KOI PRAZI is the fluke destroyer! Praziquantel, commonly known as prazi, is the safest and most effective treatment for flukes in ponds, water gardens, and aquariums. KOI PRAZI Fluke Destroyer is the freshest and the purest praziquantel powder available on the market. An absolute MUST-HAVE treatment for any serious koi keeper, KOI PRAZI is also trusted and recommended by many top koi breeders, dealers, and importers. Seasonal use of KOI PRAZI can help to maintain optimal koi fish health while preventing koi fish losses caused by fluke outbreaks and resulting bacterial infections. Unlike other pond treatments, KOI PRAZI will not setback your bio-filter so there is no need to bypass your pond filter during treatment. KOI PRAZI is a highly effective treatment for koi, goldfish, marine, and ornamental fish. Use KOI PRAZI every spring to help get your pond fish off to a great season, then use KOI PRAZI again in the fall just before winter arrives. Treat all new fish additions with KOI PRAZI to help avoid introducing opportunistic flukes into your pond. The potent compound used in KOI PRAZI effectively eliminates flukes.