My composit deck was in terrible shape with stains from a wide variety of sources. I followed the recommended directions and what a wonderful surprise. An almost clean deck. After one application the years worth of stains have significantly deminished. I want to follow up with a second cleaning. I believe, from what I have already experienced, that my eight year old deck will look as new as the day I finished building it. I wish I had taken some before and after pictures. Oh well. What I am going to do is order two more bags. Then I will reorder in the fall. Great product! I am a satisfied customer.