this is our second year using Corte Clean to clean our composite deck. and it was much better this year. following the direction and using the maximum ounces per gallon our deck came out 90% better. We were very impressed with how clean it came out. We used a power washer to assist with the rinsing and it saved time. We will be doing it again in the fall since our deck is 14yrs. old. The instructions recommend cleaning the deck twice if it was in bad shape. Our needed some serious cleaning and now that we got it 90% we are shooting for 100% Thanks for making a good product to clean decks.