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Thread: lowering TA

  1. Back To Top    #1

    Join Date
    Mar 2009
    Location
    Charlotte, NC
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    lowering TA

    Thursday 6/18/2015
    pH7.6 so pH is increasing too much/too fast, about 1.3 ppm/day, so I want to decrease TA to about Target 55 Target by lowering the pH to about 7.2 and then aeration to increase the pH, did a one hour retest and pH was at 7.2
    FC 8 so
    CC 0
    TA 70, decrease TA to Target 55 via 29 oz acid to Target pH7.2 then aerate until pH gets to ph7.5
    CH 225, Target 250 with 59oz oz by volume of calcium chloride
    CYA 30-40 assume 30 Target 45 with by weight or 41oz by volume ; very little rain so frequent tap water addition of about 0.75 inches every 3 days
    borates 0
    85 F
    CSI: balanced only if ph is7.4-7.9 & ^ the CH did not help keep CSI balanced

    Saturday 6/20/2015
    pH equal 7.5 or 7.6, so aeration got pH back in range in about 36 hours
    TA 70, I was hoping it would be lower. The evening of 6/19/20 we got about 1.25 inches of rain, unsure if that is an issue. Also unsure if the additions for CH & CYA had any impact which are no longer indicated today.

    I want to lower my TA. The past 2-3 summers by getting TA in the 50 range there was much less frequent addition of acid, Jason ok'd it (TA50 does not work for me in the winter, only the summer).
    My question is: just want me to hit it again with the acid + aeration? You want me to target pH 7.0 instead of pH7.2?

    All questions and comments appreciated
    19,800 gallons (closed/winter 18,654 gal); plaster; 18x34 Ft kidney bean shape, Depth 3Ft-5Ft. Built 1992
    Pentair Whisper Flow Pump 1HP. Winter safety cover w anchors.
    Sand filter, Pentair Sand Dollar Top Mount Model SD80; Effective Filtration Area 3.5SF
    - FlowRate 75GPM, 8Hr 36,000, 10Hr 45,000, 12Hr 54,000; Pressure Weight 50PSI
    BBB (Hayward Chlorinator when leave town). Polaris 360 cleaner.

  2. Back To Top    #2
    Mod Squad tim5055's Avatar
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    Re: lowering TA

    Acid + aeration and you will get there.
    TFP Moderator 39 X 18 23,000(ish) freeform gunite; built 2007ish; Pentair Triton II TR100 600lb Sand filter; 2 HP Pentair pump with 2.2 HP AO Smith single speed motor; 2 skimmers, 1 main drain, 4 returns w/waterfall, Stenner 45MHP2 3GPD running@ 60% - 15 gal Tank; heated by the sun CYA 200+ when I started - 50 now. Dolphin Supreme M5 Pool Cleaner. Hot Springs SX Spa, 285 gallon

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    Mod Squad pooldv's Avatar
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    Re: lowering TA

    Here is the process for Lowering Total Alkalinity

    Also, adding borates can help stabilize TA. More here, Borates - Why and How
    TFP Moderator
    If TFP helped you or saved you money - Become a TFP Supporter! <--Click here
    2012 build and pics, 20k gal gunite, black onyx pebblesheen, OK flagstone, IntellifoVS, cart filter w/Pleatco, IC40 SWG, Solartouch, 5 12'x4' solar panels, HP50HA heat pump, 8mil solar cover, borates, TF-100 test kit, SONOS, Doheny's Discovery Robot, hot tub on bleach

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    Re: lowering TA

    Thanks to everyone.
    But I think I'll quit, went thru this 3 times & TA hasn't budged.
    Would it make any difference if I went to pH 7.0 instead of 7.2?
    19,800 gallons (closed/winter 18,654 gal); plaster; 18x34 Ft kidney bean shape, Depth 3Ft-5Ft. Built 1992
    Pentair Whisper Flow Pump 1HP. Winter safety cover w anchors.
    Sand filter, Pentair Sand Dollar Top Mount Model SD80; Effective Filtration Area 3.5SF
    - FlowRate 75GPM, 8Hr 36,000, 10Hr 45,000, 12Hr 54,000; Pressure Weight 50PSI
    BBB (Hayward Chlorinator when leave town). Polaris 360 cleaner.

  5. Back To Top    #5
    Mod Squad pooldv's Avatar
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    Re: lowering TA

    You can try going to 7.0. Are you aerating back up to 7.8 or 8? That can help. The TA drops only measure 10ppm per drop. So, 3 times might not be enough to move it to the next 10.
    TFP Moderator
    If TFP helped you or saved you money - Become a TFP Supporter! <--Click here
    2012 build and pics, 20k gal gunite, black onyx pebblesheen, OK flagstone, IntellifoVS, cart filter w/Pleatco, IC40 SWG, Solartouch, 5 12'x4' solar panels, HP50HA heat pump, 8mil solar cover, borates, TF-100 test kit, SONOS, Doheny's Discovery Robot, hot tub on bleach

  6. Back To Top    #6

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    Re: lowering TA

    From what I recall reading, aeration wiil increase pH faster when the pH is lower, so you can go from 7 to 7.2 faster than 7.2 to 7.4. 1.3 ppm pH swing seems pretty high, are you getting bubbles coming out of your return jets or have a large fountain? I'd definitely consider borates to buffer the pH rise.

  7. Back To Top    #7

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    Re: lowering TA

    August 2016 update: I had to revisit this thread because I need to do this again, just the conditions of my pool I suppose. Hoping to help others who might have this issue of "pool is requiring too much acid".
    I failed to post last year that after I wrote " I quit after 3 attempts", that I re-tested TA 6 days after the final attempt & my TA was TA 60 so good news to me; and that the acid demand was more reasonable which was the whole reason for doing it. My acid demand seems to be most reasonable around a TA of 50-55 but TA 60 was just fine so I left it at that
    Also based on my experience, and what someone posted above:
    - I am going to target pH 7.0 instead of pH 7.2 (pool calculator indicates if you want to lower TA you can target pH 7.0-7.2).
    -I'm going to aerate until my pH is in the pH 7.8 range (pretty sure last year that I only went to pH 7.5); then I'm going to lower pH to pH 7.5; then I'm going to wait 6 days before retesting TA, and then hit it again with acid if I'm not happy because the TA is not in the 50-60 range.

    FWIW, I did have borates in the pool during the years PRIOR to this "too much acid required" problem. I liked the borates, just to lazy to do it again so maybe this will inspire me to do it next season?
    19,800 gallons (closed/winter 18,654 gal); plaster; 18x34 Ft kidney bean shape, Depth 3Ft-5Ft. Built 1992
    Pentair Whisper Flow Pump 1HP. Winter safety cover w anchors.
    Sand filter, Pentair Sand Dollar Top Mount Model SD80; Effective Filtration Area 3.5SF
    - FlowRate 75GPM, 8Hr 36,000, 10Hr 45,000, 12Hr 54,000; Pressure Weight 50PSI
    BBB (Hayward Chlorinator when leave town). Polaris 360 cleaner.

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