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Thread: CYA Accuracy

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    Join Date
    Jul 2014
    Location
    Charlotte, nc
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    25

    CYA Accuracy

    Using a TF-100 my CYA reads zero. (I can see the black dot when filled completely.)
    But I know it is not zero. I had the local pool company test it twice 2 weeks apart and they have a reading of 30 ppm both times.
    Also my SLAM calculations are jiving at 12 ppm shock level when I add/test; so I am inclined to think pool store is correct.

    I am certain I am following the instructions correctly.
    Could the R-0013 Reagent go bad?
    Does anyone have experience with inaccurate CYA testing using the TF-100?


    FC: 5
    CC: 1
    PH: 7.0
    TA: 80
    CH:100
    CYA: ?
    22,000 vinyl IG 18x36
    Hayward Star Clear II cartridge filter; 100 sq ft
    Pentair 320 chlorinator 3" Tabs
    Pentair 1 HP motor

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    Mod Squad JVTrain's Avatar
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    Feb 2014
    Location
    Central Minnesota
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    5,079

    Re: CYA Accuracy

    In general, pool store testing for CYA is some of the worst. How did they test? Using the Taylor turbidity test or a whiz bang computer system?

    Your CYA is likely not zero but less than 20 if it's clear to the top of the viewing tube.
    Joel - TFP Moderator - Minnesota - **Become a TFP Supporter!** Helpful Links: ABCs of Pool Water Chemistry - SLAM Procedure - Chlorine/CYA Chart
    40x20 Pool: 32K Gallons * Vinyl * Bleach Chlorination * Hayward S270T Sand Filter * Pentair SuperFlo 1 HP * Teledyne/Laars Heater * AquaVac Tigershark * TF-100 w/ SpeedStir
    Isolated Spa - 345 Gallons

  3. Back To Top    #3

    Join Date
    Jul 2014
    Location
    Charlotte, nc
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    Re: CYA Accuracy

    They are using Taylor test products for sure. And your point is noted: But I am 5 days into the SLAM and while it is premature for an OCLT test, my overnight loss is sometimes around 1ppm; and sometimes during sunny days it is less than 2ppm; wouldn't a CYA of 20 be unstable and cause massive loss of FC...especially when at shock levels of 12-14?
    22,000 vinyl IG 18x36
    Hayward Star Clear II cartridge filter; 100 sq ft
    Pentair 320 chlorinator 3" Tabs
    Pentair 1 HP motor

  4. Back To Top    #4

    Join Date
    Aug 2010
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    Dallas, TX
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    Re: CYA Accuracy

    Test to be observed on sunny day with back to the sun. I seriously doubt the pool store is going outside to test.
    Built in 1957 44,000 gallon in-ground, Wet Edge Primera Stone in Sky Blue, Intelliflo VF Pump, 600 lb. Pentair Triton II TR-100 Sand Filter, CircuPool RG 60 Plus SWG, TF-100 test kit
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  5. Back To Top    #5

    In the Industry

    duraleigh's Avatar
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    Apr 2007
    Location
    Sebring, Florida
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    30,084

    Re: CYA Accuracy

    PM me with your name and # and I'll call and help get you fixed up.

    Dave
    Dave S.
    42k vinyl and concrete pool, 1.5hp pump, 140gpm filter
    TFTestkits , PoolMath , Pool School

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