Dark stains on the bottom surface of the pool

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Chris Chambers

Dark stains on the bottom surface of the pool

Postby Chris Chambers » Mon 24 Sep, 2007 11:39

There are dark stains on the bottom surface of my pool. Is it algae? The surface is far from smooth being painted concrete. I presume the paint is a formula especially for pools. Scrubbing with a medium soft brush has no effect. Any suggestions. Hopefully Chris

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Postby mr_clean » Mon 24 Sep, 2007 14:19

it's going to be black algae or a mineral/metal problem. You can try 2 things which will let you know.

1- take a chlorine tab and rub spot with it and then let it sit on top of it for a few hrs, if it starts going away it's black algae and you can get granular treatment for it which sits on top of it after you have scrubbed with a metal wire brush.

2- take a white sock put in 1/2 pound PH decreaser and let it sit on spot for 15mins. if it starts going away its a mineral/metal problem and you can add metal remover 2-bottles to start. You would have to drop PH to 6.5 to 6.8 and scrub every day until gone. Then readjusting PH back to normal.

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