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.