Melafix all natural anti bacterial remedy for fresh and saltwater aquariumsr will not harm the biological filter or color the waterr melafix uses the anti bacterial power of melaleuca the name for a variety of tea tree for the treatment of bacterial infections in fresh and saltwater fishr the healing properties of tea tree extract have been known for centuries and are now available for treating aquarium fishr melafix is so unique that after more than six years of research and development