Effectively destroys stubborn blanketweed and other common species of algae in garden ponds including floating and slime algae. Tetra Pond AlgoFin* also prevents further algae growth. *Use algaecides safely. Always read the label and product information before use. Key Features:   Effectively combats blanketweed, floating and slime algae Prevents algae growth Destroys the algae after two to three weeks Incredibly easy to use with precise dosages For use in ornamental ponds with fish, plants and microorganisms *Use algaecides safely. Always read the label and product information before use.