There are several fish in my family (koi fish, Japanese). The weather is cold these days, and one of them is in a bad mood. He doesn't eat or move much. What should I do?

The key to raising fish well is filtration, and the key to filtration is to filter fish feces. Toxins in water are all produced by fish feces. Only by removing ammonia from fish feces can water remain non-toxic, stable and clear, and fish can be healthy and less sick. Due to the lack of attachment area of nitrifying bacteria in bare tanks, there are few nitrifying bacteria, so fish feces can not be treated in time, the ammonia content in water is high, fish are prone to anorexia, water is also prone to turbidity, and green algae appear. It will be helpful to know about Baidu Yongqing filter.