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Thread: Stains on concrete coping

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    Stains on concrete coping

    I have a 17K gallon two year old pool with a SWG.

    Recently, I've been getting white residue on my concrete coping. I'm not sure if it has something to do with the salt, or some other chemical problem. It seems to be coming up from within the concrete. I can wash it off, but it keeps coming back. The coping also seems discolored. I never sealed the concrete, which was a bonehead move.

    I've never managed to get my PH down, but my alkalinity is between 80 to 100.

    Can someone tell me what may be causing this? Is there a way to stop it? Is there a way to clean the coping. Would sealing the concrete help in the future?

    Any help would be much appreciated...
    Grant and Jerri
    Liberty, NC
    New 18x36 vinyl liner pool with lighting and fountain

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    Re: Stains on concrete coping

    A picture of the stain would help a lot.

    Your pH absolutely has to be addressed, regardless of what's causing the stain. Why can't you lower your pH? What is it currently?
    Dave S.
    42k vinyl and concrete pool, 1.5hp pump, 140gpm filter
    TFTestkits , PoolMath , Pool School

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    Re: Stains on concrete coping

    I'm not sure why my PH is high. Currently it's around 8 or 8.2. Please see the picture. Any suggestions or ideas?
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    Grant and Jerri
    Liberty, NC
    New 18x36 vinyl liner pool with lighting and fountain

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    Re: Stains on concrete coping

    That is calcium. It fell out of suspension from the water because the pH was too high. I would bet the walls and floor are starting to show it too. The process is called Calcium scaling.

    Please read Pool School and basic pool chemistry.

    Scott
    Owner of - PoolGuyNJ LLC
    Expert Pool and Spa Repairs, Renovations, and Augmentation. Helping people decide what is the right gear for meeting their needs. Expectations Set, Expectations Met, No Surprises.

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    Re: Stains on concrete coping

    Quote Originally Posted by PoolGuyNJ
    That is calcium. It fell out of suspension from the water because the pH was too high. I would bet the walls and floor are starting to show it too. The process is called Calcium scaling.

    Please read Pool School and basic pool chemistry.

    Scott
    It could be calcium, or salt.

    Calcium, and salt will stay behind when water evaporates no matter what the pH is.

    I'd have your calcium hardness (CH) levels checked, but the only thing you can do to prevent this is frequently rinse the pool decks off (unless you live in a area with really hard water).



    Regardless of the staining you see, you should always manage your pH.
    20X40 30,000 gallon gunite pool

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