API AlgaeFix for Marine AquariumsAlgaefix Marine controls a wide variety of algae types in marine (saltwater) aquariums, and is EPA registered as reef safe. It will not harm marine fish, corals or other invertebrates while eliminating algae growth and keeping your tank clean and clear. Safe, effective algaecide for saltwater fish tanks Controls many types of algae in marine and reef aquariums Will not harm marine fish, corals or other invertebrates When used as directed, Algaefix