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Thread: grey stains

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    grey stains

    HI,

    I have these weird grey spots which formed on the side wall of the pool (my pool is very light blue so I can easily see them). one is 1/1.5 inch big, the other are small , more like dots. I tried to brush them off but they don't go away. I just came back from 2 weeks vacation and have now some at the bottom of the pool.Any idea what it can be?






    here are my chem info. I boosted my SWG while away just to make sure I will not get a bad surprise upon my return.
    FC 15
    CC0
    FC 6
    CC 0
    Ph7.4
    TA125
    CH200
    CYA 40 (that just dropped while away, I will readjust to 70)
    Fiberglass 5.5K gal - Pentair Superflo VS - Circupool RJ 30+ - Star Rite PLM 200 -

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    Mod Squad kimkats's Avatar
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    Re: grey stains

    Have you tried rubbing a chlorine tablet on them? How about some crushed up Vit. C tablets? Those are my go to stain tests. BUT those are not like anything I have seen before.......what do they feel like? Can you feel them?

    Kim
    TFP Moderator 33x52 round AG 25,600 gals Sand Filter 1.5hp Pump - 2 Speed, SLAM, Pool School, Recommended Levels, Recommended Chemicals, Pool Math, Chlorine/CYA Chart, TF-100 Test Kit

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    TFP Guide

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    Re: grey stains

    May be cobalt bleeding through the surface. They use it in fiberglass pools and spas. Used to see it alot in the spas years ago, but most spa's are acrylic or some other composite now

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    Re: grey stains

    Quote Originally Posted by kadavis View Post
    May be cobalt bleeding through the surface. They use it in fiberglass pools and spas. Used to see it alot in the spas years ago, but most spa's are acrylic or some other composite now
    After making some research, it looks exactly like cobalt bleeding...and there is apparently no cure for it...
    Fiberglass 5.5K gal - Pentair Superflo VS - Circupool RJ 30+ - Star Rite PLM 200 -

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    TFP Guide

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    Re: grey stains

    https://images-na.ssl-images-amazon....1P4p-iU8IL.jpg, this is the only product developed for this problem

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    Re: grey stains

    thank you Kadavis. I actually made some research and ordered it. it arrived last night. I will try it this weekend. DId you ever use it?
    Fiberglass 5.5K gal - Pentair Superflo VS - Circupool RJ 30+ - Star Rite PLM 200 -

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    Re: grey stains

    misteur G,

    Please let the forum know if that stuff works. Cobalt is not very common but we have seen posts about it several times over the years. It will be nice to know that there is a fix.
    Dave S.
    42k vinyl and concrete pool, 1.5hp pump, 140gpm filter
    TFTestkits , PoolMath , Pool School

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    Re: grey stains

    Quote Originally Posted by duraleigh View Post
    misteur G,

    Please let the forum know if that stuff works. Cobalt is not very common but we have seen posts about it several times over the years. It will be nice to know that there is a fix.
    Will do
    Fiberglass 5.5K gal - Pentair Superflo VS - Circupool RJ 30+ - Star Rite PLM 200 -

  9. Back To Top    #9

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    Re: grey stains

    I haven't done the Cobalt cure yet, but most of the gray stains are gone.. the biggest on was just under the light and it totally disappear. I can find a 3 or 4 on some part of the wall but they are very tinny. this pool is full of surprises...
    Fiberglass 5.5K gal - Pentair Superflo VS - Circupool RJ 30+ - Star Rite PLM 200 -

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