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Thread: Calcium Hardness increasing

  1. Back To Top    #1

    Join Date
    Aug 2012
    Location
    Brisbane , Australia
    Posts
    54

    Calcium Hardness increasing

    My latest results

    PH 7.5
    FC 3.5 (will adjust that to 6 with bleach )
    TA 90
    CH 480
    CYA 90

    The pool calculator is reading as balanced, but the calcium keeps increasing. I don't want to remove water as it's too expensive in Brisbane to keep refilling.

    Is this high reading a concern and I have read about chemicals that reduce calcium. ie: Zodiac Calcium Down

    Cheers
    19,000 gallons
    Zodiac Tri Series SWG
    Hayward S310T Sand Filter
    Poolrite SQI 600 pump.
    IG Concrete, quartzon surface
    Built 1997

  2. Back To Top    #2
    Richard320's Avatar
    Join Date
    Jan 2010
    Location
    San Dimas, CA (LA County)
    Posts
    18,768

    Re: Calcium Hardness increasing

    480? Hah! Try 825. I've actually gone as high as 1100 before.

    If you got that reading by hand-swirling, it's probably reading higher than reality. My CH dropped a couple hundred points when I went to using a speedstir. Also, when you get into that range, use the extended directions and 10ml water. Does it matter if it reads 475, 480, or 500? Not really. But it does save reagent, and a lot of time.

    I keep the pH below 7.5 and the TA below 70 and that keeps my CSI negative, so it actually is slooooooooowly lifting scale, not just preventing it.

    I have a hose fitting on my return pipe, which has made it really easy to use pool water on the lawn. And then I replenish with lower CH tap water. Same water used, it just gets run through the pool. I don't know how the salt will affect things, though, since I use jugs of bleach and you have a SWG.

    I have zero firsthand experience with Calcium sequestrants. You might try searching that term here and see what comes up.
    16K freeform gunite with spa; Pentair 4000 DE filter; Century Whisperflow 1 HP; Pentair Minimax heater.
    Troublefree does not mean Maintenancefree. It's like brushing your teeth: You can spend a couple minutes a day and pennies a week or go to the dentist once a year and spend several thousand dollars.
    A pool is like a pet - you have to feed it every day, even the days you don't want to play with it!

  3. Back To Top    #3

    Join Date
    Feb 2008
    Location
    Denton, TX
    Posts
    5,061

    Re: Calcium Hardness increasing

    Yes, Richard320 is proof-positive that one can manage to keep the water balanced despite having an extraordinarily high calcium hardness. By managing your CSI correctly, you can remain scale free. Take a look at pool-school/calcium_scaling for more information on this.

    Have you checked to see what the source of your rising calcium might be? If you are using calcium hypochlorite, you should stop since that raises your CH every time that you use it. How about your fill water? Have you checked to see what the CH is on your fill water? It might surprise you as to how high it is.

  4. Back To Top    #4

    Join Date
    Aug 2012
    Location
    Brisbane , Australia
    Posts
    54

    Re: Calcium Hardness increasing

    Thanks. I won't panic just yet. I'm not using Calcium Hypochlorate. I have no idea why it is rising. We have had a lot of storms lately that added about 4 or 5 inches to the pool. It's still looking pretty good so I'll keep it balanced and see what the coming months hold
    Cheers
    19,000 gallons
    Zodiac Tri Series SWG
    Hayward S310T Sand Filter
    Poolrite SQI 600 pump.
    IG Concrete, quartzon surface
    Built 1997

  5. Back To Top    #5

    Join Date
    Feb 2008
    Location
    Denton, TX
    Posts
    5,061

    Re: Calcium Hardness increasing

    Well, if the water that you use to fill and top off the pool has a high calcium hardness, then that is probably where it is coming from.

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