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Thread: CYA stable or going down?

  1. Back To Top    #1

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    CYA stable or going down?

    Triggered by a remark of chemgeek in post Foam that isn't?
    "By the way, don't forget to use Dichlor one day each month to help maintain the CYA level. You might test for the CYA level to be sure it's not too low. Chlorine slowly oxidizes CYA in hot tubs at the rate of roughly 5 ppm per month."

    I was wondering if the sticky "How do I use Chlorine in my Spa (or pool)?" would need a remark about degrading CYA?
    Until now i was under the assumption that CYA would last the water renuwal periode but now i'm wondering. If i understand it correctly than CYA would go lower in the period of time. So starting at 30 would mean about 25 at the end of the month.
    A wise man would say: why not now meassure CYA, and he is so right. BUT in holland the summer is over so it would be very hard to get the optimal sun conditions to do a good CYA measurement
    So perhaps next best thing (to keep cover allright) would be to add an amount of stabilizer each month to compensate for CYA loss.
    For my spa i guess about 0.3oz (9 gram) of stabilizer (478gallon/FC 4/PH7.5/TA50/CH150/Borate50/temp102)
    Or do i miss something?

    regards,
    edwin
    Arctic Spa Klondike Legend SE
    AG / Filter Cardtrige 50m2/ TFP / borates / TF100
    478 gallon @ 99.5-103.1 F Depending on season
    Ozonator disconnected

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    Re: CYA stable or going down?

    you could possibly order the 50 PPM CYA reference liquid. Then put together whatever artificial, repeatable light arrangement within your house so that you are reading 50 with the reference vial. Then you can use that same lighting going forward with confidence.
    10,500 gal IG, Topaz Pebble, auto-level
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    Re: CYA stable or going down?

    He is in The Netherlands and can't order from TFTestkits unless he has someone get it for him or makes a trip over here. Once your pool water temp reaches below 60 F or 15.5 C, the FC demand will drop and will continue to do as the water temp drops. I hope this helps.
    5900 G Fiberglass IG pool (circa 1990), SWG Hayward Aqua Rite GoldLine (2013), IntelliFlo Variable Speed Pump (2013), Hayward Pro Sand Filter (circa 1990), Well water (no iron or other metals fortunately), test with Taylor K2006C, Charleston, SC

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    Re: CYA stable or going down?

    Will the reference liquid also work for CYA of 30?
    Could take it with me next time I'm in the states.
    Arctic Spa Klondike Legend SE
    AG / Filter Cardtrige 50m2/ TFP / borates / TF100
    478 gallon @ 99.5-103.1 F Depending on season
    Ozonator disconnected

  5. Back To Top    #5

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    Re: CYA stable or going down?

    The reference liquid is a test to make sure you can accurately measure CYA using the TF 100 or Taylor K2006 test kit. If you read the reference test at 50, you are doing the test accurately. If not, you need to change something in your test until you accurately read 50 eg. light, distance, mixing etc.
    5900 G Fiberglass IG pool (circa 1990), SWG Hayward Aqua Rite GoldLine (2013), IntelliFlo Variable Speed Pump (2013), Hayward Pro Sand Filter (circa 1990), Well water (no iron or other metals fortunately), test with Taylor K2006C, Charleston, SC

  6. Back To Top    #6

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    Re: CYA stable or going down?

    Yes, the sticky should refer to dosing with Dichlor about one day per month (about 6 ppm FC worth). While testing for CYA would be ideal, just adding Dichlor one day per month should be OK since the degradation rate is fairly slow.
    16,000 gallon outdoor in-ground 16'x32' plaster pool; Pentair Intelliflo VF pump; Pentair IntelliTouch i9+3s control system; Jandy CL-340 square foot cartridge filter
    12 Fafco solar panels; Purex Triton PowerMax 250 natural gas heater (200,000 BTU/hr output); automatic electric pool safety cover; 4-wheel pressure-side "The Pool Cleaner"

  7. Back To Top    #7

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    Re: CYA stable or going down?

    not sure which dichlor i need. For CYA add's i use the Pool Stabilizer from melpool. So i guess i'm somewher in the ball park if i add 0.3oz (9 gram) each month until the bright sun return's.
    Arctic Spa Klondike Legend SE
    AG / Filter Cardtrige 50m2/ TFP / borates / TF100
    478 gallon @ 99.5-103.1 F Depending on season
    Ozonator disconnected

  8. Back To Top    #8

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    Re: CYA stable or going down?

    Sure, you can use Pool Stabilizer if you want. You don't need to use Dichlor. You want to add around 5 ppm CYA per month though after a couple of months you can test the CYA to see if you are indeed losing around 5 ppm per month. So yes, 9 grams (0.32 ounces weight) in 478 gallons would be 5 ppm CYA.
    16,000 gallon outdoor in-ground 16'x32' plaster pool; Pentair Intelliflo VF pump; Pentair IntelliTouch i9+3s control system; Jandy CL-340 square foot cartridge filter
    12 Fafco solar panels; Purex Triton PowerMax 250 natural gas heater (200,000 BTU/hr output); automatic electric pool safety cover; 4-wheel pressure-side "The Pool Cleaner"

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