KOI NITRO nitrofurazone powder is a must-have item for any serious koi keeper. Nitrofurazone is a highly effective treatment for newly arriving fish. Extremely safe, KOI NITRO nitrofurazone powder is ideal for koi, ornamental fish, freshwater and saltwater fish. Not as harsh on weaker fish as other treatments, KOI NITRO pure nitrofurazone powder is also an excellent choice for treating tanks, aquariums and ponds. The professional's choice, KOI NITRO is trusted by respected koi breeders and koi breeders worldwide. Nitrofurazone is an ideal treatment for many common fish ailments including Columnaris, Flexibacter, Bacterial Gill Disease, Aeromonas Bacteria, Mouth, Fin, and Tail Rot. Nitrofurazone is not recommended for use in reef tanks and may leave your water with a slight yellow tint after treatment is completed. This yellow tint will fade over time with water changes.