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Thread: 1st TF-100 Test Data. Recommendations?

  1. Back To Top    #1

    Join Date
    Aug 2007
    SF Peninsula

    1st TF-100 Test Data. Recommendations?

    1) Test results TF-100 drop based test kit include:
    Free Chlorine:27
    Combined chlorine, using an FAS-DPD test: 5 ppm
    (TC: 32ppm
    Total Alkalinity:520
    (Tap Water TA: ~ 130)
    CYA:100 ppm
    Salt" : n/a , no SWG

    2) The gallonage of your pool OR it's shape (rectangle + Grecian Ends) ~30' x ~ 18' x ~5' or est ~20,000 gallons

    3) The finishlaster
    The form of chlorine: was trichlor tabs with occasional 12% poolstore NaOCl, now only Clorox 6% NaOCl.

    4) Whether you use any metal or '"mineral" sanitizers: none

    5) What the water looks like: clear, (plenty of bleach eventually cleared the green algae)

    6) The kind of filter: cartridge

    7) Location: SF Peninsula, California

    Had not understood TriChlor contribution to CYA build-up. Had CYA ~ 200 assuming CA viewtube is approximately
    a log scale. Drained ~ 1/4 pool water to reduce CYA to ~ 100 as listed above. Taylor K-1000 TC goes off-scale
    with redish precipitate; diluted to 50% tap water 50% pool water and TC is 5ppm or more.

    Algae now under control. Thinking I should reduce CYA, but nature will provide 100% fresh rainwater in
    ~ 2 months to dilute/replace pumped out pool water tainted excessive CYA. Too much FC? Still see whisps of algae
    when I brush the pool down, and plenty on/in the cartridge at backwashing.
    30k gallon inground with vinyl liner
    Hayward cartridge filter
    Southcentral PA

  2. Back To Top    #2

    In the Industry

    duraleigh's Avatar
    Join Date
    Apr 2007
    Sebring, Florida

    Re: 1st TF-100 Test Data. Recommendations?


    Don't feel bad about not understanding what the pucks do. It's probably the biggest issue on the forum and the puck folks aren't about to tell you about it.

    Now, if the Combined Chloramines test is correct (5ppm) that's way over the top and you'll need to keep your FC VERY high until you get the CC's down to .5 or less. Do you have a strong chlorine smell around the pool? If so, that's actually the CC's and what you need to get rid of them is, yep, Higher FC over a period of time.

    Next your Alk test results are maybe the highest I have ever seen posted. With a fill water of 130 (fine) do you have any idea how the Alk got so high? I would suggest you start reducing T/A thru the aeration method (post back if you need advice on how) and get the Alk down into a more normal (80-120) range.

    Of course your CYA is too high but you already know that and I understand your thoughts on waiting for the'll help your Alk, too, for that matter.

    If you can keep your FC high enough for the next couple of months, you can probably get by with those very high numbers and then let the rainwater correct/help correct your pool water.

    On a brighter note, it seems you have a good understanding of where you are now and where you eventually need to be. You can get straightend out now with a big partial drain or keep your FC way up 'til the rains come.
    Dave S.
    42k vinyl and concrete pool, 1.5hp pump, 140gpm filter
    TFTestkits , PoolMath , Pool School

  3. Back To Top    #3

    Join Date
    Aug 2007
    SF Peninsula

    Transcription Error, New Results


    Thank you for the helpful reply. After reading your note I realized my error: I transcribed the CH figures into the T/A results.

    Here's a new set of results (just taken tonight)
    Free Chlorine:20 ppm
    Combined chlorine, using an FAS-DPD test: 1 ppm
    (TC: 21ppm
    pH:7.3 (same)
    Total Alkalinity: 80 **** Corrected!
    (Tap Water TA: ~ 130)
    CYA:100 ppm to ~110 ppm

    CH 520 (Result from prior testing)

    With much appreciation for your help,
    30k gallon inground with vinyl liner
    Hayward cartridge filter
    Southcentral PA

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