How to Treat Fungus on Aquarium Fish

Fungus is always present in fish aquariums. Fungal infections appear as cotton-like growths and are opportunistic. Open cuts or sores on injured fish cause many fungus infections and can spread to other fish in the aquarium. Dirty aquarium water makes infection more likely. Fungal infections can kill fish if they are left untreated.

Things You'll Need

  • Extra fish tank
  • Aquarium heater
  • Aquarium filter
  • Aquarium disinfectant
  • Water dechlorinator
  • Fish net
  • Commercial aquarium fungus treatment
  • Fish food high in vitamin C
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Instructions

    • 1

      Identify all fish that have white, cotton-like growths. Keep a close watch on all the fish in the tank since others may become infected with fungus.

    • 2

      Clean a separate fish tank (to use as a hospital tank), aquarium heater and a simple aquarium filter with aquarium disinfectant and rinse thoroughly, or just rinse and wipe clean with tap water. Fill the tank with water and add dechlorinator.

    • 3

      Fill the aquarium filter with filter mesh from a previous filter that has not been cleaned, or simply rinse dirty filter mesh from another tank in the hospital tank. This will introduce necessary bacteria needed to remove toxins. Do not use a carbon filter because it will remove medication.

    • 4

      Bring the hospital tank water to the exact temperature of the main tank water to reduce stress on the sick fish. Remove the infected fish from the main tank with a net and place them in the hospital tank to reduce the risk of spreading the infection to other fish.

    • 5

      Add a commercial aquarium fungus treatment to the hospital tank. Read the directions carefully for exact measurements to avoid overdosing the water and killing the fish. Most treatments will last a few days to a week.

    • 6

      Feed the fish a diet high in vitamin C. Purchase fish flakes or pellets that contain vitamin C or try peas. Remove uneaten food to prevent pollution in the aquarium water. Add a vitamin supplement to the water if you cannot find a food rich with vitamin C. Use the dosage prescribed on the product label.

    • 7

      Return the fish to the main tank once the treatment is complete and the fish shows no signs of infection.