Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 12 of 12

Thread: How do I determine 'normal' for TA/pH balance

  1. Back To Top    #1

    Join Date
    Sep 2016
    Location
    Houston, TX
    Posts
    30

    How do I determine 'normal' for TA/pH balance

    Hello TFPer's

    I took over pool service, drained and refilled due to high CYA (thanks pool man!). I'm back on the steady maintenance and numbers (I think) and have a stenner maintaining chlorine levels and am using pinch a penny liquid bleach (10%). Pool plaster is prolly 7ish years in age. My question is how frequently I should expect pH to rise and how often to add acid. It seems with a TA of 90 that my pH of 7.6 goes up to 8 in about 2 days. No fill water or rain has occurred. No water features and no aeration.

    Here are my numbers (I've been testing almost daily to understand the numbers and keep a log):
    10/1 Reading (added 20oz of acid after reading)
    FC - 5
    pH - 8
    TA - 90

    10/2 Reading
    FC - 5
    pH - 7.6
    TA - 90

    10/5 Reading (added 20oz of acid after reading)
    FC - 5.5
    pH - 8
    TA - 90

    My fill water has a pH of 7 (or maybe lower as I cannot read below that) and a TA of 160, so after the refill in early Sept, I spent a while dumping a bunch of acid to lower TA, then aerating to bring pH back up. I got TA down to 80 and figured that was where it needed to be. So I am just trying to figure out what is 'normal'. If adding 14oz every 2 days in my normal, then ok, but I've read others hardly adding any acid at all on a routine basis. Just need some help in trying to determine what is my balancing point.

    And a followup question, if adding 14oz every couple of days is normal (and for those folks who accept this as normal), do people actually get a stenner to do acid automation? That seems like a risky proposition to me, but I thought I'd ask.

    Thanks for all of the awesome input!
    15K gal rectangle with 1K gal spill over round spa | K-2006 Test kit | IG plaster | B2983 1.5HP 2 speed pump| Triton TR100 sand filter | Pentair MiniMax 400k BTU heater | Stenner 45MPHP10 w/ 15g tank | Dolphin M400 robot | screened pool cage covers pool entirely to keep it debris free and adds SPF | sun exposure estimate 8hr daily.

  2. Back To Top    #2
    TFP Guide

    pabeader's Avatar
    Join Date
    May 2015
    Location
    Dallas Ga
    Posts
    3,232

    Re: How do I determine 'normal' for TA/pH balance

    From my reading around the different threads, I see that as low as 50 is still considered 'normal' It really depends on your pH rise. As you have noticed, higher TA caused pH to rise quicker. I would say, keep pushing TA down until the pH rise is negligible.

    Make sure you use Pool Math to watch the CSI range, so that you don't run into scaling issues.

    - - - Updated - - -

    Folks with things like bubblers, fountains and other active stuff that cause pH rise will sometimes do a stenner type arrangement for MA additions.
    Bob - Palm Beach by San Juan Pools. approx 5000 gals Pentair 320 cartridge filter (all new guts installed by me) Goldline SWG Intermec 104 TImer Test kit: TF-100 w/Speed Stir

  3. Back To Top    #3
    Mod Squad Patrick_B's Avatar
    Join Date
    Jun 2011
    Location
    WestTexas
    Posts
    12,702

    Re: How do I determine 'normal' for TA/pH balance

    Focus on your pH first, always. You've already figured out how to lower the TA, and you're doing well with that. People like us will always have to add acid, and its just the way it is when you have high TA/pH makeup water. No getting around it, but acid demand will lower when your TA gets lower. Lots of users see an easier situation with a TA around 60 or perhaps 50. There isn't a magic number, you'll just have to experiment and see what happens in your pool. People that have low acid demand just have better water in terms of Alkalinity content. Most however are more like us with high TA, especially in this part of the country.

    When you can maintain a mid 7 or slightly higher pH with far fewer acid additions, you'll know, but it will always be a fight. My makeup TA is pretty high at 130, but my pH is above 8, so I feel your pain.
    TFP Moderator
    Essential Links:
    TF-100 Test Kit, ABC's Of Pool Chemistry, Test Kits, SLAM Your Pool
    28K Gal IG FreeForm, CLI Quartz, Flagstone, 36"SF, Pentair VS Pump, EasyTouch W/Remote, Rheem 400KBTU Htr

  4. Back To Top    #4

    Join Date
    Jul 2015
    Location
    Tempe, AZ
    Posts
    192

    Re: How do I determine 'normal' for TA/pH balance

    My fill water has a TA over 200 - so there is always upward pressure on my TA and pH.

    My pH rise slows way down when I keep the TA in the 50-60 range. It won't really go over 7.8 or 7.9 unless the TA goes over 60. And it's a slow rise (4-5 days) from 7.5 to 7.8.

    If I were you, I'd keep dropping the TA by 10 and see what happens. Yo will probably find a happy place somewhere lower.
    John - 16,000 gallon | in ground | pebble | Triton II sand filter | TF100 | speedstir | Hayward Phoenix 2x

  5. Back To Top    #5

    Join Date
    Sep 2016
    Location
    Houston, TX
    Posts
    30

    Re: How do I determine 'normal' for TA/pH balance

    Great feedback, thanks all. I'll keep dropping TA by 10 to try to find the sweet spot. Today I've gotta add makeup water (high TA, low pH) due to evap, so it's gonna take a couple of weeks. Will report back.
    15K gal rectangle with 1K gal spill over round spa | K-2006 Test kit | IG plaster | B2983 1.5HP 2 speed pump| Triton TR100 sand filter | Pentair MiniMax 400k BTU heater | Stenner 45MPHP10 w/ 15g tank | Dolphin M400 robot | screened pool cage covers pool entirely to keep it debris free and adds SPF | sun exposure estimate 8hr daily.

  6. Back To Top    #6

    In the Industry

    duraleigh's Avatar
    Join Date
    Apr 2007
    Location
    Sebring, Florida
    Posts
    28,812

    Re: How do I determine 'normal' for TA/pH balance

    Going from 90 to 50 in 10 increments is problematic. The resolution of the test is 10 ppm so I suggest you simply bring it right on down with the acid/aeration method and not wait the month or more to drop it to 50 ppm.
    Dave S. - Forum owner
    42k vinyl and concrete pool, 1.5hp pump, 140gpm filter
    TFTestkits , PoolMath , Pool School

  7. Back To Top    #7

    Join Date
    Sep 2016
    Location
    Houston, TX
    Posts
    30

    Re: How do I determine 'normal' for TA/pH balance

    Oh, so drop to 50 as quickly as I can and then see how it behaves. Makes sense, thanks Dave.
    15K gal rectangle with 1K gal spill over round spa | K-2006 Test kit | IG plaster | B2983 1.5HP 2 speed pump| Triton TR100 sand filter | Pentair MiniMax 400k BTU heater | Stenner 45MPHP10 w/ 15g tank | Dolphin M400 robot | screened pool cage covers pool entirely to keep it debris free and adds SPF | sun exposure estimate 8hr daily.

  8. Back To Top    #8
    kellyfair's Avatar
    Join Date
    Jun 2016
    Location
    Tampa, FL
    Posts
    171

    Re: How do I determine 'normal' for TA/pH balance

    Quote Originally Posted by Patrick_B View Post
    Lots of users see an easier situation with a TA around 60 or perhaps 50.
    This is me. My TA is 60, and my pH literally has been at 7.5 all summer long - never changes!
    Kelly, Tampa FL
    15' by 4' Intex above ground metal frame, about 5300 gallons
    Intex 120V Krystal Clear Sand Filter Pump & Saltwater System CG-28679 with E.C.O.
    TF100 Kit and Speedstir
    Intex Auto Cleaner - works great!

  9. Back To Top    #9

    Join Date
    Sep 2016
    Location
    Houston, TX
    Posts
    30

    Re: How do I determine 'normal' for TA/pH balance

    OK circling back on this topic, my TA is nearing 50. So I am curious, what do I do if the pH rises above 7.8 with a TA of 50?
    15K gal rectangle with 1K gal spill over round spa | K-2006 Test kit | IG plaster | B2983 1.5HP 2 speed pump| Triton TR100 sand filter | Pentair MiniMax 400k BTU heater | Stenner 45MPHP10 w/ 15g tank | Dolphin M400 robot | screened pool cage covers pool entirely to keep it debris free and adds SPF | sun exposure estimate 8hr daily.

  10. Back To Top    #10
    TFP Guide

    pabeader's Avatar
    Join Date
    May 2015
    Location
    Dallas Ga
    Posts
    3,232

    Re: How do I determine 'normal' for TA/pH balance

    Limit the use of the spillover. With that running, it will eventually rise up there. You might want to let it though, at least for a day or two. It might actually settle in there and not go any higher. If it does, you can always knock it back down with a little MA.
    Bob - Palm Beach by San Juan Pools. approx 5000 gals Pentair 320 cartridge filter (all new guts installed by me) Goldline SWG Intermec 104 TImer Test kit: TF-100 w/Speed Stir

  11. Back To Top    #11

    Join Date
    Sep 2016
    Location
    Houston, TX
    Posts
    30

    Re: How do I determine 'normal' for TA/pH balance

    So my spillover does not create any bubbles, it's just more of an overflow from the spa to the pool: Mike has shared 1 photo with you! | Flickr

    I guess what you are saying is the amount of acid required to drop the pH from say 8 to 7.6 should have a minimal effect on TA, right? And I should just closely monitor TA before I do.
    15K gal rectangle with 1K gal spill over round spa | K-2006 Test kit | IG plaster | B2983 1.5HP 2 speed pump| Triton TR100 sand filter | Pentair MiniMax 400k BTU heater | Stenner 45MPHP10 w/ 15g tank | Dolphin M400 robot | screened pool cage covers pool entirely to keep it debris free and adds SPF | sun exposure estimate 8hr daily.

  12. Back To Top    #12

    Join Date
    Jan 2016
    Location
    grande prairie
    Posts
    28

    Re: How do I determine 'normal' for TA/pH balance

    I run 60-70 ta in my pool and don't use barely any acid but the tub eats quite a bit even with a 50-60 ta. I sure notice my pool and tub are quite a bit different than every other pool.
    113,000L indoor saltwater pool built in 1981. 1000lb sand filter, filed with quartz with 2hp single speed pump.
    4602L indoor saltwater whirlpool built in 1981. 500lb sand filter with 2hp single speed pump. Both controlled by chemtrol250 and Hayward pro swg's.

Posting Permissions

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