I am extremely pleased with the results of Corte-Clean® composite deck cleaner. I have used it on my ChoiceDek® twice and it is the only product that has ever removed mold and mildew from my deck for more than six months. At first I followed the recommendation of the retail store associate to use a product with oxalic acid. It had no effect on the dark mold spots whatsoever. The next product we used was chlorine bleach based and as soon as it rained all the spots came back. At this point the manufacturer sent me Corte-Clean® and the problem is now under control. The mold has been removed and my deck has been restored to its original condition. I will continue to use your product and clean my deck yearly.