Powerful Treatment for External Parasites in Aquarium and Pond Fish Plantoz Paranill is a specially formulated antiparasitic solution that effectively eliminates a wide range of harmful external parasites from aquarium and pond fish. It is particularly potent against anchor worms, fish lice, fish fleas, and similar ectoparasites that commonly affect freshwater ornamental and pond fish.Rapidly removes parasites such as: Anchor worms (Lernaea sp.), Fish lice (Argulus sp.), Fish fleas, Other harmful external parasites, Helps reduce irritation, skin inflammation, and stress caused by parasitic infestations. Safe when used as directed for most freshwater fish species.