Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 6 of 6

Thread: Reducing TA in <1yr plaster pool

  1. Back To Top    #1

    Join Date
    May 2014
    Location
    California
    Posts
    9

    Reducing TA in <1yr plaster pool

    Hi

    Is my approach to lowering TA working as one should expect? Should I be doing this while my pool is only 10mo old?

    I'm trying to get my TA down from 110 (it went as high as 150 during the first few months of the pool). I'm dropping the pH down to below 7.2 and aerating with a small bubble aeration disk pushing about .5CFM of air. It seems as though the TA is dropping very slowly and it is hard to keep the pH down. It is a little hard to tell how far below 7.2 pH I get because the scale on my test is 6.8 and 7.2. I'm worried about dropping it below 7, so I haven't seen the test fully down at the 6.8 color. I'm using full strength MA adding between 48 and 64 oz at a time.

    Here is the acid additions and aeration time:
    date pH TA MA added Aeration time
    5/20 7.5 130 64oz 0
    5/21 7.3 128 7
    5/22 7.2 110 48 14
    5/23 7.3 100 48 12
    5/24 7.4 95 68 5+

    The TA of 95 was measured 4 hours after acid was added.
    The pH's listed are before acid addition


    As I under stand it, I should be aerating with the cover off. Normally I keep the cover closed when not in use. It's not too windy where I am, but it is California so I'm trying to be very drought conscious.

    Current Chemistry:
    pH 7.0 - 7.2, before this I have been keeping it below 7.6
    TA 90-100 was 130ppm at the start of aeration
    FC 1.5-2ppm
    CC 0 FAS/DPD
    CYA 25-30ppm
    CH 410 Pool was filled with well 220ppm well water, now maintained w softened water
    Salt 3400ppm
    Temp 73F

    Thanks,

    Chris
    32,400 gal in ground pool, Pebbletec Pearl Black finish, Black Coverstar Eclipse Cover
    Intelliflo Pump, Intellichlor SWG, Quad DE filter, Boostrite booster pump w/KreepyKrauly Legend cleaner
    SR Smith 10' diving board on U frames

  2. Back To Top    #2
    JasonLion's Avatar
    Join Date
    May 2007
    Location
    Silver Spring, MD
    Posts
    37,879

    Re: Reducing TA in <1yr plaster pool

    You are doing just fine. There is nothing to worry about with 10 month old plaster.

    It takes time to get TA down, longer because you are keeping the pool mostly covered. But you ill get there eventually.
    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

  3. Back To Top    #3

    Join Date
    May 2014
    Location
    California
    Posts
    9

    Re: Reducing TA in <1yr plaster pool

    Thanks Jason,

    Any harm in lowering the pH to 6.8 just so see what it looks like on the tester?

    Here are some pictures of two aerators I created:

    https://plus.google.com/photos/10232...CNa8mvbl8OLbJQ

    The venturi runs off the pool cleaner line. The aeration disk runs off a surplus air pump I had. To put air down at 8' you would need a pump capable of about .5-1 CFM at 3psi.

    The venturi outputs about .5CFM while the air pump is putting out about 1 CFM. Both are very fine bubbles. The venturi is cheap to build, but is driven by a 1.5 HP pump. The airpump would cost around $50-$100 or more but only uses 100W

    Thanks,
    Chris
    32,400 gal in ground pool, Pebbletec Pearl Black finish, Black Coverstar Eclipse Cover
    Intelliflo Pump, Intellichlor SWG, Quad DE filter, Boostrite booster pump w/KreepyKrauly Legend cleaner
    SR Smith 10' diving board on U frames

  4. Back To Top    #4
    JasonLion's Avatar
    Join Date
    May 2007
    Location
    Silver Spring, MD
    Posts
    37,879

    Re: Reducing TA in <1yr plaster pool

    If the PH will only be low for a short while, lowering to around 6.8 shouldn't be a problem. You don't want to leave it that low for long however.
    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

  5. Back To Top    #5

    Join Date
    May 2014
    Location
    California
    Posts
    9

    Re: Reducing TA in <1yr plaster pool

    Thanks!

    Is it safe to swim at a level of 6.8 pH? Doesn't seem too acidic, but the pool service guy used to say don't swim for 3 hours after he added acid.

    Chris
    32,400 gal in ground pool, Pebbletec Pearl Black finish, Black Coverstar Eclipse Cover
    Intelliflo Pump, Intellichlor SWG, Quad DE filter, Boostrite booster pump w/KreepyKrauly Legend cleaner
    SR Smith 10' diving board on U frames

  6. Back To Top    #6
    JasonLion's Avatar
    Join Date
    May 2007
    Location
    Silver Spring, MD
    Posts
    37,879

    Re: Reducing TA in <1yr plaster pool

    Low PH won't kill you, but it tends to be rather unpleasant, burning eyes and itchy skin. Most people are not happy swimming unless the PH is 7.2 or higher, though there is some variation from person to person.

    The wait after adding acid is because the acid won't have mixed throughly and so the local PH might be far lower than what the PH will be after the acid is mixed in.
    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

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •