Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 5 of 5

Thread: Lowering TA, Just making sure I'm doing it correctly.

  1. Back To Top    #1

    Lowering TA, Just making sure I'm doing it correctly.

    Well my PH and TA have been getting high, so I've decided to do something about it finally. Ive never had to lower TA so i just want to check that i'm doing ti correctly. Today's test results were:

    FC 5
    CH 250
    TA 250
    PH 8.2
    CYA 20

    So according to what I've read, I've got about 4 gallons of MA, and the LPS told me to only dose about 2 qts at a time. I've made 2 DIY pvc aerators. I just put in the first dose of MA and i'm gonna wait about a half hour to check the ph again.

    It's my understanding that i should only add more MA once the ph reaches about 7.6 again correct? Anything else i should know or am missing?
    23000, Sand, IG, Plaster, Century Pool/Jetted Tub Motor 1.5HP, Rainbow Lifegard Feeder Model 300

  2. Back To Top    #2
    linen's Avatar
    Join Date
    Jul 2010
    Location
    Twin Cities, MN
    Posts
    8,649

    Re: Lowering TA, Just making sure I'm doing it correctly.

    I am assuming you have read: http://www.troublefreepool.com/pool-...l%20alkalinity?

    Basically use poolcalculator.com to calculate how much MA will bring your pool down to 7.2 pH. Then slowly pour the MA in front of the return. Aerate to raise pH up to 7.8, then repeat and lower to 7.2, repeat, repeat, repeat, until you reach your target TA level.

    By the way, your ph is probably higher than 8.2 (limits of most tests), so your first dose may not lower as far as you are expecting.
    TFP Expert who uses Pool School and my TF100 test kit along with PoolMath for my: Round 11K gallon AGP with deep end, 20" sand filter, Matrix 1hp 2spd, 6 2ftX20ft solar panels (and solar cover!), Intex SWCG (copper bars disconnected) and a Rubadub hot tub (chlorine). The SLAM process is not finished until: 1. CC < 0.5 ppm, 2. An OCLT < 1.0 ppm and, 3. The water is crystal clear.

  3. Back To Top    #3
    Richard320's Avatar
    Join Date
    Jan 2010
    Location
    San Dimas, CA (LA County)
    Posts
    18,768

    Re: Lowering TA, Just making sure I'm doing it correctly.

    2 qts is barely going to touch things. And you may also be above 8.2 - that's as high as the tester reads. You could be at 8.5 or beyond!

    Plug the numbers into Pool Calculator. All the numbers. It will give you the dosage to achieve the results you want. MA dosage will vary depending upon the TA level, so be sure to enter all the numbers. I recommend prediluting the acid in a bucket of water then pour it slowly in front of a return so it mixes fast. A few passes with the brush will also stir things up nicely.

    When I went after TA, I dropped pH to 7.0, aerated it for a couple hours, then retested pH and plugged the numbers in to get back to 7.0. No point waiting to get up to 7.6 (You might not have to wait long anyway) as it works faster at low pH.
    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.
    A pool is like a pet - you have to feed it every day, even the days you don't want to play with it!

  4. Back To Top    #4

    Re: Lowering TA, Just making sure I'm doing it correctly.

    ok great thanks for the help...

    Just tested again and ph is at about 7.2, I'll just keep re-calculating and watching it. Seems as though you should add more MA as soon as PH rises back correct? No reason to wait 8 hours in between doses?
    23000, Sand, IG, Plaster, Century Pool/Jetted Tub Motor 1.5HP, Rainbow Lifegard Feeder Model 300

  5. Back To Top    #5
    linen's Avatar
    Join Date
    Jul 2010
    Location
    Twin Cities, MN
    Posts
    8,649

    Re: Lowering TA, Just making sure I'm doing it correctly.

    You can lower it more often if you are willing/able.
    TFP Expert who uses Pool School and my TF100 test kit along with PoolMath for my: Round 11K gallon AGP with deep end, 20" sand filter, Matrix 1hp 2spd, 6 2ftX20ft solar panels (and solar cover!), Intex SWCG (copper bars disconnected) and a Rubadub hot tub (chlorine). The SLAM process is not finished until: 1. CC < 0.5 ppm, 2. An OCLT < 1.0 ppm and, 3. The water is crystal clear.

Posting Permissions

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