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Thread: Stains on steps and spa

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    Stains on steps and spa

    Hi all - I'm sure this is a question that's been asked many times, but I figured I would ask again. We have yellowish stains by the water line on the stairs and in the spa, both of which are gray plastic/fiberglass, I'm not exactly sure. We have very hard water in our town, and the water softener does not soften the water that goes to our outside hose - is it possible these are hard water stains? When I had our water tested earlier in the summer they told me it was actually softer than it should be for a swimming pool. Or if that's not what it is, what else could be the cause, and what is our best solution for getting rid of it? I appreciate any help anyone can give!

    20k gallons
    In ground plaster pool
    Pentair C420 filter, Pentair Whisperflow 2hp

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    Mod Squad YippeeSkippy's Avatar
    Join Date
    Jan 2012
    'burbs of Augusta, Georgia

    Re: Stains on steps and spa

    Go get some Vitamin C tablets and hold them against the stain. If this causes the stain to disappear that tells you the stain is a metal stain. Either from your water or from added metals (some algaecides, mineral systems etc)

    As to your having water tested elsewhere- you need your own reliable test kit. That is the only way we recommend testing pools routinely. We recommend either the TF-100 or the Taylor's K2006, both available from
    My Amazon Smile for November12K Fiberglass IG, Infinity 4000 automatic cover, SWCG, Hayward Sand Filter, Hayward 1.5 Pump, Doheny Discovery Robot, Savi Melody LED pool lights, outdoor speakers and other assorted doo-dads. Sundance Altamar Hot Tub.
    Our pool build--> Our Pool Solved Our Sloping Yard Skippy's Cheap Pool Cooler -->Skippy's New Fountain

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