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

Thread: pH won't stay down

  1. Back To Top    #1
    tlwilson's Avatar
    Join Date
    Aug 2010
    Location
    Nebraska
    Posts
    50

    pH won't stay down

    I am getting frustrated with the pH in my pool. Last weekend I brought it down to 7.2, aerated and got the TA to 80 from 120. Now 5 days later, it is back up to 7.6 and TA is 110. Every time I add liquid chloring 12.5%, the pH rises about .2. I did add about 4 inches of fresh water. I tested my tap water and the TA was 180. Should I just resign myself to pH rising and add MA routinely at 7.6 to stay on top of it?
    24,000 Gal In Ground pool
    Vinyl Liner; Sand Filter
    Pentair Intelliflo pump
    Pentair IntelliChlor IC40 SWG
    Raypak Gas Heater

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

    Re: pH won't stay down

    Any time the PH gets to 7.8, lower it down to 7.2. If that is happening too frequently, so that it gets annoying, you might want to think about adding an automatic acid feed system.

    Bleach raises the PH right when you add it, and then the PH comes down again as the chlorine gets used up. There is only a very tiny net change in the PH due to bleach/liquid chlorine, too small to measure in most cases.
    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

    Re: pH won't stay down

    I have the same issue and keep lowering it almost weekly. My TA is about 90-110, FC 2-5, CYA 30-40

    I find it a bit difficult to see the exact PH reading (Taylor K1000), but when it's around 7.8 (against white background) I lower it with 12oz of ph down. Then I test again in a couple hours and lower it again if needed.

    One pool store owner told me it's a common issue with in-ground pools in this area (NE) and that's normal. I don't know if that's accurate info, but he is not seasonal kid, he's been at the same location for more than 10 years
    Bill
    18'X4' 7600 Gal AG
    3/4 HP Pentair Pump
    Hayward S166T 100 lb sand filter

  4. Back To Top    #4
    tlwilson's Avatar
    Join Date
    Aug 2010
    Location
    Nebraska
    Posts
    50

    Re: pH won't stay down

    Quote Originally Posted by JasonLion
    Bleach raises the PH right when you add it, and then the PH comes down again as the chlorine gets used up. There is only a very tiny net change in the PH due to bleach/liquid chlorine, too small to measure in most cases.
    Low and behold, pH went down on its own to 7.2 after a hot sunny day and chlorine got used up. Previously I had tested the pH this morning. I add bleach at night and don't lose any chlorine overnight, so I was testing the pH at the time it would be highest. Thanks! Another key thing to learn.
    24,000 Gal In Ground pool
    Vinyl Liner; Sand Filter
    Pentair Intelliflo pump
    Pentair IntelliChlor IC40 SWG
    Raypak Gas Heater

  5. Back To Top    #5

    In the Industry

    duraleigh's Avatar
    Join Date
    Apr 2007
    Location
    Sebring, Florida
    Posts
    30,084

    Re: pH won't stay down

    Bleach will have no overall effect on pH. There is a temporary upswing just as bleach is introduced but pH quickly returns to it's original level.

    I'm not sure why your pH went up and then down, but don't look for bleach be the answer. I have changed the FC in my pool by 10ppm and can never detect any appreciable change in pH sfter just a few hours.
    Dave S.
    42k vinyl and concrete pool, 1.5hp pump, 140gpm filter
    TFTestkits , PoolMath , 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
  •