Precise regulation and control method for breeding water quality of largemouth bass

Abstract

The invention relates to the technical field of aquaculture, in particular to an accurate regulation and control method for micropterus salmoides culture water quality. According to the micropterus salmoides culture water quality regulation and control method, a culture water body meets one or more of the following conditions: (1) adding photosynthetic bacteria into the culture water body every day, and controlling the final concentration of the photosynthetic bacteria in the water body to be 10 < 6 >-10 < 7 > CFU / mL; (2) adjusting the content of dissolved oxygen in the culture water body to 5.5-7.5 mg / L; (3) adjusting the temperature of the culture water to 26 + / -1 DEG C in the daytime and 23 + / -1 DEG C at night. The total nitrogen, total organic carbon and chemical oxygen demand can be obviously reduced through day and night temperature regulation and addition of photosynthetic bacteria, the water change demand is reduced, and the eutrophication risk is reduced; meanwhile, the specific growth rate (SGR) and the weight growth rate (WGH) are improved, the immune and antioxidant indexes are optimized, and the aeration energy consumption is reduced by controlling dissolved oxygen to be 7.0 mg / L.

Description

Technical Field

[0001] This invention relates to the field of aquaculture technology, and in particular to a method for precise control of water quality in largemouth bass farming. Background Technology

[0002] Largemouth bass, an important and high-quality aquaculture species in my country, is increasingly being farmed in high-density, intensive farming models due to its rapid growth, delicious meat, and strong market demand. However, in high-density farming, water quality management becomes a crucial factor determining the success or failure of the farming, directly affecting the fish's growth rate, health status, and economic benefits.

[0003] Currently, water quality control for largemouth bass aquaculture mainly follows conventional static management models. Existing publicly available largemouth bass water quality management strategies primarily employ a "static threshold management" model, specifically: Wide range of water temperature control: Current technology indicates that the suitable water temperature range for largemouth bass to grow is 20~30℃. In practice, in order to prevent stress to the fish, farmers usually tend to maintain the water temperature at a constant value within this range (such as a constant temperature of 25℃ or 26℃), or allow the water temperature to change slowly with the seasons. There is a lack of active diurnal temperature regulation mechanism. Long-term constant temperature can easily lead to a monotonous metabolic level in the fish and cause immune fatigue.

[0004] Single dissolved oxygen limit control: Current technology emphasizes that dissolved oxygen (DO) should be maintained above 4 mg / L, which is regarded as the "safe bottom line" for ensuring survival. In intensive aquaculture practice, in order to be on the safe side, high dissolved oxygen (>8.0 mg / L) is often blindly pursued, resulting in excessive energy consumption; without establishing the optimal dissolved oxygen balance point for the synergistic effect of fish metabolism and photosynthetic bacteria, problems such as suppressed bacterial activity, restricted fish growth, or excessive aeration energy consumption are likely to occur.

[0005] Uncoupled microbial regulation: Although existing technologies mention the use of photosynthetic bacteria and Bacillus to purify water, they are only used as an auxiliary means of addition, and the synergistic coupling relationship between the high colonization concentration of photosynthetic bacteria (PSB) and specific dissolved oxygen and specific water temperature rhythms is not clear.

[0006] Multi-factor regulation is isolated from each other: temperature, dissolved oxygen, and microbial agents are used independently and in combination, without revealing the synergistic coupling mechanism between diurnal temperature variation, specific dissolved oxygen and photosynthetic bacteria colonization, making it difficult to achieve simultaneous improvement in water quality purification and fish health.

[0007] Poor long-term water quality stability: It has limited effectiveness in controlling pollutants such as total nitrogen, ammonia nitrogen, and COD. In the later stages of aquaculture, problems such as water acidification, increased TDS, and water quality deterioration are likely to occur, making it unable to meet the needs of high-density, long-cycle aquaculture.

[0008] In summary, current water quality control technologies for largemouth bass farming remain at the stage of extensive management focused on ensuring survival, making it difficult to simultaneously achieve the synergistic goals of water quality stability, growth performance, immune enhancement, and energy conservation. There is an urgent need for a precise water quality control method for largemouth bass farming that couples temperature rhythms, accurate dissolved oxygen, and efficient microorganisms. Summary of the Invention

[0009] The purpose of this invention is to provide a precise method for controlling the water quality in largemouth bass farming, so as to solve the problems existing in the prior art.

[0010] To achieve the above-mentioned objectives, the present invention provides the following technical solution: This invention provides a method for controlling the water quality in largemouth bass aquaculture, wherein the aquaculture water body meets one or more of the following conditions: (1) Add photosynthetic bacteria to the aquaculture water daily to maintain the final concentration of photosynthetic bacteria in the water at 10. 6 ~10 7 CFU / mL; (2) Adjust the dissolved oxygen content of the aquaculture water to 5.5~7.5 mg / L; (3) Adjust the temperature of the aquaculture water to 26±1℃ during the day and 23±1℃ at night.

[0011] Preferably, the dissolved oxygen content of the aquaculture water is adjusted to 6.5~7 mg / L.

[0012] More preferably, the dissolved oxygen content in the aquaculture water is adjusted to 6.8~7.2 mg / L.

[0013] Preferably, the daytime refers to 8:00 to 20:00; the nighttime refers to 20:00 to 8:00 the next day.

[0014] Preferably, the light intensity of the aquaculture water body also needs to be controlled, with the light intensity on the water surface controlled at 20±3 lx during the day and 400±3 lx at night.

[0015] Preferably, the photosynthetic bacteria is *Rhodopseudomonas palustris* (…). Rhodopseudomonas palustris ).

[0016] Compared with the prior art, the present invention has the following beneficial effects: 1. Improved water quality stability: Diurnal temperature regulation and the addition of photosynthetic bacteria can significantly reduce total nitrogen (TN), total organic carbon (TOC) and chemical oxygen demand (COD), reduce the need for water exchange, and reduce the risk of eutrophication.

[0017] 2. Win-win for growth and health: Temperature regulation and the addition of photosynthetic bacteria can improve specific growth rate (SGR) and weight gain rate (WGH), optimize immune and antioxidant indicators, and overcome the imbalance between growth and health.

[0018] 3. Energy consumption optimization: Dissolved oxygen is controlled at 7.0 mg / L to reduce aeration energy consumption, and temperature control simulates natural changes to adapt to high-density aquaculture and support the application of large-scale aquaculture technology. Attached Figure Description

[0019] Figure 1 To investigate the dynamic changes of water quality parameters in aquaculture water under different management measures during a 42-day experimental period, (A) represents total phosphorus (TP) concentration; (B) represents total nitrogen (TN) concentration; and (C) represents nitrite (NO). 2- (A) is the concentration of ammonia nitrogen (NH3-N); (D) is the conductivity (EC); (E) is the concentration of ammonia nitrogen (NH3-N); (F) is the ultraviolet absorbance at 254 nm (UV). 254 ( ), representing the content of aromatic organic compounds; (G) is the total organic carbon (TOC) concentration; (H) is the total dissolved solids (TDS) concentration; (I) is the chemical oxygen demand (COD); and (J) is the pH value.

[0020] Figure 2 To illustrate the effects of different water management practices on the growth performance of largemouth bass, the data are presented in the form of a violin plot, showing the distribution and probability density of the data; where (A) represents the weight gain rate (WG%); (B) represents the specific growth rate (SGR%); (C) represents the hepatic body index (HSI%); and (D) represents the conditional factor (CF%).

[0021] Figure 3 To investigate the effects of different water resource management measures on the physiological and biochemical indicators of largemouth bass, data from different treatment groups are presented in the form of bar charts (mean ± SEM); where (A) is superoxide dismutase (SOD) activity; (B) is glutathione (GSH) content; (C) is malondialdehyde (MDA) content; (D) is total protein content; (E) is globulin content; (F) is triglyceride content; (G) is total cholesterol content; (H) is supplemented C3 content; and (I) is lysozyme activity. Detailed Implementation

[0022] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0023] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0024] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0025] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be obvious to those skilled in the art. This application specification and embodiments are merely exemplary.

[0026] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0027] All raw materials used in this invention can be obtained commercially or prepared using existing technologies.

[0028] This invention provides a method for controlling the water quality in largemouth bass aquaculture, wherein the aquaculture water body meets one or more of the following conditions: (1) Add photosynthetic bacteria to the aquaculture water daily to maintain the final concentration of photosynthetic bacteria in the water at 10. 6 ~10 7 CFU / mL; (2) Adjust the dissolved oxygen content of the aquaculture water to 5.5~7.5 mg / L; (3) Adjust the temperature of the aquaculture water to 26±1℃ during the day and 23±1℃ at night.

[0029] In this invention, photosynthetic bacteria (PSB) are added to the aquaculture water daily to maintain a final PSB concentration of 10. 6 ~10 7 CFU / mL, continuously exerting its water purification effect.

[0030] Photosynthetic bacteria (PSB) absorb organic matter and nitrogen sources from water through photosynthesis, promoting nitrogen conversion and removal, thereby effectively reducing the concentration of total nitrogen (TN), ammonia nitrogen (NH3-N), and organic matter (such as total organic carbon TOC) in the water. This improves the water purification capacity and maintains the long-term stability of aquaculture water.

[0031] In this invention, dissolved oxygen (DO) in the water is precisely controlled using an aeration device to ensure it is around 7.0 mg / L, rather than the high dissolved oxygen (>8.0 mg / L) found in traditional methods, thus avoiding the energy waste caused by excessive dissolved oxygen. Simultaneously, the risk of growth inhibition due to lower dissolved oxygen (3.0~5.0 mg / L) is also avoided. By controlling dissolved oxygen within a suitable range, aquaculture growth and energy consumption can be balanced, improving the health of largemouth bass and optimizing growth performance.

[0032] In this invention, the water temperature is controlled to simulate natural changes, with a daytime temperature of 26±1℃ and a nighttime temperature of 23±1℃.

[0033] By regulating natural diurnal temperature variations (e.g., 26°C during the day and 23°C at night), the growth performance and health of largemouth bass were significantly improved. Higher daytime temperatures promoted metabolism and appetite, increasing specific growth rate (SGR) and weight gain rate (WGH), while lower nighttime temperatures helped with recovery and reduced stress. This temperature fluctuation regulation enhanced the fish's immunity and antioxidant capacity, and significantly improved lysozyme activity, indicating that the temperature group improved growth while also strengthening health management. Overall, the temperature group ensured synergistic optimization of growth and health while meeting the needs of high-density aquaculture. The core of this invention lies in the discovery of the special physiological effect of a "3°C temperature difference pulse"; the regular, small-amplitude (3°C) diurnal temperature variation effectively simulates the natural rhythm, and this "pulse" stimulates the moderate expression of heat shock proteins (HSPs) and the periodic activation of antioxidant enzyme systems (SOD, GSH). Experimental data showed that the lysozyme activity and growth rate of the "26℃ / 23℃ pulse" group were significantly higher than those of the "constant 26℃" and "constant 23℃" groups. This demonstrates that the specific parameter combination produced a synergistic effect of 1+1>2, rather than a simple parameter additive effect.

[0034] In this invention, the dissolved oxygen content of the aquaculture water is adjusted to 6.5~7 mg / L.

[0035] In this invention, the dissolved oxygen content of the aquaculture water is adjusted to 6.8~7.2 mg / L.

[0036] In this invention, daytime refers to 8:00 to 20:00; nighttime refers to 20:00 to 8:00 the next day.

[0037] In this invention, it is also necessary to control the light intensity of the aquaculture water body, wherein the light intensity of the water surface during the day is controlled at 20±3 lx, and the light intensity at night is controlled at 400±3 lx.

[0038] In this invention, the photosynthetic bacteria is *Rhodopseudomonas palustris* (…). Rhodopseudomonas palustris ).

[0039] This invention systematically optimizes water quality through the integrated application of PSB, dissolved oxygen, and water temperature control, ensuring that the concentration of harmful substances and pollutants in the water remains at a low level. Furthermore, by fine-tuning the combination of dissolved oxygen and PSB, it can promote the growth of largemouth bass while simultaneously enhancing its immunity and antioxidant capacity, thereby achieving synergistic optimization of growth and health.

[0040] This invention, while achieving stable water quality and healthy fish, optimizes key parameters (such as dissolved oxygen concentration and temperature control) to avoid excessive energy consumption, reduce the demand for electricity and equipment, save on aquaculture costs, and maintain the sustainability and efficiency of aquaculture. By precisely controlling the mechanism of action of each parameter, it avoids high energy consumption and stress damage caused by unreasonable dissolved oxygen and temperature control.

[0041] The technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0042] In an embodiment of the present invention, the basic experimental conditions for aquaculture are as follows: Aquaculture system: The experiment was conducted in an indoor recirculating aquaculture system. The aquaculture container was a fiberglass tank (47.5cm×45cm×35cm, effective water depth 25cm), equipped with independent inlet and outlet water and microporous aeration devices.

[0043] Experimental water source: Tap water that has undergone 24 hours of aeration to remove residual chlorine.

[0044] Experimental subjects: Largemouth bass juveniles of uniform size and robust physique were selected, temporarily raised and acclimatized for 7 days, and then randomly divided into groups.

[0045] Daily management: The light cycle is set to 12L:12D (08:00-20:00 light). The light intensity is precisely controlled: 20±3 lx for the water surface during the day and 400±3 lx at night. Commercial feed with crude protein ≥45% and crude fat ≥12% is fed at 9:00 and 16:00 every day until the largemouth bass appear satiated. Uneaten food and feces in the tank are cleaned every 2 days, and the water exchange rate is controlled at 1 / 3 every 2 days to ensure that the water temperature / dissolved oxygen fluctuation is ≤0.5℃ / 0.3mg / L.

[0046] Regularly test total nitrogen (TN), ammonia nitrogen (NH3-N), and chemical oxygen demand (COD) in the water (referring to GB / T11894-1989, HJ535-2009, and HJ828-2017 standards, respectively), as well as fish weight gain (WGH), specific growth rate (SGR), lysozyme, globulin, triglycerides, total cholesterol content, immune (complement C3), and antioxidant (GSH) indicators, and dynamically fine-tune the control parameters.

[0047] Example 1 (Temp group) Temperature control: day and night temperature variation pulse mode is adopted.

[0048] Daytime phase (08:00-20:00): Control the water temperature at 26±1℃ (peak enzyme activity period, promoting growth).

[0049] Night phase (20:00-08:00 the next day): Control the water temperature to drop to 23±1℃ (low metabolic recovery period, reduce energy consumption and stress).

[0050] Dissolved oxygen control: Continuous aeration to maintain dissolved oxygen (DO) at 6.8~7.2 mg / L.

[0051] Microorganisms: No photosynthetic bacteria were added (to verify the effect of temperature pulses separately).

[0052] Example 2 (PSB Group) Temperature control: The temperature is kept constant at 26±1℃ for 24 hours a day.

[0053] Dissolved oxygen control: Continuous aeration to maintain dissolved oxygen (DO) at 6.8~7.2 mg / L.

[0054] Microorganisms: Photosynthetic bacteria (PSB) are added daily to maintain a final concentration of 10 in the water. 6 -10 7 CFU / mL.

[0055] Example 3 Temperature control: day and night temperature variation pulse mode is adopted.

[0056] Daytime phase (08:00-20:00): Control the water temperature at 26±1℃ (peak enzyme activity period, promoting growth).

[0057] Night phase (20:00-08:00 the next day): Control the water temperature to drop to 23±1℃ (low metabolic recovery period, reduce energy consumption and stress).

[0058] Dissolved oxygen control: Continuous aeration to maintain dissolved oxygen (DO) at 6.8~7.2 mg / L.

[0059] Microorganisms: Photosynthetic bacteria (PSB) are added daily to maintain a final concentration of 10 in the water. 6 -10 7 CFU / mL.

[0060] Comparative Example 1 (DO Group) Temperature control: The temperature is kept constant at 26±1℃ for 24 hours a day.

[0061] Dissolved oxygen control: Continuous aeration to maintain dissolved oxygen (DO) at 6.8~7.2 mg / L.

[0062] Microorganisms: No photosynthetic bacteria added.

[0063] Comparative Example 2 (control group) Temperature control: The temperature is kept constant at 26±1℃ for 24 hours a day.

[0064] Dissolved oxygen control: No mechanical aeration is performed; the water body relies on natural reoxygenation, and the dissolved oxygen (DO) fluctuates between 3.0 and 5.0 mg / L.

[0065] Microorganisms: No photosynthetic bacteria added.

[0066] Comparative Example 3 Temperature control: The temperature is kept constant at 23±1℃ for 24 hours a day.

[0067] Dissolved oxygen control: Continuous aeration to maintain dissolved oxygen (DO) at 6.8~7.2 mg / L.

[0068] Microorganisms: No photosynthetic bacteria added.

[0069] Results of the breeding experiment: Figure 1 The experiment investigated the dynamic changes in water quality parameters in aquaculture water under different management measures during a 42-day experimental period. Figure 1 It was found that during the 42-day experiment, compared with the traditional constant-temperature aeration group (Control), the three experimental groups (PSB, DO, and Temp) all showed reduced concentrations of total nitrogen (TN), chemical oxygen demand (COD), and total organic carbon (TOC). Specifically, the temperature pulse group (Temp group) showed particularly significant results: the TN concentration in the Temp group decreased by 62.01% after 42 days. The COD concentration in the Temp group also decreased significantly, by 62.01%. The TOC concentration also showed a significant decrease, with the Temp group reducing it by 135.63%. The temperature pulse group also proved very effective in controlling total phosphorus (TP). Compared with the control group, the total phosphorus concentration in the Temp group showed a significant improvement during the experiment. This result further demonstrates that temperature pulse regulation has a positive effect on improving water quality, especially in reducing harmful substances in the water.

[0070] In addition, ultraviolet absorbance (UV) 254 The total nitrogen (TN) and pH value changed gradually during the experiment, and the UV... 254 The dissolved oxygen (DO) levels remained low, with the traditional low-DO group showing superior performance. Through these optimization measures, the experimental groups successfully achieved water quality stability throughout the entire aquaculture cycle, maintaining long-term water quality stability.

[0071] Figure 2 This study examines the impact of different water management practices on the growth performance of largemouth bass. Figure 2 It was found that the specific growth rate (SGR) and weight gain rate (WGH) of the temperature group were significantly higher than those of the control group, with SGR increasing by 29.51% and WGH increasing by 41.53%, significantly exceeding the growth levels of the control group. The liver-to-body ratio (HSI) of the PSB group was significantly improved compared to the control group, with a 3.65% decrease in HSI compared to the control group. Although slightly lower, it was still relatively better among the treatment groups. The conditional factor (CF) of the DO group was significantly higher than that of the control group, with a 5.03% increase in CF. This indicates that the DO group improved aquaculture efficiency while maintaining healthy growth. These improvements all meet the growth requirements of high-density aquaculture.

[0072] Figure 3 This study investigated the effects of different water resource management measures on the physiological and biochemical indicators of largemouth bass. Compared with the control group, the experimental groups (PSB, DO, and Temp groups) showed more favorable effects on multiple biochemical indicators. For example, the DO group showed a significant increase in glutathione (GSH) levels, with a 34.13% increase, indicating stronger antioxidant capacity. Lysozyme activity was significantly higher in the PSB and Temp groups than in the control group, indicating that these groups performed excellently in improving disease resistance. This result supports the previously mentioned need to enhance immunity and disease resistance. Simultaneously, the levels of globulin, triglycerides, and total cholesterol in the experimental groups (PSB, DO, and Temp groups) were all significantly higher than in the control group, indicating that these treatments significantly improved the fish's immunity. Complement C3 levels were significantly higher in the DO group than in the control group, further confirming the enhanced immunity in the DO group.

[0073] Detailed analysis of the embodiments and comparative examples: (1) Temperature pulse vs. constant temperature (Example 1 vs. Comparative Example 1): Growth performance: Although Comparative Example 1 (constant temperature 26℃) was within the optimal temperature range for largemouth bass, Example 1 (26℃ / 23℃ pulse) showed significantly higher specific growth rate (SGR) and weight gain (WGH) than Comparative Example 1 (an increase of approximately 29.51%). This demonstrates that the "3℃ diurnal temperature difference" proposed in this invention is not a simple environmental fluctuation, but rather effectively activates the physiological rhythms of the fish, achieving the technical effects of "lower energy consumption (no need to heat to 26℃ at night) and faster growth." Figure 2 ).

[0074] Immune health: The antioxidant enzyme (SOD, GSH) activity and lysozyme content of Example 1 were superior to those of Comparative Example 1, indicating that moderate nighttime chilling helps repair and maintain the body's immune system. Figure 3 ).

[0075] (2) Aeration vs. No aeration (Comparative Example 1 vs. Comparative Example 2): Data shows that although Comparative Example 2 (natural dissolved oxygen) met the survival requirements (>3.0 mg / L), its growth rate and feed conversion rate were much lower than those of the aerated group. This further verifies the necessity of locking dissolved oxygen at around 7.0 mg / L in this invention, that is, finding the optimal balance between "survival" and "high yield". Figure 2 ).

[0076] (3) Adding PSB vs. not adding PSB (Example 2 vs. Comparative Example 1): Under the same constant temperature aeration conditions, the peak values ​​of ammonia nitrogen (NH3-N) and nitrite in the water of Example 2 (with added PSB) were significantly lower than those of Comparative Example 1. Figure 1 Furthermore, the fish has a healthier liver-to-body ratio (HSI). Figure 3 This verifies the purification and liver-protecting functions of the probiotic preparation under specific dissolved oxygen conditions.

[0077] Conclusion: This invention clarifies the synergistic mechanism between PSB and dissolved oxygen (such as the synergistic effect of PSB reducing nitrogen and moderate dissolved oxygen activating the HIF-1α pathway), eliminating the need to pursue high dissolved oxygen (>8.0 mg / L), and controlling dissolved oxygen at around 7.0 mg / L (referencing the DO group) to reduce aeration energy consumption; setting simulated natural temperature fluctuations of 26℃ to 23℃ at night further reduces body energy consumption; the technical solution is suitable for high-density aquaculture scenarios (the PSB group showed the best synergistic effect in "water quality-health-growth"), providing support for the sustainability and large-scale promotion of largemouth bass farming.

[0078] In summary, by setting specific diurnal temperature pulses (26℃ / 23℃), combined with precise dissolved oxygen (7.0mg / L) and photosynthetic bacteria colonization, this invention can significantly improve the growth rate and immunity of largemouth bass, while effectively reducing nighttime heating energy consumption.

[0079] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for controlling water quality in largemouth bass farming, characterized in that, Aquaculture water bodies must meet one or more of the following conditions: (1) Add photosynthetic bacteria to the aquaculture water daily to maintain the final concentration of photosynthetic bacteria in the water at 10. 6 ~10 7 CFU / mL; (2) Adjust the dissolved oxygen content of the aquaculture water to 5.5~7.5 mg / L; (3) Adjust the temperature of the aquaculture water to 26±1℃ during the day and 23±1℃ at night.

2. The method for controlling water quality in largemouth bass farming according to claim 1, characterized in that, The dissolved oxygen content in the aquaculture water should be adjusted to 6.5~7 mg / L.

3. The method for controlling water quality in largemouth bass farming according to claim 1, characterized in that, The dissolved oxygen content in the aquaculture water was adjusted to 6.8~7.2 mg / L.

4. The method for controlling water quality in largemouth bass farming according to claim 1, characterized in that, The daytime refers to 8:00 to 20:00; the nighttime refers to 20:00 to 8:00 the next day.

5. The method for controlling water quality in largemouth bass farming according to claim 1, characterized in that, It is also necessary to control the light intensity of the aquaculture water body. During the day, the light intensity on the water surface should be controlled at 20±3 lx, and at night, the light intensity should be controlled at 400±3 lx.

6. The method for controlling water quality in largemouth bass farming according to claim 1, characterized in that, The photosynthetic bacteria are *Rhodopseudomonas palustris* (…). Rhodopseudomonas palustris ).

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