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Thread: pH test with TF-100

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    pH test with TF-100

    I've been testing my water with my TF-100 for well over a year. Before that I used the same Taylor pH test with the five pH levels (6.8, 7.2, 7.5, 7.8 and 8.2). I probably test for pH every other day and sometimes every day. So I've had a decent amount of practice over the last 18 months since we built the pool. I can clearly tell when the test result is 7.2 or 7.5. But anything above 7.5 is pretty much a guess. Although I've never seen the purple of 8.2, the result has gotten fairly dark red which I assume is around 8.0, but I'm not sure.

    Also, I've tried to guess at 7.4 or 7.6 when the color seems slightly below or above the color of 7.5, but it's really just a guess. I don't believe I'm color blind--at least I've never had an issue before. Any ideas on distinguishing between say 7.7, 7.8, 7.9, 8.0, and 8.1?

    Are they just guesses based on the shade of red you get? My problem is that above 7.5 the results all seem red to me, except some are slightly darker and some are slightly lighter. For CSI purposes there's a big difference between 7.7 and 8.1, but how can you really tell? Does 8.0 have a dark red/purple shade? Again, I don't recall ever seeing a purple tint to my test results.

    This is important to me because maybe my water is leveling off at 7.8 to 7.9 and I just can't tell. Adding about 32 oz. of MA every 4-5 days is getting old.

    Here are my latest test results if interested:

    FC 3.5
    CC 0.0
    pH 7.5 (added MA yesterday morning)
    TA 60
    CH 510
    CYA 70
    Salt 3200
    Borates 50
    CSI -.32 at 88 degrees.
    9,200 gal. Gunite Luna Quartz French Grey pool with spill over spa, two fountains on tanning ledge (rarely used)
    Pentair Whisperflo 2HP, Pentair CCP Cartridge 420 Sq. Ft., Polaris 280 with booster pump
    Pentair EasyTouch 4, RayPak LoNox 266k Natural Gas heater, Aqua Rite SWCG T Cell 9, Borates, TF-100 test kit

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    harleysilo's Avatar
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    Re: pH test with TF-100

    It bugs the heck out of me too. I wish there was a endpoint/color change drop test for PH.
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    Re: pH test with TF-100

    If you hold a white piece of paper behind the test, it is much easier to distinguish the color (at least that's what I do ). Still isn't a perfect system, but it has helped me recently.

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    Re: pH test with TF-100

    Thanks. I do the white paper trick, but it still seems like various slight shades of red to me. As I just posted in an older thread on a similar topic, maybe my pH has maxed out at 7.6 and I just didn't know it. I've never seen a pink or purple shade in my test sample.
    9,200 gal. Gunite Luna Quartz French Grey pool with spill over spa, two fountains on tanning ledge (rarely used)
    Pentair Whisperflo 2HP, Pentair CCP Cartridge 420 Sq. Ft., Polaris 280 with booster pump
    Pentair EasyTouch 4, RayPak LoNox 266k Natural Gas heater, Aqua Rite SWCG T Cell 9, Borates, TF-100 test kit

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    JasonLion's Avatar
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    Re: pH test with TF-100

    You can get some acid demand and/or base demand reagent and use them to change the PH of a sample so you can see the various colors.
    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

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    duraleigh's Avatar
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    Re: pH test with TF-100

    I find this helpful to me...

    above 8.2 purple
    8.0-8.2 purplish red
    7.8 pinkish red with a hint of purple
    7.6 red
    7.4-7.5 red with an orange cast
    7.2 orange
    7.0 yellow orange
    6.8 and below yellow
    Dave S.
    42k vinyl and concrete pool, 1.5hp pump, 140gpm filter
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    Isaac-1's Avatar
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    Re: pH test with TF-100

    I have read that people loose their ability to distinguish shades of purple as they age, and the effect is typically measurable starting around the age of 35. I wonder if this issue many members have with the pH test may be related.
    Indoor 20x40 35,000 gallon vinyl pool with 1.5 HP 2 speed Jandy FloPro pump, Hayward EC75 Perflex DE filter, 11 4x12 Techno-Solis solar panels w/ Aquasolar controller, Aquabot Turbo T Robot Cleaner. Also LMI metering chlorine dispenser pump and HotSpring Jetsetter
    I use and endorse TFtestKits TF-100 from http://tftestkits.net
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    Richard320's Avatar
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    Re: pH test with TF-100

    Besides the white background, try holding the thing at arm's length. That helps me.

    Also, using an extra drop tends to make the color more vivid without changing the reading. Try that, too.
    16K freeform gunite with spa; Pentair 4000 DE filter; Century Whisperflow 1 HP; Pentair Minimax heater.
    Troublefree does not mean Maintenancefree. It's like brushing your teeth: You can spend a couple minutes a day and pennies a week or go to the dentist once a year and spend several thousand dollars.
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