We purchased out home in 2011. The builder had installed brand new Fiberon composite decking that looked stunning, however approximately 7 years later I noticed some of the board were "graying" in the middle, others were more "black" and others were simply a very light brown. When I contacted Fiberon they said it was "tannins" and that I needed to scrub it with a wire brush (they were going to send me). The process was: wash it, dry it, scrub it, wash it again, dry it again. I had to take video and photos. While it temporarily worked on the 10ft. X 10ft. area I did, we have a 15ft. X 110ft. deck, and the 10 X 10 area I scrubbed looks exactly the same as before. Has anyone else had to go through this much trouble to keep their decking looking like new??