All-in-one (kills green, mustard and black pool algae). Algae killer. Quick and effective. Extra Blue. Easy. Black. Mustard. Green. Quick & effective – kills pool algae in 24 hours. Green. Mustard. Black. Patented non-foaming formula. For use in all pool types. Pool Types: chlorine; saltwater; bromine; in-ground; above-ground; pop-up. Surfaces: vinyl; plaster; aggregate; gunite; fiberglass; concrete. Filter Types: DE; sand; cartridge; zeolite. Treats up to 25,000 gallons. Dosage (Per 10,000 gal.). 16 fl oz; When/How to Use: To kill green, mustard or black algae: 1. Add a choline shock per use directions and run pump for 1 hour. 2. Add algaecide in areas of heaviest algae growth, operate filter and pump for 24 hours. 3. After 24 hours, brush surfaces. For persistent algae, reapply after 72 hours. 8 fl oz: Preventional/Start-up Dose: add along pool edges for first application while operating filter and pump. 1.5 fl oz; Weekly Prevention: Add weekly while operating filter pump. Effective algaecide that kills all types of pool algae to quickly clean pools. Basic green algae. Stubborn mustard algae. Tough black algae. Most common type. Free-floating, but may form on surfaces. Can tiny water green during blooms. Yellowish dust/slime. Fast-growing. Cling to surfaces. Needs algaecide – since it resists chlorine. Black or green/blue spots. Firmly attaches to surfaces with roots. Forms protective crust. Treats up to 25,000 gallons! For swimming pool use only. Questions? Pool care tips? cloroxpool.com.