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Thread: Need Help

  1. Back To Top    #1

    Join Date
    Sep 2009
    Spring, TX

    Need Help

    What can I use to lower TA and increase CH?


  2. Back To Top    #2
    dmanb2b's Avatar
    Join Date
    Apr 2009

    Re: Need Help

    It's in Pool School, but in case you missed it


    The acid/aeration process to lower TA:
    Lower your PH to between 7.0 and 7.2 with acid.

    Aerate until the PH goes up to 7.6.

    Repeat steps 1 and 2 until you reach the desired TA.

    You can lower PH with muriatic acid or dry acid/PH Reducer. You can get an estimate of the amount of acid to use with The Pool Calculator. Keep in mind that the amount of acid required can vary from the estimate. If your test kit includes the acid demand test, you can use that to calculate the amount of acid required more precisely. Allow at least 30 minutes after adding acid, with the pump running, before testing the PH again.

    Aeration can be provided by a SWG, spa jets, waterfall, fountain, return pointed up so it breaks the surface, air compressor, kids splashing, rain, etc. This post and this one show examples of home made fountains and this post shows a spa style jet that fits into a return.

    Lowering TA can take some time, days or even weeks, depending on the amount of aeration you have and how far you need to lower your TA. Many smaller bubbles are better than a few large bubbles. Lowering the PH back to 7.0-7.2 more frequently will also speed up the process, though that can get tedious.

    It is actually the acid which lowers TA. Adding acid lowers both the PH and the TA. Then aeration raises the PH without changing TA. Do not use chemicals to raise your pH during this procedure (unless your pH accidentally goes way too low); that will just raise your TA back up, which is exactly what you are trying to avoid.


    CH - Calcium Hardness

    Calcium hardness indicates the amount of calcium in the water. Over time, water with low calcium levels will tend to dissolve calcium out of plaster, pebble, tile, stone, concrete, and to some extent fiberglass surfaces. You can prevent this from happening by keeping the water saturated with calcium. In a vinyl lined pool there is no need for calcium, though high levels can still cause problems. A plaster pool should have CH levels between 250 and 350 if possible. Calcium helps fiberglass pools resist staining and cobalt spotting. If you have a spa you might want to keep CH at at least 100 to 150 to reduce foaming. CH contributes to the CSI which indicates the tendency for paster damage or calcium scaling.

    You increase CH with calcium chloride, sold as a deicer and by pool stores, or calcium chloride dihydrate, sold by pools stores for increasing calcium. You lower calcium by replacing water.
    24'x52" AGP (13,500 Gallons), Intex SWG, (2)Solar Bear 4x20 panels, Hayward S220T Filter, 1/2hp Pentair Superflo

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