Treatment: Fish Fungus
Tea-tree oil is sometimes promoted as a less toxic antifungal medication. While it can work up to a point, tea-tree oil medication is inconsistent in effectiveness and may not be strong enough to treat severe fungal infections. Tea-tree oil is best considered as a preventative or precautionary measure — something to be used in situations where the fish are not yet sick, but they could be physically damaged because of fin nipping, fighting or handling.
Salt is not a reliable antifungal medication at the doses suitable for use with most community fish, though raising the salinity will help keep fungal infections at bay in tanks with livebearers and brackish fish. Even so, this therapeutic effect should be viewed within the context of providing these fish with better environmental conditions, in particular their needs for a basic pH, moderate to high levels of hardness and a level of salinity appropriate to the species in question.
