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Thread: readings with tftestkit

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    readings with tftestkit

    Hi Guys just did all the test's with new test kit. What do you think?

    FC 2.5
    CC .5
    Tc 3.0
    PH 8.2 (always has been on the high side)
    TA 120
    CH 550 (never really got it to turn a blue more purple)
    CYA 40

    any feedback?
    Bosqueboy in Virginia

    In-ground 20,000 gal vinyl Grecian, Hayward Star-Clear Plus C1200 cartridge filter, Hayward 3/4 HP Superpump, AquaRite salt water chlorine generator, Heat Siphon C575HP heat pump and Blue Diamond robotic cleaner.

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    JasonLion's Avatar
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    May 2007
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    Re: readings with tftestkit

    Congratulations on your first test with the new kit!

    You really ought to bring your PH down to something below 7.8, especially given your fairly high CH level. At those levels I would expect some calcium scaling. If you lower TA it will be easier to maintain a reasonable PH level, see Lower Total Alkalinity at Pool School.

    The CH test works best if you swirl a good while between drops. Mixing for at least 20 seconds after each drop does get tedious, but it makes for more precise CH results.
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
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    Guest

    Re: readings with tftestkit

    for very high calcium you can do the test this way:
    use a 10 ml sample (instead of 25 ml)
    Add 10 drops of the first reagent (the calcium bufer)
    add 3 drops of the indicator
    now when you titrate each drop is equivalent to 25 ppm CH instead of 10 ppm calcium hardness. As Jason said, swirling for 20 seconds or so between drops is IMPORTANT!. If you don't you can often get the purple color your describe (called a floating endpoint). Often you also get a much higher CH reading then you actually have!
    While you do lose some precision this way it's not really an issue when you have high calcium levels...after all, when you calcium hardness is over 500 ppm does it really matter if it 's 540 ppm, 550 ppm or 560 ppm? Not really! 25 ppm precision is fine!

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