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Thread: Rising Calcium - Re-Plastered Pool

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    Join Date
    Jun 2013
    Location
    Houston, TX
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    9

    Rising Calcium - Re-Plastered Pool

    My pool was re-plastered on June 14, 2013.

    This morning's test results
    FC 8.5
    pH 7.8
    TA 80
    CH 440
    CYA 50

    I added 42 ounces of acid today. I add about 42 ounces of acid every other day. This lowers the PH from 7.8 to about 7.4-7.3.

    I lose about 2 PPM chlorine in a 24 hour period. The pool is in the shade at least 40% of the day. I add about 51 ounces of bleach each day with the Stenner pump starting at dusk. The bleach says 8.25 but I suspect it is a higher concentration because I get a higher rise in the chlorine level than the pool calculator predicts.

    I have a couple of questions.

    What are the advantages/disadvantages of raising the CL level to 8.5 and letting it go to down 6.5 versus raising the CL level to 6.0 and letting it go down to 4.0. The guidelines for a 50 CYA level are minimum of 4.0 with a target of 6.0. I have been raising it to 8.5/9.0 because I was worried the circulation of the pool would not distribute the chlorine evenly.

    The CH level has been rising. It was about 330 a month ago but is now 440. Is this to be expected with new plaster or am I doing something
    wrong. The pool had an acid startup.
    29.2K Gallon Pool/Spa - Gunite/Diamond Brite
    Houston, TX Built 1983, Replastered June 14, 2013
    2 HP Sta-Rite Pump with replacement 2 speed motor, 60 SF Nautilus DE Filter
    Stenner Pump, No Heater, 280 Polaris
    TF100 Test Kit

  2. Back To Top    #2
    linen's Avatar
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    Jul 2010
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    Twin Cities, MN
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    8,649

    Re: Rising Calcium - Re-Plastered Pool

    Quote Originally Posted by hp223
    What are the advantages/disadvantages of raising the CL level to 8.5 and letting it go to down 6.5 versus raising the CL level to 6.0 and letting it go down to 4.0. The guidelines for a 50 CYA level are minimum of 4.0 with a target of 6.0. I have been raising it to 8.5/9.0 because I was worried the circulation of the pool would not distribute the chlorine evenly.
    As long as your FC stays above the minimum, then the advantage of a lower FC level will be less chlorine usage since less will be lost to the sun. If your pool goes from 6 to 4 ppm FC just due to losses from the sun, then if you go to 8.5 ppm you will drop ~5.5 ppm each day or a net ~ 3ppm verses 2 ppm lost. The advantage to running higher is you have a more margin for error.

    Quote Originally Posted by hp223
    The CH level has been rising. It was about 330 a month ago but is now 440. Is this to be expected with new plaster or am I doing something
    wrong. The pool had an acid startup.
    First, I am not an expert on this....but it is not uncommon for the CH level to rise on new plaster startups. You TA being as low as it is for startup may be part of the reason you CH is going up. Normally a TA of 80 is fine, but with new plaster, my understanding is ideally you may want it higher. My guess is though, you should not be seeing a lot more CH rise at the 2 month point now. Again, I am not an expert on this (I have never maintained new plaster), hopefully one will show up and comment Here is one discussion I have found: http://www.troublefreepool.com/ph-ri...3.html#p325911
    TFP Expert who uses Pool School and my TF100 test kit along with PoolMath for my: Round 11K gallon AGP with deep end, 20" sand filter, Matrix 1hp 2spd, 6 2ftX20ft solar panels (and solar cover!), Intex SWCG (copper bars disconnected) and a Rubadub hot tub (chlorine). The SLAM process is not finished until: 1. CC < 0.5 ppm, 2. An OCLT < 1.0 ppm and, 3. The water is crystal clear.

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    BoDarville's Avatar
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    Jun 2012
    Location
    DFW, Texas
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    Re: Rising Calcium - Re-Plastered Pool

    Yep, a CH rise in a newly-plastered pool is quite normal. The link linen provided goes into more details on this. Here is another article you may want to look at: Start-up New Plaster. One caveat...If your installer has given you specific "start-up" procedures that differ with anything in this article, the installer's instructions take precedence so as to maintain your warranty.
    Gold Supporter, TFP Lifetime Supporter, 26,680 gal Plaster IGP 3.5 - 10' depth / Attached Waterfall Spa, Manually Chlorinated, Triton Sand Filter, 1.5 HP * 1.1 SF = 1.65 SFHP 1-speed Pentair WhisperFlo WF-26 Pump, 400K BTU NG Teledyne Laars Series One Heater, Polaris 360, Test Kit Comparison, Chlorine/CYA Chart, SLAMing Your Pool, OCLT
    A good test kit is an investment, not an expense.

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