The tail split of koi fish indicates that it has rotten tail disease. There are many causes of unfinished tail disease, which are usually related to the deterioration of water quality, indicating that water is not changed frequently at ordinary times, which leads to harm to fish health. In addition, frequent water change will also cause unfinished tail, because water quality fluctuation will stimulate fish to some extent, and even cause stress reaction. Therefore, it is necessary to control the frequency of water change at ordinary times, pay attention to maintaining water temperature and avoid fish being frightened.

1. Isolated feeding: After finding that the tail of koi fish is rotten, it must be isolated, because the rotten tail is most easily attacked by other fish, which will not only get better, but also worsen. Moreover, unfinished tail is generally caused by fungi, which is separated from the original water environment and contributes to its recovery.

2, the old three: If the tail of koi is rotten, the initial treatment is the old three. Give it a change of water first, improve some water quality, and also discharge some mold in the water. Secondly, it is necessary to raise the temperature properly, which is very helpful for the recovery of fish. After heating up, salt is needed, and the general concentration is 3/1000 or 5/1000, which can have a therapeutic effect.

3. Drug soaking: If the old three kinds can't be cured well, it means that the condition of unfinished tail is serious. At this time, some sterilization drugs should be given. The most common drug is yellow powder, that is, furacilin. Put 0.2 g into 100 kg of water, and then soak the fish for treatment. The washing time should not be too long.