Tropical Fish Site

Profiles Reviews Guides for Tropical and Marine

Fungus Fish Disease

Fish who develop fungus are already in a vulnerable state, the result of other serious health problems or attacks, such as parasites, a physical injury or a bacterial infection.


  • Initially, you’ll notice a gray or whitish growth in and on the skin and/or fins
  • Untreated fungus resembles a cottony growth
  • Eventually, as fungus continues to eat away at the fish’s body, the fish will die


Many bacterial infections are misdiagnosed as fungal, so common medications include both a fungicide and antibiotics. Remove activated carbon and conduct partial water changes in between treatments. Treat using protozin as the best route to recovery of a fungal infection.


Due to fungus attacking fish in a venerable state it is always best to ensure the fish are not stressed out and are given the right environment to be living in and correct tank mates. If a very placid fish is introduced to a tank with aggressive fish them it will be very susceptible to getting fungus fish disease. Take a look at the tropical fish profiles to see which fish are compatible with others.

Tropical Fish Site takes no responsibility for diagnosing the exact problem with your tropical fish, this is purely meant as a guide only. Be sure to look at other common tropical fish diseases to ensure you have made the correct diagnosis as there is often crossover between them.