Treats fish lice (Argulus), anchor worm (Lernea), gill maggots (Ergasilus) are just some of the horrific parasites/predators, which can attack fish and are almost invisible to the naked eye. New Parazin destroys these and other insect and crustacean parasites/predators found in aquaria. This is a unique and revolutionary product that usually only requires one dose per infestation. For use in tropical freshwater and coldwater aquaria.