The reasons why Luohan fish have parasites:

1. There is no trapped water when changing the water, or the water contains parasite eggs, and the temperature is not controlled properly when changing the water. Excessive temperature difference will lead to parasites in Luohan fish.

2. Due to the hot weather in summer, a large number of bacteria and microorganisms will breed in the water, which will cause the physical condition of Luohan fish to decline. Once there are parasites in the water, they will be easily parasitized.

3. If there is not a good filtration system and the filter cotton is not cleaned frequently, bacteria and parasites will also breed. Luohan fish's resistance is reduced and it is easily infected by parasites.

4. Food. When feeding Luohan fish live food, some fish, shrimps or red worms have a lot of bacteria and parasites on them. If they are not handled properly and fed to Luohan fish, live food can easily carry parasites into the fish.

5. When Luohan fish is mixed with other fish, it will also be easily infected with parasites. Parasites are very contagious, and if there are too many fish mixed in, the possibility of infection will greatly increase.