Water conditioner containing natural, vegetable tannins. Specifically suited for water treatment in aquariums inhabited by fish requiring slightly acidic and soft water. Biotorfin creates proper conditions of forest biotopes, like South American Blackwater streams. Especially useful for breeding fish such as neon tetra, discus, angelfish, ornate tetra, ram cichlid and many others. Biotorfin is safe in use and recommended also to improve aquarium hygiene as it causes precipitation of protein compounds to the bottom deposit.