Become a TFP Supporter Welcome to our new server and new forum software. Pool School
Results 1 to 9 of 9

Thread: Why does my PH keep going up?

  1. #1
    Junior Member
    Join Date
    Jul 2007
    Posts
    7

    Why does my PH keep going up?

    I have a one yr old 10,000 gal in ground Gunite pool, water temp is 77 degrees. I test chlorine and PH daily, my PH goes up about .2ppm-.4ppm daily, my TA seems to go down quickly, but not as fast as the PH changes. My chlorine is always stable, I add about 10oz daily. Can someone tell me why my PH might be going up so much. I know having a new pool can cause this, but the pool is a year old and the PH doesn't seem to be slowing down at all.


    Any answers welcomed.

    Thanks
    Froggybabies
    24000 gal inground vinyl
    Sand filter

  2. #2
    Administrator JasonLion's Avatar
    Join Date
    May 2007
    Location
    Silver Spring, MD
    Posts
    34,594
    PH goes up for two reasons. If your plaster is less than one year old the plaster is still curing. As the plaster cures it raises the PH. Also, the combination of high TA and aeration will raise PH. If you post a full set of test results we might be able to suggest some adjustments that will slow or eliminate the PH increase.
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
    TFP Admin. Creator of PoolMath and Pool Calculator. Other handy links: Support this site, TF Test Kits, Pool School

  3. #3
    Junior Member
    Join Date
    Jul 2007
    Posts
    7
    My pool was finished about 13 months ago. My test numbers from the last few days are:

    FC 4
    PH 7.8
    TA 90
    CH 280
    CYA 40

    I added 24 oz. of MA to drop it to 7.2, because it goes up so rapidly. Maybe I am dropping it too much? Anyway,
    my numbers for the following day were:

    FC 3
    PH 7.6
    TA 80

    I added 19 oz. of MA. The following day the PH was up to 7.9 and the TA was down to 70. I added 24 oz. of MA and added 50 oz. of baking soda?

    Maybe this is normal. I just feel like my PH and TA, but especially my PH, is moving around alot.

    Thanks.
    Froggybabies
    24000 gal inground vinyl
    Sand filter

  4. #4
    Mod Squad Butterfly's Avatar
    Join Date
    May 2007
    Location
    South Carolina
    Posts
    10,505
    Hi rw,

    Here is a portion of a post I found that may have more items for you to consider............(I copied/pasted this partial post months ago, and apologize that I am unable to credit the author. However, it is one of the TFP gurus.)

    "PH can go up for a number of reasons. The most common is CO2 outgassing caused by aeration of the pool (rain, kids playing, SWG, waterfall, spa, etc). Blown in dust can sometimes be fairly basic, raising the PH. New plaster will raise the PH for several months to a year.

    If you compensate for PH increases from CO2 outgassing by adding acid reguarly, the TA will go down over time."


    If you add all your pool and equipment info in your signature, it would be helpful.

    What test kit are you using?

    Do you have water features, bubblers, etc?
    TFP Moderator TF100 Test Kit TF100 TestKit YouTube Channel PoolMath
    You're done SLAMing when:
    1)You lose 1ppm or less FC overnight, & 2)You have .5ppm CC's or less, & 3)your water is clear.

    ~ Do not use a sledge hammer to swat a mosquito. ~

    If you found TFP helpful and we saved you money ... Become a TFP Supporter!

  5. #5
    Administrator JasonLion's Avatar
    Join Date
    May 2007
    Location
    Silver Spring, MD
    Posts
    34,594
    You should allow TA to fall to around 60 (or even 50 if you don't have an SWG).

    If you have a SWG, I suggest that you raise CYA to between 60 and 80.

    That should greatly reduce the rate of PH increase, particularly when the PH is around 7.6 to 7.8.
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
    TFP Admin. Creator of PoolMath and Pool Calculator. Other handy links: Support this site, TF Test Kits, Pool School

  6. #6
    Junior Member
    Join Date
    Jul 2007
    Posts
    7
    To answer jj, I use a Taylor K2005 kit. We have a 10K gallon IG, gunite pool. Cartridge filter and one water decent. I have kept it off for the past two weeks to see if that was causing my PH to rise. It hasn't seemed to make a difference.

    In response to JasonLion, I don't have an SWG so you are saying that it is ok to let my TA drop to 60? I have never let it drop that low before.

    Thank you both for your input.

    rw
    Froggybabies
    24000 gal inground vinyl
    Sand filter

  7. #7
    Administrator JasonLion's Avatar
    Join Date
    May 2007
    Location
    Silver Spring, MD
    Posts
    34,594
    Yes, as long as you are using bleach for chlorine and have CYA around 40 you should be fine with TA down around 60, perhaps even just a little lower. It is crucial to have a higher TA level when using trichlor tablets, which most people use, so that is why much higher numbers get quoted most places.

    The rate of PH increase is higher when TA is higher and when PH is lower. Lowering TA and letting pH go up just a little will slow, or perhaps stop, the rate of PH increase significantly.
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
    TFP Admin. Creator of PoolMath and Pool Calculator. Other handy links: Support this site, TF Test Kits, Pool School

  8. #8
    Senior Member
    Join Date
    May 2007
    Posts
    184
    Quote Originally Posted by JasonLion
    Yes, as long as you are using bleach for chlorine and have CYA around 40 you should be fine with TA down around 60, perhaps even just a little lower. It is crucial to have a higher TA level when using trichlor tablets, which most people use, so that is why much higher numbers get quoted most places.

    The rate of PH increase is higher when TA is higher and when PH is lower. Lowering TA and letting pH go up just a little will slow, or perhaps stop, the rate of PH increase significantly.
    This is interesting. I use liquid chlorine purchased from my pool store (it's cheaper than bleach in my area) and pour it in my Liquidator. I too have pH rise but not as bad as the OP. I usually keep my TA around 100. I'm going to try it at 60 and see what happens. I have a vinyl pool liner so it should be fine.
    15,500 gal, inground gunite pool with 7 ft spa, 2 speed pump 2hp/.33hp, 3/4 hp booster pump, Intermatic P1353 timer, AutoPilot SC-48, Sand filter with ZeoBest, Heater, that I never use . . .

  9. #9
    Junior Member
    Join Date
    Jul 2007
    Posts
    7
    Thanks Jason, I will try your suggestion and see how it works.

    rw
    Froggybabies
    24000 gal inground vinyl
    Sand filter

Posting Permissions

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