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Thread: Welcome to MH....High Calcium

  1. Back To Top    #1
    dmanb2b's Avatar
    Join Date
    Apr 2009

    Welcome to MH....High Calcium

    Posting PM received from MH

    Message subject: HIGH Calcium hardness Sent: May 21st, 2010, 12:04 am
    Quote Originally Posted by MH
    I'm a new pool owner in Goodyear, AZ (20 mile west of Phoenix; the western edge of civilization). I just got my Taylor #2004B test kit. Here are the readings:

    pH: 7.6
    FC: 1
    TA: 200
    CH: 600+
    CYA: 120
    CYAf: 160

    I say CH is 600+ because I got tired of adding drops after 60. Emptying the pool and refilling won’t help much because my city water measures 475 ppm and I have to add water often. Is there another good option to reduce calcium hardness?
    Also, with a Pentair Triton II TR100, what should my pressure be after backwashing? Currently, it is 0.


    20K gallons, Plaster, 1.65 SFHP, Pentair Triton II TR100 30” sand 74 GPM, 6.5 hours circulation, K-2005 test kit, Zodiac Barracuda G3
    24'x52" AGP (13,500 Gallons), Intex SWG, (2)Solar Bear 4x20 panels, Hayward S220T Filter, 1/2hp Pentair Superflo

    Pool School, TFTestKits, Pool Calculator

  2. Back To Top    #2

    Join Date
    Feb 2008
    Denton, TX

    Re: Welcome to MH....High Calcium

    Welcome MH to TFP!

    Our members that live in the desert southwest do have some options at their disposal that can help with high CH levels.

    One of these options is to have a reverse osmosis service come out to service your pool water. Using a sophisticated trailer-mounted system, they are able to process your pool water on site and remove things such as calcium and CYA from the water. This is nice because there is no draining the pool to replace water. Only the contaminants are removed. The downside to this is that the service can be expensive to some people and unless you have the ability to top-off your pool with softened water, your CH will eventually rise again due to the innate hardness of the fill water in the area.

    Others however have learned to live with high CH levels to some degree by making adjustments in other water chemistry components that make having a high CH much less of a problem. The issue with high CH really comes down to scaling, but scaling occurs when a combination of things permits an environment to be conducive to the scaling process and some of these can be readily controlled by yourself independently of CH. For example, your TA is very high. By lowering this number, you can dramatically reduce your pool's propensity to scale. Your pH can also be reduced, thereby lowering the propensity to scale. Each of these levels contribute to an overall measurement called the Calcium Saturation Index or CSI. The CSI is a scaling/corrosion risk analysis tool and is pretty accurate when it comes to down to it.

    You can use the Pool Calculator (link in my sig line) to see what adjustments you can make to bring your CSI down and reduce scaling potential. The factors that influence scaling risk are CH, TA, pH, temperature, and borates.

    I'd like to suggest some links here to help you get started and will list them below. As it stands also, your FC is much too low and you are liable to end up with algae unless you lower your CYA significantly. At 120, your CYA is much, much too high. If you opt to go with a reverse osmosis service, they can also remove CYA with this process as well.

    ABC's of Pool Water Chemistry

    Recommended Levels

    Lowering Total Alkalinity

  3. Back To Top    #3
    coog61's Avatar
    Join Date
    Nov 2009
    Richmond, TX

    Re: Welcome to MH....High Calcium

    In regards to testing for CH, a small magnetic stirrer is the way to go (see discussion - Also for high CH, there are posts on the site that recommend cutting the the water sample and test chemicals by 50% to get the approximate results in less time and effort.
    17,500 Gallon, SWG 33' x 21' freeform w/ Sunstone Cobalt Plaster. Attached 6 X 6 Spa raised 12" w/ 6 Jets with Moss Rock Spillover. 25' Moss Rock Waterfall. Pentair Intelliflo VS-3050 for Pool, 2 HP Whisperflo for Waterfall, Pentair Clean & Clear Cartridge 320, Pentair 400K BTU Max-E-Therm heater, Pentair Intellichor, Pentair EasyTouch 4P, Pentair Legend Platinum Cleaner w/ 3/4 hp pump, autofill system, nat gas fire pit. BBB convert

  4. Back To Top    #4

    Join Date
    Feb 2008
    Denton, TX

    Re: Welcome to MH....High Calcium

    Quote Originally Posted by coog61
    Also for high CH, there are posts on the site that recommend cutting the the water sample and test chemicals by 50% to get the approximate results in less time and effort.
    Good point. Yes, when you suspect that your CH is high, you can do the high concentration version of the test which is:

    1. Use a 10 ml water sample
    2. 10 drops of the R-0010
    3. 3 drops of the R-0011L
    4. And then start adding your R-0012 dropwise until you observe a color change from pink to blue. Add up the number of drops of R-0012 to get to the endpoint and multiply the number by 25 for your result.

  5. Back To Top    #5

    Re: Welcome to MH....High Calcium

    Without sounding like an ad (honestly! And I don't go to AZ anyway!), R/O can take the levels down to 100-150 pretty easy, and if ran long enough, nearly to zero. Even adding high CH level water back would take quite a while to get back out of "acceptable levels". I would be guessing at this point, but it could take a good couple years to get out of range if they lowered it far enough.

    There is a good R/O outfit in Phoenix that I might be able to refer. PM me if you like and I will get you their info.

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