We’ve had mold stains on our Trex deck since the very first year. I have tried every product out there with little or no luck. I wasn’t happy about Corte-Clean’s price, but I figured I’d give a try. I did a little test area, thinking I’d return it like I’ve returned all the other cleaners I’ve purchased and WOW is all I can say. Can’t wait to clear the furniture and plants off so that I can do the whole deck tonight. Thanks for a great product!