Melafix smooths your fishs transition from pet store to your home aquarium by reducing the risk of disease developing, using an all-natural solution to address open wounds, tail rot, eye cloud and more. Melafix will not harmfully affect the biological filter, alter the pH level, or discolour the water of your tank. Its safe for reef aquariums and live plants, and can be used in fresh or salt water aquariums to treat disease in your new fish before it spreads.