I just wanted to let you know this is the third year I have used Corte Clean on our Trex decking and how satisfied my husband and I are with the product. We built our Trex deck and spiral staircase in 2005 and by the spring of 2007 we noticed black spots all over the deck and stairs. I contacted customer service at Trex. I explained to her that all I wanted was a way to get the deck back to its original shape. She told me that on their web site was a way to clean it but that she would send me some information. I received that information along with a claim form but they wanted us to use bleach on our deck. I got on line and found out that many people across the country that had Trex decking were very dissatisfied with the bleach and found that the spots came back even worse. Corte Clean absolutely cleans our deck beautifully! By the time I found your product on the internet, our deck was in pretty bad shape. We had to use the scrub technique to get rid of the spots and in some places had to give it a second treatment. Thanks so much for all your ideas and help!!! Bev C West Liberty, IA