API Melafix is an all-natural antibacterial treatment that works to treat infections in fish. Common bacterial infections are open wounds and abrasions, tail rot, eye cloud, and mouth fungus. API Melafix also promotes regrowth of damaged fins and tissue. Product may be used when adding fish to an aquarium particularly to smooth the transition from store to home and if an infection is suspected, but not yet diagnosed. Some fish bought in pet stores are already carrying diseases at the time of purchase, which may be difficult to detect in its early stages. API Melafix will not adversely affect the biological filter, alter the pH, or discolor water. It is safe for use in freshwater, saltwater, and reef aquariums, and in aquariums with live plants. Dose for the recommended amount of time as directed on label, and in accordance with the size of your aquarium.