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Thread: chlorine levels and pH reading

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    chlorine levels and pH reading

    I know that high chlorine levels cause the pH reading to be inaccurate.

    Can anyone tell me how high the chlorine is when this starts to happen?

    Thanks,

    Patricia

    17K inground white plaster, hayward pump and filter system jet vac sweep

    TC 8
    pH 7.5
    TA 120
    CH 260
    CYA 45
    17,000 gal IGP, White plaster, Hayward Swimclear Cartridge Filter system, Sta-Rite Max-e-pro 1/2 hp pump; 3/4 hp booster pump

    Sacramento, CA

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    Re: chlorine levels and pH reading

    Above FC = 10 pH readings are not to be acted upon.

    Ok to trust pH below FC = 10
    23,000 gallon in ground pool with rock waterfall and spillover spa, Aqualink control system, Polaris 380 cleaner, Purex Triton Clean&Clear Plus cartridge filter. Located in The Woodlands, Texas.

    Pool owner since Nov 2008, Trouble Free since April 2009. Happy to help when I can.

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    JasonLion's Avatar
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    Re: chlorine levels and pH reading

    To add to what anonapersona said, there is actually some slight error even when FC is below 10, but it isn't considered significant. The error increases as FC continues to rise, until FC gets into the low 20s, and then the PH reading suddenly becomes very dramatically wrong.
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
    Creator of PoolMath and Pool Calculator. Other handy links: Support this site, TF Test Kits, Pool School

  4. Back To Top    #4

    Re: chlorine levels and pH reading

    Thanks. Without really knowing it I have been doing approximately what is implied here - not trusting the pH reading above 8 - 10 ppm.
    17,000 gal IGP, White plaster, Hayward Swimclear Cartridge Filter system, Sta-Rite Max-e-pro 1/2 hp pump; 3/4 hp booster pump

    Sacramento, CA

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