Pool is crystal clear, but along sides, only on deep end, is a hard green scale that is spreading. We have tried hard bristle brushes, underwater preasure wash (like the guy we hired used) and even tried scrubbing it off with chlorine tablets. The scale starts about a foot down from water level and only goes down to where pool starts its slant to the deep part. in other words, its kind of like only on the straight, up and down, sides. We have put, from the local pool store clerk recomendation and water sample, a "metal control" additive in the water and all to no avail. We called the professional pool cleaner that cleaned it the first time (about 400.00 bucks) and he said (and we did) make a "sandwich" by putting in 5lbs of shock, followed by 3lbs of "yellow out" followed by another 5lbs of shock. We have a 23,000 gallon in ground vinyl pool. Needless to say, nothing happened, the scale is still there and growing....HELP!!!
I tried upoading a pic but its not working for some reason. Our pool looks very much like the one in the forum's logo but with the stairs all the way to the beginning of the shallow end wall.