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Thread: Plaster issue

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    Plaster issue

    Had our first pool party of the summer today, albeit a small get together

    The plaster in the pool became quite coarse/rough in several areas, particularly in the attached spa and shallow end.

    What caused this and can it be fixed easily?
    25,000 gallon Concrete/Plaster Pool
    Pentair WFDS-26 - Installed Spring 2012
    Pentair Quad DE 100 - Installed Spring 2012
    Pentair Kreepy Krauly 820 - In Service 05/26/2013
    K-2006 Test kit, Intermatic P1353me Digital Timer, Stenner 85MHP5

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    JasonLion's Avatar
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    Re: Plaster issue

    Off hand, that sounds like calcium scaling, though it could be several other things. Could you post a complete set of water test results and if possible a photo of an affected area?
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
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    Re: Plaster issue

    Quote Originally Posted by JasonLion
    Off hand, that sounds like calcium scaling, though it could be several other things. Could you post a complete set of water test results and if possible a photo of an affected area?
    Yes sir, Ill post first thing in the morning when there is good light to take a photo along with a fresh batch of test results. They should be in line as they were a week ago, but I'll double check in the am.

    That being said, the PH was over 8 when the pool was opened.
    25,000 gallon Concrete/Plaster Pool
    Pentair WFDS-26 - Installed Spring 2012
    Pentair Quad DE 100 - Installed Spring 2012
    Pentair Kreepy Krauly 820 - In Service 05/26/2013
    K-2006 Test kit, Intermatic P1353me Digital Timer, Stenner 85MHP5

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    Re: Plaster issue

    AM Test Results:

    FC: 5.5
    CC: 0.0
    PH: 7.4
    TA: 80 ppm
    CH: 270 ppm
    CYA: 30ish

    The first six pictures are of the spa and shallow end. Excuse the dirt in the spa, its proved rather difficult to clean out effectively. The last 3 pictures are of the steps into the pool and deep end by the drain. Both of those areas have a stain area that isn't related to the roughness of the plaster but I'd like to get those resolved as well.

    Pictures:

















    25,000 gallon Concrete/Plaster Pool
    Pentair WFDS-26 - Installed Spring 2012
    Pentair Quad DE 100 - Installed Spring 2012
    Pentair Kreepy Krauly 820 - In Service 05/26/2013
    K-2006 Test kit, Intermatic P1353me Digital Timer, Stenner 85MHP5

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    Richard320's Avatar
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    Re: Plaster issue

    Looks like this:



    Scale. pH got too high. Scrub it with a steel brush and keep the pH down below 7.4 and it will slowly dissolve. progress-on-scale-t38568.html
    16K freeform gunite with spa; Pentair 4000 DE filter; Century Whisperflow 1 HP; Pentair Minimax heater.
    Troublefree does not mean Maintenancefree. It's like brushing your teeth: You can spend a couple minutes a day and pennies a week or go to the dentist once a year and spend several thousand dollars.
    A pool is like a pet - you have to feed it every day, even the days you don't want to play with it!

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    Re: Plaster issue

    The PH was over 8 when I opened the pool and I imagine was for some time after the pool closed. It was brought down to the appropriate range before closing, but for some reason I had issues with the PH rising quickly last year. I imagine the same thing happened after the pool was closed

    Is your plaster rough to the touch as well?
    25,000 gallon Concrete/Plaster Pool
    Pentair WFDS-26 - Installed Spring 2012
    Pentair Quad DE 100 - Installed Spring 2012
    Pentair Kreepy Krauly 820 - In Service 05/26/2013
    K-2006 Test kit, Intermatic P1353me Digital Timer, Stenner 85MHP5

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    Richard320's Avatar
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    Re: Plaster issue

    Quote Originally Posted by stslimited84
    The PH was over 8 when I opened the pool and I imagine was for some time after the pool closed. It was brought down to the appropriate range before closing, but for some reason I had issues with the PH rising quickly last year. I imagine the same thing happened after the pool was closed

    Is your plaster rough to the touch as well?
    No, it just looks like the pool has eczema. Mine is hardly noticeable in full sunlight, but sunrise and sunset, its very noticeable.

    I have astronomical CH, so I keep pH down below 7.4 and knocked TA down to 50-60. That keeps CSI negative, which is ever so slowly removing it.
    16K freeform gunite with spa; Pentair 4000 DE filter; Century Whisperflow 1 HP; Pentair Minimax heater.
    Troublefree does not mean Maintenancefree. It's like brushing your teeth: You can spend a couple minutes a day and pennies a week or go to the dentist once a year and spend several thousand dollars.
    A pool is like a pet - you have to feed it every day, even the days you don't want to play with it!

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    Re: Plaster issue

    stslimlilted84, I go with JasonLion's opinion. It looks very much like calcium scaling due to high pH over winter time, and the roughness is the confirmation. However, some of the discoloration (as evidence on top step picture) is due to another issue with the plaster, but that occurred back when the plaster was new.

    Since Richard320's pool plaster surface is smooth, it is not likely that the problem is due to calcium scaling. It is more likely a plaster workmanship issue when it was plastered. The plaster surface probably lost some cement material over time and is now more porous than the surrounding areas which results in a contrasting appearance.

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    Re: Plaster issue

    Quote Originally Posted by onBalance
    stslimlilted84, I go with JasonLion's opinion. It looks very much like calcium scaling due to high pH over winter time, and the roughness is the confirmation. However, some of the discoloration (as evidence on top step picture) is due to another issue with the plaster, but that occurred back when the plaster was new.

    Since Richard320's pool plaster surface is smooth, it is not likely that the problem is due to calcium scaling. It is more likely a plaster workmanship issue when it was plastered. The plaster surface probably lost some cement material over time and is now more porous than the surrounding areas which results in a contrasting appearance.

    Just to clarify, you're saying you agree with Jason's opinion of my issue being that of calcium scaling versus Richard's being a different issue? I believe the stain on the step is from the step railing and was going to post later on about how to test this theory.

    Being that it seems calcium scaling is the culprit causing the roughness, do you also recommend Richard's solution of a wire brush and ph below 7.4 to correct the issue (i.e. restore the smooth finish)?
    25,000 gallon Concrete/Plaster Pool
    Pentair WFDS-26 - Installed Spring 2012
    Pentair Quad DE 100 - Installed Spring 2012
    Pentair Kreepy Krauly 820 - In Service 05/26/2013
    K-2006 Test kit, Intermatic P1353me Digital Timer, Stenner 85MHP5

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    Re: Plaster issue

    Yes, Richard's solution will probably work. Since the scaling just occurred over the past winter, it is likely that the scale will come off with stainless steel wire brushing and lowering the pH and TA. But it probably will take a few weeks of doing both.

    I am sorry about not addressing the stain on the step. It looks like something might have scaped the plaster surface and left some marks in the spa(?) and some brown discoloration on step(?). You might try sanding with 100 grit wet & dry sandpaper. That should remove the stain and also smooth up the steps and any other areas you sand.

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