Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 6 of 6

Thread: Falling Alk in a SWG Pool

  1. Back To Top    #1
    texasbrew's Avatar
    Join Date
    Aug 2007
    Location
    Humble, TX
    Posts
    50

    Falling Alk in a SWG Pool

    I am having problems with constantly falling ALK in my pool. I am using a SWG. I am adding acid almost daily at a rate of 16 to 20 ozs per the Pool Calc for the Iphone. I am only dropping my PH to 7.4 from whatever the reading is that day for the PH and ALK. I am currently sitting at 70 and I will probably add 2 lbs of baking soda before I leave town to get the ALK up to 80. Does anybody have any ideas as to what may be causing the ALK to drop? I have a bubbler on the sunshelf but I thought that would only come into play if the PH dropped to around 6.8. My CH is 550.




    Thanks-
    PG-500, WSM, 20K Gal gun pool w/ Aqua Pure 1400 SWG, flagstone coping, gray plaster, DE Filter, 400K BTU nat gas heater and Polaris 280 cleaner

  2. Back To Top    #2
    svenpup's Avatar
    Join Date
    Nov 2009
    Location
    Sacramento, CA
    Posts
    835

    Re: Falling Alk in a SWG Pool

    How high do you let the pH get before you add acid?

    You could let the TA drop to around 60, and let your pH get up to 7.8 and see how long it takes to get 8.0. Then try to keep it around 7.8 instead of constantly trying to get it down to 7.4

    The problem is that SWCG along with high TA is going to make you pH rise. If you try to overly constrain pH, TA drops along with it. Then you bump up the TA and the issue continues. I have seen several of the Mods here say that they keep their TA at 60 and their pH levels off at 7.7 - 7.8
    TFP Method Advanced Intermediate
    • 17,500 gallons - In Ground - Plaster - Hayward Swimclear 3020 Cartridge Filter - Sta-Rite Max-E-Glas Main Pump upgraded with A.O. Smith B2980 E-Plus New Centurion Two-Speed Motor - Polaris 280 Cleaner with Polaris PB4-60 Booster Pump - TightWatt2 Timer - Taylor K-2006 Test Kit - Pool Pilot Digital Nano SWCG

    Helpful Links: Pool School, BBB for Beginners, How to Shock (hint...it's a process not a product), Chlorine/CYA Chart, Jason's Pool Calculator

  3. Back To Top    #3
    Mod Squad Bama Rambler's Avatar
    Join Date
    Jun 2009
    Location
    SouthWest Alabama
    Posts
    22,333

    Re: Falling Alk in a SWG Pool

    Does it stabilize at 70 or does it drop down any lower? I wouldn't keep fighting it if it does.
    Also a lot of pools like the pH to be 7.8. If you leave it alone once it gets to 7.8 does it keep rising? If it doesn't then that may be your sweet spot.
    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

  4. Back To Top    #4
    texasbrew's Avatar
    Join Date
    Aug 2007
    Location
    Humble, TX
    Posts
    50

    Re: Falling Alk in a SWG Pool

    I try to keep the PH between 7.6 and 7.4 because of the CH being at 550. It does seem to sneak up on 7.8 on occasion. I will let the TA fall to wherever it wants to go I suppose but I was concerned that it might want to keep going much lower than 60.


    Thanks-
    PG-500, WSM, 20K Gal gun pool w/ Aqua Pure 1400 SWG, flagstone coping, gray plaster, DE Filter, 400K BTU nat gas heater and Polaris 280 cleaner

  5. Back To Top    #5
    texasbrew's Avatar
    Join Date
    Aug 2007
    Location
    Humble, TX
    Posts
    50

    Re: Falling Alk in a SWG Pool

    If I don't stay on top of the acid it will go off of the scale on the PH (I am using the TFTestkit).

    Thanks-
    PG-500, WSM, 20K Gal gun pool w/ Aqua Pure 1400 SWG, flagstone coping, gray plaster, DE Filter, 400K BTU nat gas heater and Polaris 280 cleaner

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

    Re: Falling Alk in a SWG Pool

    The PH is going up because TA is too high. You can let the TA come down to 60 and that will help a fair bit. To get the PH to stabilize as low as 7.6, you may need to lower the TA below 60. You should only let TA go below 60 if you have borates in the water. The borates will help stabilize the PH so that a lower TA level (down to 40) is alright.
    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

Posting Permissions

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