The appropriate water depth for fish culture is about 2-3 meters. Usually, the water for fish farming should not be too shallow, otherwise the water temperature will change as soon as the ambient temperature changes. If the temperature difference is too large, the health of fish will be affected and even stress reaction will occur. Similarly, the water should not be too deep, otherwise the sunlight will not shine on the bottom layer, which will lead to the decrease of dissolved oxygen at the bottom, which is very unfavorable to the overall material circulation.

1. Siniperca chuatsi: Siniperca chuatsi is a freshwater fish, which is more common in rivers, lakes and reservoirs where aquatic plants are flourishing. It will hide under the water during the day and come out for food at night. As a carnivorous fish, it mainly feeds on small fish and other aquatic animals, and has high economic value.

2. Rainbow trout: Rainbow trout is a kind of salmon, which is native to North America. It generally likes to move at the upstream source and has a very lively temperament. It mainly feeds on insects, invertebrates and small fish, and also eats aquatic plants. This kind of fish is delicious in meat and rich in nutrition, so it is also very suitable for breeding.

3. Grass carp: Grass carp is a typical herbivorous fish, which generally inhabits rivers and lakes and likes to move in the middle and lower layers of water bodies. It has a lively temperament, swims very fast, and forages in groups. As one of the four major fishes, it is widely farmed in China.