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Thread: Didn't know about CYA, added 13lbs of trichlor in 7 days

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    Didn't know about CYA, added 13lbs of trichlor in 7 days

    I have owned a pool for about a year. I always just had the 3inch tabs in the chlorinater and added liquid chlorine here and there. My pool would never turn green and I don't think it gets very dirty. There are few trees about, it is caged and it is surrounded by landscaping stones past the pavement. However, I went away for three months and the person caring for the pool did a poor job and it was green.

    I went to Walmart and bought "Pool Essentials Shock" which is 1lb bags of what says 53.8% Trichloro-s-triazinetrione and it says 48% available chlorine.

    After reading this website I now know that trichlor is to be avoided because it raises the CYA too high.

    When using the calculator, do you account for the "53.8%?", if you put one bag, is it 16x.538=8.6 ounces of Trichlor or is it just 16 ounces?

    My plan tomorrow is to go to the pool store and get a free pool test although I imagine the CYA will be very high and I will need to drain some water and add some more. I have read on here how unreliable the pool store tests can be. I also believe that my PH may be low from my reading here. What steps do I need to take and in which order to deal with the effects of high CYA and low PH? I do not want to trust the pool store.

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    JasonLion's Avatar
    Join Date
    May 2007
    Silver Spring, MD

    Re: Didn't know about CYA, added 13lbs of trichlor in 7 days

    Welcome to TFP!

    Because the tablets you are using are only 53.8% trichlor, a one lb bag only holds 8.6 oz of actual trichlor. The rest is filler.

    The first step is to get a complete set of water test results. The best way to do that is to get your own top quality test kit. With a good test kit you will get more reliable test results than you can get from the pool store. Without knowing what your numbers actually are we can't give you meaningful advice.
    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

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    Join Date
    Apr 2012
    SW Ohio

    Re: Didn't know about CYA, added 13lbs of trichlor in 7 days

    Agree with Jason lion.....100%
    18x52 intex ultra frame pool 6981 gallons, 1 HP LL pump with 19 in sand filter,BBB method,borax 50ppm
    leslies DPD test kit + fas-dpd chlorine test kit + borates test strips
    thru wall skimmer,hard plumbed with 2 returns 1 1/2 sch 40 pvc
    1 large fountain 1 inch sch 40 pvc,shut off ball valves on all

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