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Thread: Will Borax cause a rise in CH?

  1. Back To Top    #1

    Join Date
    Jun 2016
    Osawatomie, KS

    Will Borax cause a rise in CH?

    I am adding borates to my pool. All my local store had was 5 boxes of 20 mule team, so I decided to buy them and see how it tested afterwards (went from o borates to 15).

    After I added them, my CH, which was testing at about 250, now tests at 450. I've looked high and low in the forums and on the web, and I don't see any warning or discussion of Borax driving up CH.

    Before someone suggests it, I have been a pool owner for 20 years. I do my own testing with a Taylor 2005 kit (and an additional TFT FAS kit). I don't think it's in my test methods (but I've made mistakes before).

    I really don't want to draw down the pool to lower the CH. I've been gradually getting the CYA where I want it through a slow addition of dry acid.

    AFWIW, I will do the rest of the borate addition through boric acid, via DudaDeisel. This is the only way to go. Less of the boric product, and no hassle of Muriatic acid.
    My Pool: 26,000 vinyl, CircuPool RJ-45 SWG, Pentair Variable Speed Pump, Pentair 420 Cartridge Filter, Polaris 360 w/booster pump

  2. Back To Top    #2
    TFP Guide
    Mr Bruce's Avatar
    Join Date
    Mar 2014
    Greenville, SC

    Re: Will Borax cause a rise in CH?

    Short answer, no.

    Is it possible you used a 25ml sample and counted by 10s?

    35K gallon Krystle Krete (Plaster) - Sand Filter - TF100
    Test Kits - Pool Math - Chlorine/CYA/Target/Slam Chart

  3. Back To Top    #3
    JoyfulNoise's Avatar
    Join Date
    May 2015
    Tucson, AZ

    Re: Will Borax cause a rise in CH?

    There is no calcium in Borax therefore it cannot raise your calcium hardness. It must be something in your testing methodology.

    What chemical is listed on the box?
    16k IG PebbleTec pool, 650gal spa, spillway and waterfall, 3HP IntelliFlo VS / 1.5HP WhisperFlo, Pentair QuadDE-100 filter, IC40 SWCG, MasterTemp 400k BTU/hr NG heater, KreepyKrauly suction-side cleaner, EasyTouch controls, city water, K-1001, K-2006 and K-1766 test kits, Mannitol test for borates

  4. Back To Top    #4

    Join Date
    May 2016
    Troy IL

    Re: Will Borax cause a rise in CH?

    In my experience, i think it can actually lower your calcium by causing some of it to precipitate and get filtered out of the water (or stuck to tile) due to the high pH of the stuff and the high concentration of it in the water immediately around the area you dump it into your pool.

    Of course, a little bit of borax isn't going to change it much. Probably not enough to even notice on a test.

    20,000 gallon IG Vinyl
    Pentair Tagelus TA60D Sand filter
    Pentair Challenger 1.5HP pump CFII N1 1.5A
    Taylor K-2006-A, Stenner 45MPHP10 auto chlorine feed

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