Aqua-Prazi. A long known safe remedy for fish in treating internal flukes and tapeworms found in the intestines, gills, liver, etc. and is readily absorbed in the blood of the fish for better treatment. Recommended to treat the pond early Spring and late Fall. Flashing or scratching, sores, problem breathing, etc.can be suspect of internal parasites, tapeworms, etc. and the main ingredient, pure praziquantel, has been a long proven remedy for treatment. Does not effect your filter bacteria or plants. Add directly to your pond water. 1 gram treats 100 gallons of pond water, 25 grams treats 2500 gallons, 50 grams treats 5000 gallons, and 100 grams treats 10,000 gallons.