Spray & Forget Gallon, Super Concentrate Revolutionary Roof Cleaner.Gallon, Makes Up To 10 Gallons Of Cleaner/Preventive, Revolutionary Patent Pending Cleaner That Removes Green & Black Algae, Mildew, Fungus & Lichen Stains From Roofs, Siding, Decks, Brick, Stucco & Other Exterior Surfaces, Biodegradable, Non-Corrosive & Does Not Require Damaging Power Washing. Can Be Used In Pump Sprayer. There Is No Rinsing Required & Your Landscaping Will Not Be Compromised, An Eco-Friendly Product That Does Not Contain Any Bleach, Chlorine, Lye & Heavy Metals Or Acids.