Fish are fragile creatures and are easily stressed by situations you just cant avoid. Adding new fish, dealing with water quality problems or carrying out a major clean-out can be a big deal for your little fish. Stress makes your fish more susceptible to the disease-causing organisms which naturally occur in every aquarium. Use Disease Away as an insurance against a disease outbreak by keeping disease organisms at an acceptable level. Use for preventing outbreaks of fungal and bacterial infections as well as parasitic infestations in your aquarium. Can also be used to support fish with a suspected viral infection. Do not use with scaleless fish or invertebrates.