Spray & Forget Gallon Ready-to-Use House & Deck Outdoor Cleaner with Nested Trigger Spray. Removes stains caused by algae mold and mildew. This powerful cleaner requires no pre-use mixing. Simply spray and go about your day. Great for use on brick walls fences driveways walkways siding stucco and decks. 1 gallon container can cover 150-200 sq. ft. Follow directions carefully for use. Spray every 24-36 months or at the first sight of new staining. Spray & Forget keeps cleaning long after application. This exterior spray cleaner saves time with no rinsing required.