the spraying method is foliar spraying; in step (S06), the spraying time is evening; in step (S06), the concentration of humic acid is 200 ppm to 300 ppm; in step (S06), the concentration of potassium dihydrogen phosphate is 0.1% to 0.2%.

7. The recirculating aquaculture system for Murray cod and Acorus calamus fish as described in claim 1, characterized in that: In step (S08), (S08-1) Select Murray cod fry and soak them in salt water; (S08-2) After soaking in step (S08-1), put the Murray cod fry into plastic bags; (S08-3) Place the plastic bag from step (S08-2) on the surface of the aquaculture pond and let it float. (S08-4) Add pool water into the plastic bag from step (S08-3); (S08-5) The Murray cod fry in the plastic bag from step (S08-4) are put into the breeding pond from step (S07) for breeding.

8. The recirculating aquaculture system for Murray cod and Acorus calamus fish according to claim 1, characterized in that: It also includes steps, (S09) From April to June, extruded floating feed is fed into the aquaculture pond of step (S08), water is added and water circulation is performed; the extruded floating feed contains 45% to 50% crude protein and 5% to 10% crude fat. (S10) From July to September, extruded floating feed is fed into the aquaculture pond of step (S09), water is added and water circulation is performed; (S11) In October and November, extruded floating feed is fed into the aquaculture pond of step (S10), water is added and water circulation is performed; (S12) From December to March of the following year, extruded floating feed is fed into the aquaculture pond of step (S11), water is added and water circulation is performed.

9. The Murray cod-Acorus calamus recirculating aquaculture system with symbiotic fish medicine, characterized by: The system includes a breeding area (100), a planting area (200), and a reflux area (300). The breeding area (100) contains several breeding ponds (101), each equipped with an aeration unit (400). A manure discharge unit (500) is located in the center of each breeding pond (101). The planting area (200) contains several hydroponic planting beds (201). The reflux area (300) contains several reflux wells (301), with a reflux well (301) located on one side. There is a fish sieve assembly (600), a first drain pipe (102) is provided between the breeding pond (101) and the hydroponic planting bed (201), a second drain pipe (202) is provided between the hydroponic planting bed (201) and the return well (301), a circulation pump (302) is provided on one side of the return well (301), an inlet pipe (3021) is connected to one end of the circulation pump (302) near the return well (301), and an outlet pipe (3022) is connected to one end of the circulation pump (302) near the breeding pond (101).

10. The Murray cod-Acorus calamus recirculating aquaculture system for fish medicine symbiosis according to claim 9, characterized in that: The fish screening assembly (600) includes a diversion box (601) disposed on the side of the return well (301). A fish inlet trough (602) is detachably connected to one side of the diversion box (601). A first limiting ring (603) is provided on one side of the fish inlet trough (602), and the first limiting ring (603) is connected to the diversion box (601). A main rotating ring (604) is rotatably connected to the inner side of the first limiting ring (603). A first tubular screen (6041) is fixedly connected to the side of the main rotating ring (604) away from the fish inlet trough (602). The end of the first tubular screen (6041) away from the main rotating ring (604) is detachably connected to... There is a first rotating ring (6042), and a second limiting ring (6031) is rotatably connected to the outer side of the first rotating ring (6042). The second limiting ring (6031) is connected to the diversion box (601). A second tubular screen (6043) is detachably connected to the side of the first rotating ring (6042) away from the first tubular screen (6041). A second rotating ring (6044) is detachably connected to the end of the second tubular screen (6043) away from the first rotating ring (6042). A third limiting ring (6032) is rotatably connected to the outer side of the second rotating ring (6044). The third limiting ring (6032) is connected to the diversion box (601).

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