Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 7 of 7

Thread: PH question

  1. Back To Top    #1

    Join Date
    Apr 2016
    Location
    Dayton, Ohio
    Posts
    31

    PH question

    Tested today at pH 7.3, FC is 10. I had added some muriatic acid to get pH to 7.5, but being a little ignorant maybe, I added 5 pounds CYA 2 days ago as well since I'm trying to get CYA up to 70 from 40. Is CYA a weak acid? No one will use pool until weekend at least because too cold still here. 2/3 CYA is dissolved. TA tested at 110 before these additions and ideally is 70-80.

    Should i I not bother with anything now and see what happens in a few days. The pH presumably will slightly go down more with all CYA dissolved. Do I bother increasing pH with borax or hope for good weather and have kids hopefully aerate enough to get TA down some?

    What at are the hard levels for pH where I should add something to change it immediately? Seems like more worrying than necessary on my part.
    26,000g IG, Fiberglass side/Concrete bottom, epoxy paint, Pentair IC40 SWG, Pentair Cartridge Filter 420, Pentair Intelliflow 3 HP VS pump, Pentair 120 Heat Pump, pool installed 11/2015, painted and equipment installed 4/2016. City Water.

  2. Back To Top    #2

    TFP Guide

    AimeeH's Avatar
    Join Date
    Apr 2012
    Location
    Columbia SC
    Posts
    1,837

    Re: PH question

    Ph of 7.5-7.8 is ideal. I personally wouldn't stress about 7.3 but how are you testing?

    Aerating will indeed bring up your PH but will not affect your TA.
    18*36*23 true "L" vinyl IG 29,000 gallons. SWG. TF-100 test kit.
    http://tftestkits.net/splash-page.html

  3. Back To Top    #3
    Mod Squad YippeeSkippy's Avatar
    Join Date
    Jan 2012
    Location
    'burbs of Augusta, Georgia
    Posts
    6,481

    Re: PH question

    How are you testing? Which test kit? What has your pH been running up to now? When did you last check?

    pH tests aren't accurate with FC over 10. Does that include @10, I'm not always sure? You could be well below 7.3 since higher chlorine usually makes the pH test read *higher* than actual. I think if you're confident in your levels I'd leave it alone. If you are not you might want to use a bit of Borax and retest.
    My Amazon Smile for November12K Fiberglass IG, Infinity 4000 automatic cover, SWCG, Hayward Sand Filter, Hayward 1.5 Pump, Doheny Discovery Robot, Savi Melody LED pool lights, outdoor speakers and other assorted doo-dads. Sundance Altamar Hot Tub.
    Our pool build--> Our Pool Solved Our Sloping Yard Skippy's Cheap Pool Cooler -->Skippy's New Fountain

  4. Back To Top    #4

    Join Date
    Apr 2016
    Location
    Dayton, Ohio
    Posts
    31

    Re: PH question

    I've used the pH test in my TF100 and the kit PB gave me. Been testing every couple days. pH in7.8 range before I added acid a week ago to 7.6, although FC 12-13 then , going down now with CYA going in and FC going down, makes it hard to keep straight.

    Why wouln't aerating bring down TA, do I have to lower pH even more first?
    26,000g IG, Fiberglass side/Concrete bottom, epoxy paint, Pentair IC40 SWG, Pentair Cartridge Filter 420, Pentair Intelliflow 3 HP VS pump, Pentair 120 Heat Pump, pool installed 11/2015, painted and equipment installed 4/2016. City Water.

  5. Back To Top    #5

    TFP Guide

    AimeeH's Avatar
    Join Date
    Apr 2012
    Location
    Columbia SC
    Posts
    1,837

    Re: PH question

    Muratic acid will lower both TA and PH. Aerating will then bring your PH back up and not affect TA.

    If you find yourself needing to lower TA, that is a process where you use MA (muratic acid) which lowers both and then aerate to bring PH back up.
    18*36*23 true "L" vinyl IG 29,000 gallons. SWG. TF-100 test kit.
    http://tftestkits.net/splash-page.html

  6. Back To Top    #6

    Join Date
    Apr 2016
    Location
    Dayton, Ohio
    Posts
    31

    Re: PH question

    Quote Originally Posted by AimeeH View Post
    Muratic acid will lower both TA and PH. Aerating will then bring your PH back up and not affect TA.

    If you find yourself needing to lower TA, that is a process where you use MA (muratic acid) which lowers both and then aerate to bring PH back up.
    Ok, I have been confused it seems. So the muriatic acid addition actually brings down TA, and the aeration increases pH to normal? For some reason I assumed the aeration decreased the TA and increased pH both. Please confirm. Is there an easy explanation for the acid decreasing TA itself?
    26,000g IG, Fiberglass side/Concrete bottom, epoxy paint, Pentair IC40 SWG, Pentair Cartridge Filter 420, Pentair Intelliflow 3 HP VS pump, Pentair 120 Heat Pump, pool installed 11/2015, painted and equipment installed 4/2016. City Water.

  7. Back To Top    #7
    Richard320's Avatar
    Join Date
    Jan 2010
    Location
    San Dimas, CA (LA County)
    Posts
    18,768

    Re: PH question

    Quote Originally Posted by JohnInDayton View Post
    Ok, I have been confused it seems. So the muriatic acid addition actually brings down TA, and the aeration increases pH to normal? For some reason I assumed the aeration decreased the TA and increased pH both. Please confirm. Is there an easy explanation for the acid decreasing TA itself?
    Easy? Maybe. I'll try.

    When you want to raise TA, you add Baking Soda. So TA = Baking Soda. What happens when you mix baking soda and acid? It fizzes and foams and releases carbon dioxide gas. It's no longer baking soda. The alkaline part has just bubbled away. Same thing when you add acid to the pool. It reacts and the gas escapes.

    You know what else releases carbon dioxide gas? Shaking a bottle of soda. Aerating your pool is exactly the same as shaking a soda. The reason you can drink a soda faster after it's been poured over ice and/or has gone flat is because.... here it comes... the pH went up so it's no longer so acidic.

    If you wait long enough, the C02 will escape the surface of the pool, which is why pH climbs over time. Aerating it just accelerates the process, hence the pH rises. The alkalinity was gone as soon as the acid mixed.

    A final attempt: Lowering TA goes along with lowering pH. It's like a ratchet and a bolt. You push down (acid) and then you lift the ratchet (aerate). The ratchet is the pH, it comes back up. The TA is the bolt. It stays down.
    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!

Posting Permissions

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