Hi , Im a new member here and have an inground vinyl pool. My problem is green on sides of pool. We had it cleaned professionally, it was great. We did all the chemical process we were told then it started raining . so we shocked more. green still there. Tried scrubbing to no effect. Its lie its there to stay. Next we have had to add water (WELL WATER) shock at least 3 lbs. every other day as was told by pool man. Still green sides. Would it help if I added Metal Control? TYVM Kia

Welcome! We're gonna need a set of test results.

Welcome to TFP.

What does the water look like? Is it clear but tinted? Can you see the bottom? Can you post a pic of it?

It sounds like metal staining and there are procedures for removing it but lets make sure that's what it is before we start.

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.

Take some vitamin C tablets and crush them up and put them in a sock and hold it on a place that's scaled for a little while. If it lightens or removes the stain then you definitely have metal stains. You will probably require an AA treatment to get rid of them all. There's an article in pool school on metal stains and one on the forum on performing the Ascorbic Acid Treatment.

Do you know if you have iron in your well water?

You can use a photo hosting site to load your pics and then link them here using the IMG tags.

ok did the vitamin c test. the stain comes off some. can i use "metal control" says it helps prevent stains scale & cloudy water and if i can how soon before or after adding shock?

You probably need to do an AA treatment and then use one of the sequestrants listed in the article.