Robelle 2165-02 3-Month Algaecide for Swimming Pools (2 Pack), 1 Quart Metallic Algaecide (11.8% Chelated Copper) For All Pool Types (Vinyl, Fiberglass, Concrete, Gunite, etc.) Non-Foaming Prevents and Kills Algae 90 day maintenance dose: 16 oz per 10,000 gallons