Superdeck brand products composite deck cleaner is the safe, nontoxic way to clean and remove dirt, grease stains, mold, mildew, and algae from all types of composite decking, vinyl fences, siding, and other synthetic composite surfaces. Composite Deck Cleaner uses a unique Oxygen Bleach Technology combined with active cleaning ingredients which when mixed with water releases oxygen, attacking and breaking down organic stains and dirt. It will not harm plants, grass, or other foliage. Contains no calcium hypochlorite bleach. 2.5 Lb. powder with 2 Oz. scoop provided in container. Mix ratio: Dissolve 4 scoops (8 Oz. or 1 C.) per gallon of warm water in plastic bucket. 1 full 2.5 Lb. container will make 5 gallon of cleaning solution. 1 gallon of solution will clean approximately 150 to 200 Sq. Ft.