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Thread: Will CYA dissapate ?

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    Join Date
    Jun 2013
    Northern NJ

    Will CYA dissapate ?

    Hi, I know my cya level needs to be reduced by draining my pool by what the pool calculator tells me. But my question is: I am closing my pool in the next week or so. Will cya levels dissapate over the winter?
    36,000 gal IG vinyl. Haywood pump and heater Hayward DE filter blue diamond robot. Hayward Aqua Rite SWG AQR-15

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    BoDarville's Avatar
    Join Date
    Jun 2012
    DFW, Texas

    Re: Will CYA dissapate ?

    It is possible, but I wouldn't bet on it. In rare occasions, CYA can be degraded (consumed) by bacteria. Although there are several posts on the forum where users have experienced this, it is quite rare relative to the installed base of pools.

    If you want to read more about this, here is an article which goes into some technical details: Degradation of Cyanuric Acid (CYA)
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  3. Back To Top    #3
    Mod Squad zea3's Avatar
    Join Date
    Jul 2009
    Houston, Texas

    Re: Will CYA dissapate ?

    Hi, welcome to TFP! No, CYA will not dissipate over winter. There are some rare situations that cause CYA to be consumed, but for the most part if you close with CYA in the winter you will open with CYA in the spring.
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  4. Back To Top    #4
    Richard320's Avatar
    Join Date
    Jan 2010
    San Dimas, CA (LA County)

    Re: Will CYA dissapate ?

    That depends on what you mean by closing. If you live somewhere where it freezes and you drain below the skimmers when you close, it will get diluted in the spring when you refill. Or if the cover is porous and you get a lot of rain and snow. But don't count on it breaking down and disappearing.
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