Novel filtering device and fish tank

Abstract

The novel filtering device comprises a right-side tank body, a middle tank body and a left-side tank body which are divided by partition plates, a water inlet is formed in the bottom of the right-side tank body, and the top of the right-side tank body controls the height of an upper communication opening through a liftable water level adjusting piece to achieve dynamic hydraulic retention time adjustment; filter units with positioning structures are stacked in the middle tank body, and a lower communication port is formed in the bottom of a partition plate between the middle tank body and the left tank body; the left tank body integrates a water pump and a water spray nozzle to form a circulation path and increase the dissolved oxygen content of the water body. The fish tank comprises a tank body and a vertical notch formed in the top end of the tank body and used for intercepting floating foam on the water surface, and the novel filtering device is arranged on one side of the tank body. According to the utility model, through the design of modularized quick release, dynamic water level control, accurate positioning, floating foam interception and the like, the problems of complicated maintenance, insufficient filtration, poor load adaptability and the like of a traditional filtering device are solved, high-efficiency and low-maintenance water quality management is realized, and the water quality management device is suitable for aquaculture and fish tank scenes.

Description

Technical Field

[0001] This utility model relates to the field of aquaculture tools, and in particular to a novel filtration device and fish tank. Background Technology

[0002] In aquaculture water treatment technology, the structural design of filtration devices directly affects water purification efficiency and ease of operation and maintenance. Traditional filtration equipment generally adopts an integrated filter chamber structure at the physical filtration level, filling the filter media into a fixed cavity. When it is necessary to replace some filter media or clean a specific filter layer, the entire filter module must be disassembled. This operation not only causes a large-scale shedding of nitrifying bacteria, affecting the stability of the biological system for water purification, but also causes the sealing structure to age and leak due to frequent disassembly and reassembly. In addition, the filter media in traditional filter chambers are usually mixed, such as white cotton, bio-cotton, and ceramic rings stacked together. When replacing a certain layer of filter media, the entire filter media must be emptied out, which is not only time-consuming and labor-intensive, but also easily causes cross-contamination of different functional filter media, disrupting the balance of the entire filtration system.

[0003] Secondly, regarding the hydraulic control of biological filtration, most existing devices regulate water levels through overflow outlets at a fixed height, a method with significant shortcomings. The fixed overflow outlet height is typically designed for low-load scenarios in the early stages of aquaculture. However, during the high-feeding phase of the rearing period, the concentration of suspended solids and ammonia nitrogen in the water increases sharply. The fixed overflow outlet causes water to overflow before it has fully passed through the filtration layer, leading to the accumulation of harmful substances such as nitrite. Furthermore, it cannot adjust the hydraulic retention time of the filtration system in real time according to actual needs such as changes in feed intake and fluctuations in fish excrement load throughout the aquaculture cycle. This results in excessively fast water flow and insufficient filtration during high-load periods, while during low-load periods, there is a problem of wasted energy from water flow.

[0004] Furthermore, while commercially available stacked filter cartridges have a modular design, they rely solely on gravity for stacking and lack precise positioning mechanisms. In actual use, water flow impact can easily cause misalignment of the cartridges, creating unfiltered "short-circuit water flow" and significantly reducing the filter media contact efficiency.

[0005] Therefore, existing filtration devices and aquariums need further optimization and improvement. Utility Model Content

[0006] The purpose of this invention is to provide a new type of filter device and aquarium with dynamic water level adjustment capability, modular quick-release structure and embedded foam interception function, so as to achieve high-efficiency and low-maintenance water quality management.

[0007] To achieve the above objectives, the present invention adopts the following solution: a novel filtration device, comprising a right side tank, a middle tank, and a left side tank arranged sequentially from right to left, wherein the right side tank, the middle tank, and the left side tank are separated into independent cavities by two parallel vertical partitions.

[0008] The bottom of the right tank is provided with a water inlet, and the top of the partition between the right tank and the middle tank is provided with an upper connecting port consisting of a liftable water level regulating component.

[0009] Multiple filter units are stacked from bottom to top in the middle tank. Each filter unit includes a layer box with through holes at the top and bottom. Adjacent layer boxes are interlocked and stacked together by positioning structures set at the four corners.

[0010] The partition between the middle tank and the left tank has a lower connecting port at its lower part;

[0011] A water pump is installed at the bottom of the left side tank, and the water pump sends water back to the aquaculture water body through a water delivery pipe.

[0012] Traditional filtration systems suffer from several significant drawbacks. For example, integrated filter chambers are complex to assemble and disassemble and can easily disrupt nitrifying bacteria communities; stacked filter boxes lack positioning structures and are prone to misalignment; and fixed overflow ports prevent dynamic adjustment of hydraulic retention time. To address these issues, this solution divides the filtration system into three main parts: a right tank, a middle tank, and a left tank, separated by partitions. This modular design allows each tank to serve a specific function, facilitating disassembly, assembly, and maintenance.

[0013] Secondly, a height-adjustable water level regulator was introduced. This design solves the problem that traditional fixed overflow outlets cannot adapt to changes in aquaculture load. With this regulator, we can adjust the water flow rate in real time according to the degree of water pollution. This ensures sufficient filtration under high load and avoids energy waste under low load.

[0014] Next is the stacked positioning filter unit. This solution adopts a modular layer box and positioning structure, which can realize independent layer filling and quick disassembly of filter media. This not only avoids the time-consuming and labor-intensive problem and cross-contamination caused by emptying the entire filter media when replacing it, but also prevents the layer box from being misaligned due to water flow impact, thus preventing the problem of "short-circuit water flow" and improving the contact efficiency of the filter media.

[0015] Finally, a lower connecting port is installed at the bottom of the partition between the middle tank and the left tank, forcing water to flow through all the filter media layers before entering the left tank, ensuring thorough filtration. A water pump is integrated into the left tank, forming a complete water circulation system that continuously maintains water purification.

[0016] The new filtration device proposed in this solution can more effectively solve the problems of traditional filtration devices, providing a more efficient, reliable, and easy-to-maintain solution.

[0017] As a further embodiment of this invention, the top of the filter box is provided with a detachable cover plate. The cover plate has snap-fit ​​fasteners around its perimeter that engage with the snap-fit ​​holes on the four walls of the filter box, forming a water filtration channel between the cover plate and the bottom wall of the filter box, allowing for the filling of filter media. This solution addresses the problem of traditional filter media filling chambers being fixed and requiring complete disassembly and emptying for replacement. By employing a detachable cover plate and snap-fit ​​structure, individual filter boxes can be quickly opened and closed, allowing for the replacement or cleaning of specific filter media layers without disassembling the entire filter module. This reduces the shedding of nitrifying bacteria due to frequent disassembly and assembly, improves maintenance efficiency, and maintains the stability of the biological system.

[0018] As a further embodiment of this utility model, the positioning structure includes grooves at the four corners of the bottom of the layer box, and a supporting top post at the corresponding groove position on the bottom surface of the middle groove body. The supporting top post can be inserted into the groove at the bottom of the upper layer box. The top of the cover plate of the stacked layer boxes is provided with a positioning boss that can be inserted into the groove at the bottom of the upper layer box. This solution addresses the problem that traditional stacked filter boxes rely solely on gravity for stacking and are prone to misalignment due to water flow impact. It adopts a multi-level positioning structure formed by grooves, supporting top posts, and positioning bosses. From bottom support to interlayer insertion, it achieves precise alignment of the layer boxes in all directions, enhances the stability of the stacked layer boxes, effectively prevents misalignment or "short-circuit water flow" caused by water flow impact, ensures that water flow must pass through all filter media layers, and significantly improves the filter media contact area and filtration efficiency.

[0019] As a further embodiment of this invention, the water level regulating component includes a jacket, which is movably clamped in an inverted U-shape at the top of the partition between the right side tank and the middle tank. A guide plate inclined towards the middle tank is connected to one side of the top of the jacket. This solution addresses the problem of the inability to dynamically adjust the height of the traditional fixed overflow outlet by employing an inverted U-shaped jacket design, allowing the water level regulating component to be flexibly raised and lowered. The guide plate guides the water flow smoothly into the middle tank. Operators can adjust the height of the upper outlet in real time according to actual needs such as feed intake and fish excrement load during the aquaculture cycle, precisely controlling the water residence time in the filter media layer. This avoids insufficient filtration due to excessively fast water flow under high load, or wasted energy under low load, thus improving the adaptability of the filtration system to different water quality loads.

[0020] As a further embodiment of this invention, a padding layer is provided between the inner wall of the jacket and the outer wall of the partition, and several anti-slip strips are spaced apart on the contact surface between the padding layer and the outer wall of the partition. This solution addresses the problem that traditional adjustment structures are prone to positional displacement due to water flow impact or operational force. By utilizing the padding layer and anti-slip strips to increase the friction between the jacket and the partition, the water level adjustment component is stably fixed at the set height, preventing slippage due to water flow impact or human contact. This ensures the accuracy and reliability of dynamic water level adjustment and maintains the stability of the hydraulic control of the filtration system.

[0021] As a further embodiment of this utility model, the outer vertical wall of the jacket away from the guide plate is provided with several anti-slip textures at intervals, which enhances the grip of the operator when manually raising and lowering the jacket, facilitates precise control of the adjustment range, reduces operating errors, and makes dynamic water level adjustment more convenient, efficient and accurate.

[0022] As a further embodiment of this invention, the top of the lower connecting port is lower than the bottom surface of the lowest layer of the intermediate tank. If the lower connecting port is too high, water may flow out directly without passing through the bottom layer of filter media. Therefore, the top of the lower connecting port is set to be lower than the bottom surface of the lowest layer of filter media to ensure that the filter media at the bottom of the intermediate tank is completely submerged in water. Water must pass through all the filter media in the layers before flowing into the left tank through the lower connecting port, avoiding filtration blind spots, ensuring the effective utilization of all layers of filter media, and improving the sufficiency and uniformity of the overall filtration effect.

[0023] Traditional aquarium filtration devices suffer from low integration, occupy significant space within the tank, and have insufficient filtration efficiency. Therefore, this invention provides an aquarium solution comprising a tank body for holding aquaculture water and the novel filtration device described above. The novel filtration device is located on one side of the outer wall of the tank body, with the inlet connected to the inner cavity of the tank body and the outlet of the water supply pipe connected to the inner cavity of the tank body. This solution externally positions the novel filtration device on one side of the outer wall of the tank body, achieving a closed-loop water circulation between the tank body and the novel filtration device through the inlet and water supply pipe. This saves space within the tank, ensures a continuous flow of water through the filtration system, improves the continuity and stability of water purification, and the external structure facilitates maintenance and operation without affecting the viewing experience within the tank.

[0024] To address the problems of traditional aquariums, such as a single water circulation path, weak water flow impact, and insufficient dissolved oxygen, this invention provides a further solution by installing a spray nozzle on the outer wall between the tank body and the left side tank, with the nozzle facing the inner cavity of the tank. The outlet end of the water supply pipe is connected to the inlet end of the spray nozzle. In this solution, the spray nozzle returns the filtered water to the tank body in a jetting manner. The disturbance generated by the water jet increases the contact area between the water and air, thereby increasing the dissolved oxygen content in the water. Simultaneously, it optimizes the water circulation path, ensuring that the purified water is more evenly distributed within the tank, avoiding dead zones, and enhancing the uniformity and effectiveness of water purification.

[0025] To address the problem of traditional aquariums lacking foam interception capabilities and allowing surface oil or floating debris to easily enter the filtration system and affect water quality, this invention, in its preferred embodiment, features multiple vertical notches along the top edge of the tank corresponding to the central tank. The bottom of each notch opening is flush with the water surface. These notches are designed to intercept surface foam or floating debris as water flows into the central tank, trapping it within the tank. This design utilizes water level differences to guide water into the central tank. Simultaneously, the flush design of the notch openings with the water surface prevents surface foam from entering the filtration device due to buoyancy, forcing it to remain within the tank. This facilitates centralized cleaning by aquarists, achieving an embedded foam interception function, reducing foam contamination of the filter media, and improving water cleanliness and the stability of the filtration system.

[0026] In summary, the advantages of this utility model compared to the prior art are as follows: This utility model forms a modular quick-release structure by using the positioning and insertion between the layers and the detachable cover of each layer, which solves the problems of cumbersome replacement of traditional filter media, cross-contamination, and shedding of nitrifying bacteria. Maintenance does not require disassembling the entire filter unit, thus improving the stability of the biological system.

[0027] Secondly, a water level regulating component consisting of a liftable jacket and a guide plate is installed at the upper connecting port before the water enters the intermediate tank. By dynamically adjusting the water level regulating component, the hydraulic retention time can be controlled in real time to adapt to changes in the aquaculture load. This avoids insufficient filtration under high load and prevents energy waste under low load.

[0028] Furthermore, the grooves, supporting pillars, and positioning protrusions form a multi-level, precise positioning structure, effectively preventing the filter media from shifting due to water flow impact, thus avoiding "short-circuit water flow." This design ensures that the filter media can fully contact the water flow, improving filtration efficiency.

[0029] Finally, in terms of the tank design, this invention not only effectively separates floating objects on the water surface and reduces filter media contamination through the embedded foam interception design formed by the vertical notch, but also sends the filtered water back to the tank in the form of a spray nozzle, optimizing the water circulation path of the aquarium and improving dissolved oxygen and water quality uniformity.

[0030] In summary, this utility model achieves the water quality management goals of high-efficiency filtration, low maintenance costs, dynamic load adaptation, and active foam interception through its modular quick-release structure, dynamic water level adjustment components, multi-level precise positioning structure, and foam interception and optimized water circulation design. These designs significantly improve the stability, ease of operation and maintenance, and water purification effect of the filtration system. Attached Figure Description

[0031] Figure 1 This is one of the three-dimensional views of this utility model.

[0032] Figure 2 This is the second perspective view of the present invention.

[0033] Figure 3 This is one of the cross-sectional views of the present invention, as well as a schematic diagram of the water flow path and an enlarged view of the water level regulating component when it is not raised.

[0034] Figure 4 This is a second cross-sectional view of the present invention, and an enlarged view of the water level regulating component when it is raised.

[0035] Figure 5 This is the third cross-sectional view of the present invention.

[0036] Figure 6 for Figure 5 Enlarged view of point A in the middle.

[0037] Figure 7 This is an exploded view of the present invention.

[0038] Figure 8 for Figure 7 Enlarged view of point B in the middle.

[0039] Explanation of reference numerals in the attached drawings: 1. Right side tank; 2. Middle tank; 3. Left side tank; 4. Baffle; 5. Water level regulating component; 6. Filter unit; 7. Positioning structure; 8. Cylinder; 9. Vertical notch; 11. Water inlet; 31. Water pump; 32. Water supply pipe; 33. Spray nozzle; 41. Upper connecting port; 42. Lower connecting port; 51. Jacket; 52. Pad layer; 53. Anti-slip strip; 54. Guide plate; 55. Anti-slip texture; 60. Buckle; 61. Layer box; 62. Cover plate; 63. Water filtration channel; 65. Clip hole; 71. Groove; 72. Support top column; 73. Positioning boss. Detailed Implementation

[0040] The following detailed description provides various embodiments or examples for implementing this utility model. Of course, these are merely embodiments or examples and are not intended to be limiting. Additionally, repeated reference numerals, such as repeated numbers and / or letters, may be used in different embodiments. These repetitions are for the purpose of simple and clear description of the invention and do not represent a specific relationship between the different embodiments and / or structures discussed.

[0041] Furthermore, spatial terms may be used, such as "below," "lower," "from the inside out," "above," "upper," and similar terms. These relational terms are used to facilitate the description of the relationship between some elements or features in the drawings and other elements or features. These spatial relational terms include different orientations of the device in use or operation, as well as the orientations described in the drawings. The device may be rotated 90 degrees or otherwise to different orientations, and the spatially related adjectives used therein can be interpreted in the same way. Therefore, they should not be construed as limiting the invention. The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature.

[0042] The present invention will be further described below with reference to the accompanying drawings and specific embodiments: Figures 1 to 8 The illustration shows a novel filtration device and aquarium. The aquarium includes a tank body 8 for holding aquaculture water. The novel filtration device includes a right side tank 1, a middle tank 2, and a left side tank 3 arranged sequentially from right to left along the side wall of the tank body 8. These three tanks are separated into independent cavities by two parallel vertical partitions 4. The bottom of the right side tank 1 has a water inlet 11, which communicates with the inner cavity of the tank body 8 to introduce the aquaculture water to be filtered. The top of the partition 4 between the right side tank 1 and the middle tank 2 is lower than the top of the partition 4 between the middle tank 2 and the left side tank 3, thus forming an upper connecting port 41 that allows water filling the right side tank 1 to enter the middle tank 2. A water level adjustment component 5 is mounted on the upper connecting port 41, which can be raised and lowered, as shown in Figures 3 and 4. Figure 7 The water level regulating component 5 shown consists of an inverted U-shaped jacket 51 and a guide plate 54. The jacket 51 is movably clamped to the top of the partition 4. A pad 52 with anti-slip strips 53 is provided between the inner wall and the outer wall of the partition 4. The outer wall has anti-slip textures 55. The height of the upper connecting port 41 can be adjusted by manually squeezing the anti-slip textures 55 and pulling up or down or pressing the jacket 51. The guide plate 54 is tilted towards the middle tank 2 to guide the water flow smoothly into the middle tank 2 and avoid vortexes caused by water flow impact. When the aquaculture enters the high load stage, raising the jacket 51 can increase the flow area of ​​the upper connecting port 41, reduce the water flow velocity, and prolong the residence time of the water in the filter media layer. When the load is low, lowering the jacket 51 can accelerate the water flow velocity and reduce energy consumption. The friction between the anti-slip strips 53 and the pad 52 can ensure that the jacket 51 is stably fixed at the set height.

[0043] like Figures 3 to 8As shown, multiple filter units 6 are stacked from bottom to top within the intermediate tank 2. Each filter unit 6 includes a layer box 61 with through holes at the top and bottom. The layer box 61 is detachably connected to the corresponding locking holes 65 on the cover plate 62 via buckles 60 on the upper part of its outer walls, forming an independent water filtration channel 63 space. The water filtration channel 63 can be filled with different functional filter media such as white cotton, biochemical cotton, and ceramic rings in layers. Adjacent layer boxes 61 are precisely stacked in the intermediate tank 2 through positioning structures 7 at the four corners. Specifically, the positioning structure 7 includes grooves 71 at the four corners of the bottom of each layer box 61, and a supporting top post 72 on the bottom surface of the intermediate tank 2. The top of the supporting top post 72 is inserted into the groove 71 of the bottommost layer box 61 to achieve bottom positioning; the bottom grooves 71 of the uppermost layer boxes 61 are inserted into the positioning protrusions 73 on the top of their respective lower cover plates 62 to form a locking between the upper and lower layers. This multi-level positioning structure (supporting top column 72 + groove 71 + positioning boss 73) limits the multiple stacked filter media 61 in all three dimensions, preventing misalignment even under water flow impact and avoiding "short-circuit water flow". When replacing the filter media, simply open the buckle 60 of the target filter media 61 and remove the cover plate 62 to replace the filter media of that layer individually, without disassembling the entire module, reducing the shedding of nitrifying bacteria and avoiding cross-contamination of filter media.

[0044] In addition, such as Figure 3 and Figure 4 as well as Figure 7 As shown, the partition 4 between the middle tank 2 and the left tank 3 has a lower connecting port 42 at its lower part. The top of this port is lower than the bottom surface of the lowest layer box 61 of the middle tank 2, ensuring that water must pass through the water filtration channels 63 of all layers 61 sequentially before flowing into the left tank 3 through the lower connecting port 42. This prevents water from flowing out directly from below the bottom filter media or other gaps instead of through all filter media layers as designed, resulting in insufficient filtration. A water pump 31 is installed at the bottom of the left tank 3. The water pump 31 is connected to the spray nozzle 33 on the outer wall of the aquarium 8 via a water pipe 32 (see Figures 1, 2, and 3). Figure 5 The nozzle 33 faces the inner cavity of the cylinder 8 and sends the filtered water back in the form of a jet. The disturbance generated by the water jet can increase the contact area between the water and the air, increase the dissolved oxygen, and optimize the water circulation path and eliminate dead zones (see the arrow of the water flow path in Figure 3).

[0045] like Figures 1 to 5 as well as Figure 7As shown in the figure, it can be clearly seen that the top edge of the aquarium tank 8 corresponding to the middle tank 2 is provided with multiple vertical notches 9. The bottom of the opening is flush with the water surface of the tank 8. When water flows from the right tank 1 into the middle tank 2 through the upper connecting port 41, the foam on the water surface is intercepted and retained in the tank 8 because the buoyancy is higher than the bottom of the notch. This makes it easy for aquaculture personnel to clean it up by siphon or netting, and prevents the foam from entering the filtration system and contaminating the filter media.

[0046] In summary, the novel filtration device and aquarium in this embodiment achieve high-efficiency filtration, low maintenance costs, and adaptive load changes through modular layered filtration, dynamic water level adjustment, three-dimensional positioning to prevent misalignment, embedded foam interception, and jet aeration. This significantly improves the reliability and convenience of aquaculture water quality management.

[0047] The foregoing has shown and described the basic principles and main features of this utility model, as well as its advantages. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A novel filtration device, characterized in that, It includes a right side trough (1), a middle trough (2) and a left side trough (3) arranged from right to left. The right side trough (1), the middle trough (2) and the left side trough (3) are separated into independent cavities by two parallel vertical partitions (4). The bottom of the right tank (1) is provided with a water inlet (11), and the top of the partition (4) between the right tank (1) and the middle tank (2) is provided with an upper connecting port (41) composed of a liftable water level regulating component (5). Multiple filter units (6) are stacked from bottom to top in the middle tank (2). Each filter unit (6) includes a layer box (61) with through holes at the top and bottom. Adjacent layer boxes (61) are interlocked and stacked together by positioning structures (7) set at the four corners. The partition (4) between the middle trough (2) and the left trough (3) is provided with a lower connecting port (42). A water pump (31) is provided at the bottom of the left side tank (3), and the water pump (31) sends water back to the aquaculture water body through the water pipe (32).

2. The novel filtration device according to claim 1, characterized in that, The top of the layer box (61) is provided with a detachable cover plate (62). The four edges of the cover plate (62) are provided with buckles (60) that are engaged with the buckle holes (65) on the four walls of the layer box (61). A water filtration channel (63) that can be filled with filter media is formed between the cover plate (62) and the bottom wall of the layer box (61).

3. The novel filtration device according to claim 2, characterized in that, The positioning structure (7) includes grooves (71) at the four corners of the bottom of the layer box (61), and a support top post (72) is provided on the bottom surface of the middle groove (2) corresponding to the groove (71) of the layer box (61). The support top post (72) can be inserted into the groove (71) at the bottom of the layer box (61) above it. The top of the cover plate (62) of the stacked layer boxes (61) is provided with positioning bosses (73) that can be inserted into the groove (71) at the bottom of the upper layer box (61).

4. The novel filtration device according to claim 1, characterized in that, The water level regulating component (5) includes a jacket (51), which is in an inverted U-shape and is movably clamped on the top of the partition (4) between the right side tank (1) and the middle tank (2). A guide plate (54) inclined towards the middle tank (2) is connected to one side of the top of the jacket (51).

5. A novel filtration device according to claim 4, characterized in that, A pad (52) is provided between the inner wall of the jacket (51) and the outer wall of the partition (4), and a number of anti-slip strips (53) are provided at intervals on the contact surface between the pad (52) and the outer wall of the partition (4).

6. A novel filtration device according to claim 4, characterized in that, The jacket (51) has several anti-slip patterns (55) spaced apart on the vertical outer wall of the side away from the guide plate (54).

7. A novel filtration device according to claim 3, characterized in that, The top height of the lower connecting port (42) is lower than the bottom height of the bottom layer box (61) of the middle trough (2).

8. A fish tank, characterized in that, The invention includes a tank (8) for holding aquaculture water and a novel filtration device according to any one of claims 1 to 7, wherein the novel filtration device is disposed on one side of the outer wall of the tank (8), the inlet (11) is connected to the inner cavity of the tank (8), and the outlet of the water supply pipe (32) is connected to the inner cavity of the tank (8).

9. A fish tank according to claim 8, characterized in that, A water nozzle (33) with a nozzle facing the inner cavity of the cylinder (8) is provided on the outer wall between the cylinder (8) and the left side tank (3), and the water outlet of the water supply pipe (32) is connected to the water inlet of the water nozzle (33).

10. A fish tank according to claim 8, characterized in that, The cylinder (8) has multiple vertical notches (9) at the top edge of the intermediate tank (2). The bottom of the opening of the vertical notch (9) is flush with the water surface of the cylinder (8). The vertical notch (9) is configured to intercept the foam or floating matter on the water surface and keep it in the cylinder (8) when the water in the cylinder (8) flows into the intermediate tank (2).

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