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Thread: CYA 3rd day--shows too high

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    CYA 3rd day--shows too high

    reads cya of 55 on taylor TF-100 kit. With new well water, pool math showed to add 67oz so I added 64oz 3 days ago. Is it apt to go up or down in a weeks time?
    anyways, here are the other numbers,

    fc--2
    cc--0
    tc--2
    cl--3
    ph--7.2
    ta--130
    cya-55
    12,500 gal. AG---extruded alum. with 1hp Hayward EC-50, D.E. filter ( both 30 yrs. old)--Taylor TF-100---well water

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    Richard320's Avatar
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    Re: CYA 3rd day--shows too high

    55 CYA is fine. Unless you were targeting 40, then there is some kind of problem, either with the pool volume or with your testing.

    The test itself is pretty subjective, and the readings can change quite a bit just depending on the light. If I hold the view tube naturally, it reads different than if I just hold the very top between thumb and forefinger.

    CYA should stay pretty consistent after it's been dissolved and had time to completely mix with the pool water. You'll lose a little bit over time to splashout and backwashing.
    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!

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    Re: CYA 3rd day--shows too high

    Thank you for responding.
    As suggested, I targeted 40 cya for this pool, so if 55 is fine, that would be great!
    But also, I don't fully understand what to do about the 3 chlorine numbers I showed above. I'd appreciate some advice.
    12,500 gal. AG---extruded alum. with 1hp Hayward EC-50, D.E. filter ( both 30 yrs. old)--Taylor TF-100---well water

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    Re: CYA 3rd day--shows too high

    Your FC is WAY too low for a CYA of 60 (round up). Pool School - Chlorine / CYA Chart
    32K gallon Plaster - 1hp Hayward 2 speed Super Pump - Hayward S200 Sand Filter - TF100XL
    Test Kits - Pool Math - Chlorine/CYA/Target/Slam Chart

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    Re: CYA 3rd day--shows too high

    Quote Originally Posted by jmart View Post
    Thank you for responding.
    As suggested, I targeted 40 cya for this pool, so if 55 is fine, that would be great!
    But also, I don't fully understand what to do about the 3 chlorine numbers I showed above. I'd appreciate some advice.
    If you go to poolmath and down in the last row select your methods and pool material, it will autofill suggested values.

    It will give you a range for FC, like 4-9. 4 is the absolute minimum to which you should ever let the FC drop. What you choose as a target depends on how much you lose every day. Every pool is different, depending on sunlight, bather load, how much debris falls in, dogs swimming, whatever. You will quickly learn by daily testing just how much you lose.
    So... let's say you target 9. The next day you find you have 6.5 FC left before you dose again. That's above 4, so you can aim a little lower. So you target 8. The next day maybe you're at 6. So you target 7. And maybe you end up at 4.5. That's above 4, but cutting it pretty close. So you might want to target 7.5. In a few weeks you'll know pretty much exactly how much bleach to add every day, and can even guess your test results with amazing accuracy before you start. Just test and dose and pay attention and it will suddenly all make sense.
    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!

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    Re: CYA 3rd day--shows too high

    So according to pool math, I targed my fc to be 7 and the recommendation was to add 104oz of bleach. Does that sound correct? and that will take care of the cc and tc numbers right?
    12,500 gal. AG---extruded alum. with 1hp Hayward EC-50, D.E. filter ( both 30 yrs. old)--Taylor TF-100---well water

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    Re: CYA 3rd day--shows too high

    I get 93 oz of 8.25% so close enough.

    Correct!
    32K gallon Plaster - 1hp Hayward 2 speed Super Pump - Hayward S200 Sand Filter - TF100XL
    Test Kits - Pool Math - Chlorine/CYA/Target/Slam Chart

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    Re: CYA 3rd day--shows too high

    OK, great. So my plan is to add 104oz of bleach now ( I'll dbl check the math) and then I'll check the numbers daily until I have a better understanding of it. Thanks for the confidence everyone. Jerry
    12,500 gal. AG---extruded alum. with 1hp Hayward EC-50, D.E. filter ( both 30 yrs. old)--Taylor TF-100---well water

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    Re: CYA 3rd day--shows too high

    So it's been 2 days and the water looks great.
    Today's results:
    FC--7.5
    CC--0
    PH--7.5
    TA--125
    CH--25
    CYA-55
    So with a PH target of 7.7, pool math suggests adding 22oz borax which I'm about to do.
    My plan now is to do the chlorine drop test daily until I get a handle on it and all other tests weekly.
    Is this the correct approach?
    Last edited by jmart; 06-12-2016 at 06:44 AM. Reason: added more info
    12,500 gal. AG---extruded alum. with 1hp Hayward EC-50, D.E. filter ( both 30 yrs. old)--Taylor TF-100---well water

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    Re: CYA 3rd day--shows too high

    Hold off on raising pH. There is nothing wrong with 7.5. It may rise on its own.

    Do pH every time you do chlorine too. And yes, the other tests can be weekly.

    Nice job!
    32K gallon Plaster - 1hp Hayward 2 speed Super Pump - Hayward S200 Sand Filter - TF100XL
    Test Kits - Pool Math - Chlorine/CYA/Target/Slam Chart

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    Re: CYA 3rd day--shows too high

    OK Mr Bruce, I'll take your advice and continue to monitor as you suggested, thank you,-- Jerry.
    Last edited by jmart; 06-12-2016 at 07:39 AM. Reason: grammar
    12,500 gal. AG---extruded alum. with 1hp Hayward EC-50, D.E. filter ( both 30 yrs. old)--Taylor TF-100---well water

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    Re: CYA 3rd day--shows too high

    Mr. Bruce is surely correct. My pH is hovering at 7.2 and I will let it ride!
    Pool installed 8/2015. 30' round Radiant pool. 21,000 gallons. 200# sand. Hayward Vari flow XL valve. 1.5hp Hayward Power-Flo Matrix running 10 hours/day in two periods. TF100 with speed stir. Sun all day, south side of house
    Order test kit TF-100 w/ Speed Stir and then Poolmath Calculator --- RECOMMENDED LEVELS --- POOL SCHOOL --- Algae? --- Chlorine/CYA CHART.

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    Re: CYA 3rd day--shows too high

    Great! thanks guys, I'm starting to think that I can do this.
    12,500 gal. AG---extruded alum. with 1hp Hayward EC-50, D.E. filter ( both 30 yrs. old)--Taylor TF-100---well water

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    Re: CYA 3rd day--shows too high

    you can, stick around here, I'm new but this is easy!
    Pool installed 8/2015. 30' round Radiant pool. 21,000 gallons. 200# sand. Hayward Vari flow XL valve. 1.5hp Hayward Power-Flo Matrix running 10 hours/day in two periods. TF100 with speed stir. Sun all day, south side of house
    Order test kit TF-100 w/ Speed Stir and then Poolmath Calculator --- RECOMMENDED LEVELS --- POOL SCHOOL --- Algae? --- Chlorine/CYA CHART.

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