Second, why the fish mouth is rotten 1, and the water quality is not good: the fish mouth will rot, usually related to water, and the poor water quality is the main reason for its rotten mouth. In view of this situation, the best way is to change the water regularly, improve the water environment and let the fish recover slowly. There is no fixed period for changing water, and it is usually adjusted according to the speed of water quality deterioration.
2. Excessive temperature difference: As a temperature-changing animal, fish's adaptability to temperature is relatively limited. If the temperature difference between day and night is large, the fish will also be stimulated, causing its mouth to rot. The best way to avoid this situation is to stabilize the water temperature and control the temperature within a certain range with a heating rod.
3, bacterial infection: when fish are infected with bacteria, it will also lead to mouth rot. Usually, as long as you pay attention to changing water, you can inhibit the growth of bacteria, but if you want to completely eliminate bacteria, you need to disinfect what enters the fish tank, so as to ensure the safety of fish.