The long frost on the fish shows that it has water mold. If you want to treat it, you should soak it with furacilin or oxytetracycline in addition to changing water and heating up. This is a common disease, and there are many pathogenic bacteria, among which the most well-known ones are water mold and cotton mold, which invade from the surface of fish, especially the wound, and then slowly grow hyphae, causing some flocs to appear on its surface. Fish are often depressed and have poor appetite after illness, and even threaten their lives in severe cases.

1. Keep high temperature: To prevent water mold, the best way is to keep high water temperature. This disease is generally easy to suffer from when the temperature is low, and high temperature can inhibit the growth and reproduction of mold, so it is not easy to get sick, and it can also accelerate the metabolism of fish, thus being able to expel harmful substances from the body.

2. Avoid injury: Water mold usually invades from fish wounds, so it is also important to avoid injury in daily feeding. Usually, mixed fish must provide enough space, don't let the breeding density be too high, otherwise it is easy to fight, and don't put sharp Stone in the tank to avoid fish injury.

3. Changing water regularly: Changing water regularly is the best way to prevent various diseases. The content of harmful bacteria in water can be reduced by changing water, and some fungi can be eliminated by the stimulation of new water, so it has a very good effect on preventing water mold, but changing water should not be too frequent or too much at one time, so as not to eliminate beneficial bacteria in the tank.