Cleans algae, moss, mold, and mildew growth and the spores that cause re-growth within 30 seconds Cleans wood, paint, concrete, masonry, metal, cloth, and plastic Cleans 200 sq. feet on porous surfaces and up to 600 sq. feet on non-porous surfaces Fast acting, will not stain concrete Non-corrosive to metals when used as directed Cleans algae, moss, mold, and mildew growth and the spores that cause re-growth within 30 seconds. Cleans wood, paint, concrete, masonry, metal, cloth, and plastic. Wont harm plants. Cleans 200-square feet on porous surfaces and up to 600-square feet on non-porous surfaces. Fast acting, will not stain concrete. Non-corrosive to metals when used as directed. Can be used on greenhouses, tree trunks, decks, patios, walks, porches, steps, hot tubs, pools, boats, convertible tops, RVs, tents, patio furniture, patio umbrellas, etc. Sodium hypochlorite (bleach), biodegradable surfactants, trisodium phosphate. Available in 1-gallon.