Too much fish excrement in fish tank harmful. Fish excrement will be decomposed by microorganisms in the fish tank, and a substance called ammonia nitrogen will be produced after decomposition, which is toxic to fish. Moreover, after a large number of microorganisms multiply, the water will turn white and foggy, which will also affect the ornamental value. If you want to prevent too much fish excrement in the tank, you can reduce the feeding density or the feeding amount. When changing water at ordinary times, you can clean it properly.

1. Biological cleaning: Biological cleaning is usually used to clean up fish excrement, that is, raising some black-shell shrimps or snails, which will clean up fish excrement. However, it should be noted that black-shell shrimps often become food for some fish, and polyculture has certain risks, and snails must choose soda snails, otherwise they will multiply and explode in the tank.

2. Change water to clean up: You can also clean up fish excrement when changing water at ordinary times. Because it is necessary to pump water first when changing water, pumping water can start from the bottom of the fish tank. As long as there is no bottom sand, all the fish excrement at the bottom of the tank can be pumped away, thus achieving the cleaning effect. Then, new water is slowly added from the tank wall to complete the water change.

3. Filter and clean up: Filter also has the ability to clean up fish excrement. The water flow can bring the fish excrement into the filter box, so that the fish excrement can't be seen, and then the fish excrement will be decomposed, and the ammonia nitrogen produced will be transformed by nitrifying bacteria, so that the water body can be kept clean and hygienic.