API BETTAFIX fish remedy is an all-natural, antibacterial fish remedy for Bettas that should be used whenever your Betta exhibits signs of disease, such as wounds, ulcers, mouth fungus, fin & tail rot, slimy patches, and cottony growths. BETTAFIX fish remedy aids in healing damaged tissue as a result of handling, netting, and fighting using the healing power of Melaleuca – a variety of Tea Tree oil – which promotes rapid re-growth of damaged fins and skin.