Goldfish Disease #4: Fungal Infection
Your goldfish may develop fungal infections if water quality is poor. Fungal diseases can also affect goldfish that are already sick from other common goldfish diseases.
Causes of Fungus – Stress and a lowered immune system will prompt fungus to grow. Goldfish suffering from parasitic infections, ulcers, or open wounds have a higher chance of also becoming infected with a secondary fungal disease.
Fungal Disease Symptoms – Cotton-like growths along the body and fins are sure signs of a fungal infection. Fungal infections can be fatal if given enough time, as it will spread and attack other areas on the goldfish.
Fungal Disease Treatment – As mentioned earlier, move infected goldfish to a hospital tank before treatment. Fungal diseases are not contagious. Take out the active carbon from the filter and treat the aquarium with Methylene Blue. Methylene Blue works great on sensitive fish and can be very effective when combined with aquarium salt to help your goldfish rebuild their slime coats.
Fungal infections should clear up after a couple of weeks, as long as you continue to keep the aquarium water healthy. Feel free to move your goldfish back to the main aquarium once all signs of fungus have disappeared.