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Thread: calcium hardness

  1. Back To Top    #1

    Join Date
    May 2008
    Location
    Texas
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    calcium hardness

    pool water
    CH 400
    TA 80

    I just tested my fill water and got these results:

    pH 7.8
    FC .5
    CC 2
    TA 200
    CH 350

    Will I ever be able to decrease the CH? If so, how??
    Never tested the fill water before, but wondering about the TA too. Is that normal for fill water?
    23,000 gal grecian vinyl IG with cover

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    JasonLion's Avatar
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    May 2007
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    Re: calcium hardness

    Having TA and CH that high in your fill water is not common but you do see things like that in some areas. You are going to need to let your CH level get fairly high to avoid refilling the pool all the time. At the same time you are going to need to replace water fairly regularly, because that is the only thing that will keep the CH level under control.

    The key to managing high CH fill water is to keep your PH and TA reasonably low at all times. That may get tricky with high TA fill water, but can be done.
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
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  3. Back To Top    #3

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    Re: calcium hardness

    Ok.
    So how high can I safely let that CH level get?
    And then, how low (or how much lower) should the TA and pH be??

    Is this just about maintaining a "balance" using what you've got? It's making me a little nervous...I don't want to eventually ruin something.

    Thank you for all your responses!
    23,000 gal grecian vinyl IG with cover

  4. Back To Top    #4
    Guest

    Re: calcium hardness

    Quote Originally Posted by SeaBass
    Ok.
    So how high can I safely let that CH level get?
    And then, how low (or how much lower) should the TA and pH be??

    Is this just about maintaining a "balance" using what you've got? It's making me a little nervous...I don't want to eventually ruin something.

    Thank you for all your responses!
    Some parts of the country have fill water with CH over 1000 ppm. The key is to lower TA and watch pH. CH of 350 is not that high and is, in fact, well within acceptable range. TA CAN be lowered but if your fill water has high TA it means that it is something you will need to keep on top of. Basically it means you work with what you have. The key to avoid problems in these cases is very 'tight' pH control. It might be a bit more work but it's not impossible.

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    Re: calcium hardness

    So, is it correct to say that I should just stay at the bottom of the recommended range for pH...like 7.2?
    23,000 gal grecian vinyl IG with cover

  6. Back To Top    #6
    JasonLion's Avatar
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    Re: calcium hardness

    Right now you are fine with PH between 7.2 and 7.8, but if TA and CH go up, as they are likely to do, you will need to tighten that range to 7.2-7.6 or even 7.2-7.4. It is possible to manage CH levels up to about 1,200, but that requires tight control over TA. With the TA level in your fill water you may need to have a lower CH limit. It depends on how well you can keep TA under control.

    As water evaporates you will be adding more water to the pool. The TA and CH originally in the pool don't evaporate, so adding new water will be raising your levels. You can lower TA using the lowerin TA procedure in this article. You don't need to do that right now, but if TA goes up much you will.
    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

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    Round Rock, TX
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    Re: calcium hardness

    Funny thing, I saw your number and thought "Wow must be from Texas".

    I have the same fill water "qualities". My CH is 650 and TA is 210. I keep my pool at CH 650, TA 80-90 and PH between 7.2 and 7.8.

    I found that if I don't keep my TA in that range the PH goes off the charts fast. I've become very good at adding muriatic acid and aerating the pool. I do it every time I add water to the pool, which is every week or so.

    dave
    15,500 gal, inground gunite pool with 7 ft spa, 2 speed pump 2hp/.33hp, 3/4 hp booster pump, Intermatic P1353 timer, AutoPilot SC-48, Sand filter with ZeoBest, Heater, that I never use . . .

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