Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 17 of 17

Thread: Should I lower my pH?

  1. Back To Top    #1

    Join Date
    Jun 2013
    Location
    Orange County, NY
    Posts
    51

    Should I lower my pH?

    Tested last night and here is what I had...

    FC - 6.5
    CC - 0.5
    pH - 7.8
    TA - 120
    CH - 120
    CYA - 110

    I am losing 1 - 1.5 ppm FC overnight. I want to keep FC at 7 - 7.5 while I work on getting my CYA down, but can only do small water replacements with well water so it will take a long time. Looks to me like I should lower my pH, no? I'm going to aim for pH of 7.5.

    What do you think?
    - Max
    __________________________________
    20k gal, inground vinyl, 1 1/2 HP Hayward SuperPump, HW Veriflow XL Sand Filter, Hayward Aqua Rite T-Cell-9, AquaComfort Heat Pump ACT-1100
    Hayward TigerShark robotic cleaner

  2. Back To Top    #2

    In the Industry

    duraleigh's Avatar
    Join Date
    Apr 2007
    Location
    Sebring, Florida
    Posts
    30,085

    Re: Should I lower my pH?

    MT,

    Keep your questions under one thread. Responders get very confused when you start too many threads.
    Dave S.
    42k vinyl and concrete pool, 1.5hp pump, 140gpm filter
    TFTestkits , PoolMath , Pool School

  3. Back To Top    #3

    Join Date
    Jun 2013
    Location
    Orange County, NY
    Posts
    51

    Re: Should I lower my pH?

    You mean my recent questions about muriatic acid and borax shelf life? Or my last post with test results? Should have all been on same thread?
    - Max
    __________________________________
    20k gal, inground vinyl, 1 1/2 HP Hayward SuperPump, HW Veriflow XL Sand Filter, Hayward Aqua Rite T-Cell-9, AquaComfort Heat Pump ACT-1100
    Hayward TigerShark robotic cleaner

  4. Back To Top    #4
    msgtdan's Avatar
    Join Date
    Jul 2011
    Location
    SW MO
    Posts
    653

    Re: Should I lower my pH?

    I usually lower at 7.8, because I have high TA fill water I know it's going to go back up so I go down to 7.2.
    Dan D
    Used 2003 Aqua Leader 27'x52", 17,800 w/10" hopper, SwimPro SW256T 250# sand filter, Hayward PowerFlo LX pump 1hp impellor, Emerson 1 1/2 hp motor, setup Aug 2012 Summer 2011 used Summer Escapes Ring pool 14' x 42", Intex 1600gph sand filter, HTH 6 way test kitTF-100 w/stirrer, Well water @ FC=0, PH=7.2, TA=290, CH=320

  5. Back To Top    #5

    Join Date
    Jun 2013
    Location
    Orange County, NY
    Posts
    51

    Re: Should I lower my pH?

    Ok, I have a PROBLEM now and need some help. The pool has a slight green tinge to it. It is still clear, but NOT blue.
    I think I was dumb to keep the FC around the MINIMUM (FC - 7 ppm) instead of what is the recommended target (FC - 12 ppm). As soon as I noticed the slight green look, I put in a bottle of bleach. After about 15 minutes of circulation, these are my test numbers:

    Currently:
    FC - 11
    CC - 0
    pH - 7.6

    as of yesterday:
    TA - 120
    CH - 110
    CYA - 110

    What should I do? The two things I changed in the past few days are:
    1. Stopped running my pump 24 hrs. Started running 12 hrs per day 10am - 10pm.
    2. Let the FC level drop below 7 ppm. I know one night it was at 6 ppm.

    I have people coming over tomorrow to swim. I want to fix the issue, but I'd like the pool to be swimable. Thanks in advance all!
    - Max
    __________________________________
    20k gal, inground vinyl, 1 1/2 HP Hayward SuperPump, HW Veriflow XL Sand Filter, Hayward Aqua Rite T-Cell-9, AquaComfort Heat Pump ACT-1100
    Hayward TigerShark robotic cleaner

  6. Back To Top    #6
    JasonLion's Avatar
    Join Date
    May 2007
    Location
    Silver Spring, MD
    Posts
    37,879

    Re: Should I lower my pH?

    I would run the FC level up to shock level right away. With high CYA levels it is very very difficult to recover once things start sliding out of control. Your best chance is to hit it hard as quickly as possible before things get out of control.

    Maintaining a pool with CYA at 100 or higher is very problematic. I strongly recommend replacing water to get the CYA level down to something more reasonable. Also, keep in mind that none of the CYA tests are capable of very much precision when measuring levels over 100, so your CYA level could easily be quite a bit higher than you think it is (or lower).
    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

  7. Back To Top    #7

    Join Date
    Jun 2013
    Location
    Orange County, NY
    Posts
    51

    Re: Should I lower my pH?

    I know its not the smartest thing to do, but I don't want to shock it until tonight because I;m having people over to swim today. It is a very very slight tinge of green. It is hardly noticeable, but I notice it. Last night I brought FC up to 17 ppm, CC was at 0.5.

    This morning, green tinge is no better, no worse. FC is 15 ppm and CC at 0.

    I figure since my CYA is so high, I'm due for a large water replacement anyway. So if it get's worse over the next 12 hrs before I can shock it, oh well.
    - Max
    __________________________________
    20k gal, inground vinyl, 1 1/2 HP Hayward SuperPump, HW Veriflow XL Sand Filter, Hayward Aqua Rite T-Cell-9, AquaComfort Heat Pump ACT-1100
    Hayward TigerShark robotic cleaner

  8. Back To Top    #8

    In the Industry

    duraleigh's Avatar
    Join Date
    Apr 2007
    Location
    Sebring, Florida
    Posts
    30,085

    Re: Should I lower my pH?

    You mean my recent questions about muriatic acid and borax shelf life? Or my last post with test results? Should have all been on same thread?
    Yes. When you are a responder, it is difficult to keep track. If you start too many threads, responders will simply skip your threads rather than try to sort them all out.
    Dave S.
    42k vinyl and concrete pool, 1.5hp pump, 140gpm filter
    TFTestkits , PoolMath , Pool School

  9. Back To Top    #9

    Join Date
    Jun 2013
    Location
    Orange County, NY
    Posts
    51

    Re: Should I lower my pH?

    Evening of July 3rd, I put enough bleach in to get the FC up to 17 ppm. Early yesterday morning, July 4th, FC level was at 15ppm. Pool water looking better, went from slightly noticeable green tint to almost no green tint. I brought the FC back up to 17 ppm.

    Had a July 4th party, bunch of people swimming in the pool all day. That night, FC tested at 10 ppm. So I decided to shock it (or close to shock levels). I added enough bleach to bring the FC up to 28 - 30 based on pool calc. But silly me, forgot to lower the pH first.

    This morning:
    FC = 28.5
    CC = 0
    pH = 8.2+ ?

    After getting the above results, pool looks good but not crystal clear like it was a week ago. I dumped a good amount of muriatic acid in before I left for work to lower the pH but did not have time to stick around and test its effect.

    My plan this evening is as follows, any comments welcome:

    1. Test the pH, FC, and CC.
    2. If pH is still too high, put in more muriatic acid (how low depends a bit on FC level).
    3. If pH is way low, too low for bleach addition to help, I'll add borax.
    4. As long as my CC is still 0, I plan on aiming for my FC to be 12 ppm. If FC tests higher than 14 ppm I will not add any bleach tonight.
    5. Test FC again before bedtime and tomorrow morning calculate my FC loss.

    Am I headed in the right direction?
    - Max
    __________________________________
    20k gal, inground vinyl, 1 1/2 HP Hayward SuperPump, HW Veriflow XL Sand Filter, Hayward Aqua Rite T-Cell-9, AquaComfort Heat Pump ACT-1100
    Hayward TigerShark robotic cleaner

  10. Back To Top    #10
    JasonLion's Avatar
    Join Date
    May 2007
    Location
    Silver Spring, MD
    Posts
    37,879

    Re: Should I lower my pH?

    The PH test results are invalid when FC levels are that high. You should ignore PH readings unless FC is 10 or lower.

    Since you have been adjusting the PH when the test results are invalid, chances are your have lowered the PH well below where it should be. You should make a point of checking and adjusting the PH as soon as the FC level gets down to something more reasonable, and in the meantime stop adjusting the PH. (This is but one of the many many hazards of trying to get by with high CYA levels.)
    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

  11. Back To Top    #11

    Join Date
    Jun 2013
    Location
    Orange County, NY
    Posts
    51

    Re: Should I lower my pH?

    Oh man I forgot about that! So now what should I do? Let the FC naturally drop down to 10 ppm or a little lower so I can get an accurate pH reading. Then adjust pH. Then bump the FC back up to 12 ppm?

    Does this mean don't swim in the pool until I have accurate pH test results?
    - Max
    __________________________________
    20k gal, inground vinyl, 1 1/2 HP Hayward SuperPump, HW Veriflow XL Sand Filter, Hayward Aqua Rite T-Cell-9, AquaComfort Heat Pump ACT-1100
    Hayward TigerShark robotic cleaner

  12. Back To Top    #12
    JasonLion's Avatar
    Join Date
    May 2007
    Location
    Silver Spring, MD
    Posts
    37,879

    Re: Should I lower my pH?

    The whole situation is problematic. The FC level won't come down any time soon, so you are kind of stuck.

    As I said before, you should replace water to get the CYA level down to something more reasonable, which would eliminate this problem.
    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

  13. Back To Top    #13

    Join Date
    Jun 2013
    Location
    Orange County, NY
    Posts
    51

    Re: Should I lower my pH?

    ok, so help me out with water replacement. not sure I'm committed to this yet, but it seems inevitable. My pool is ~ 23,000 gallons. A truckload of water carries 6,000 gallons. So I'd need two truckloads to do a 50% change.

    How do I drain my pool enough to know I can take the full 12,000 gallons, without draining it too much that I'll have a hard time making up the difference with well water?

    My pool has a main drain in the deep end and I can pump thru filter to waste.
    - Max
    __________________________________
    20k gal, inground vinyl, 1 1/2 HP Hayward SuperPump, HW Veriflow XL Sand Filter, Hayward Aqua Rite T-Cell-9, AquaComfort Heat Pump ACT-1100
    Hayward TigerShark robotic cleaner

  14. Back To Top    #14

    Join Date
    Jun 2013
    Location
    Orange County, NY
    Posts
    51

    Re: Should I lower my pH?

    Test results this evening:

    FC - 21
    CC - 0
    pH - 7.2
    TA - 120
    CYA - 100

    With the combo of high CYA, 8 ppm FC loss, the added muriotic acid, could I possibly be getting an accurate pH reading? The pool looks very clear and blue now. I'll check overnight FC loss to make sure I'm good. But at least I'll feel safe swimming tomorrow. Probably going to let FC make its way down to 10 - 12 and see how much daily bleach it takes to keep it there. I'll raise the pH up to 7.5 after the FC works its way down.

    But of course water replacement at least 50% is in my future, so I'm still looking for advice there.
    - Max
    __________________________________
    20k gal, inground vinyl, 1 1/2 HP Hayward SuperPump, HW Veriflow XL Sand Filter, Hayward Aqua Rite T-Cell-9, AquaComfort Heat Pump ACT-1100
    Hayward TigerShark robotic cleaner

  15. Back To Top    #15

    Join Date
    Jun 2013
    Location
    Orange County, NY
    Posts
    51

    Re: Should I lower my pH?

    I'm pretty sure the green tint has something to do with my well water. After shocking and being perfectly clear and clean for a week or two, I drained about 4" of water from the pool and re-filled with well water. The same green tinge came back! Then it just goes away by itself within 24 hours.

    What could be in my well water that is having this effect? It is a VERY VERY slight tinge of green, hardly noticeable but there.
    - Max
    __________________________________
    20k gal, inground vinyl, 1 1/2 HP Hayward SuperPump, HW Veriflow XL Sand Filter, Hayward Aqua Rite T-Cell-9, AquaComfort Heat Pump ACT-1100
    Hayward TigerShark robotic cleaner

  16. Back To Top    #16
    Mod Squad Bama Rambler's Avatar
    Join Date
    Jun 2009
    Location
    SouthWest Alabama
    Posts
    22,347

    Re: Should I lower my pH?

    A few people here have reported the same occurance. It's most likely metals and either enough of them are getting filtered out or they initially react to the chlorine.

    If you're still looking at replacing half of the water you can get a sump pump and a hose water meter and pump out a little more than the amount you want to replace and then have water trucked in.
    Dave J. TFP Moderator
    24' x 52" Round AGP. 2hp/¼hp SPL Power-Flo 2-speed pump. 200sqft Waterway Cartridge Filter. 45MHP2(3GPD) Stenner Peristaltic Pump
    Pool School ----- Pool Math ----- TF-Test Kit

  17. Back To Top    #17

    Join Date
    Jun 2013
    Location
    Orange County, NY
    Posts
    51

    Re: Should I lower my pH?

    Ahh.. hose water meter, that should do the trick.
    - Max
    __________________________________
    20k gal, inground vinyl, 1 1/2 HP Hayward SuperPump, HW Veriflow XL Sand Filter, Hayward Aqua Rite T-Cell-9, AquaComfort Heat Pump ACT-1100
    Hayward TigerShark robotic cleaner

Posting Permissions

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