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Thread: Opening water balance question...

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    Opening water balance question...

    This is not so much about how to get levels where they should be (finally did that today!!!! yay!!!), but more about why they were where they were.

    This is the first year our pool has been such a bear to 'get right' (our 4th season opening it). In the past, we just had to shock it in spring, and then light maintenance to keep it in line. Chlorine wasn't really an issue - 4 big jugs of bleach, 3 lbs. of shock, and opening the feeder full throttle got that taken care of. But this year, pH, TA, and CYA dropped essentially to zero over the winter. It took 15 lbs. of borax, 30 lbs. of baking soda, 6 lbs. of "pH UP", and 5 lbs. of stabilizer to get in the 'comfy' zones.

    It has blued up nicely, and is starting to become un-cloudy. All tests are now in the sweet spots.

    What could cause such a big difference year over year? We didn't (and have never) winter-cover it, and the water was balanced the last time tested before it got too cold to dip a hand in it. The only thing I can think of that was different was that we were about 3 weeks later opening due to fixing a bad multi-port.

    Any ideas? Why did it get so acidic? Where did all the CYA go? I don't want a repeat of this next year - it was a pain!



    P.S. Yay! Pool is blue!
    16 x 36 vinyl in-ground, Sta-Rite Cristal-Flo T-240BP1 sand filter, Centurion 1hp pump, PentAir Model 320 in-line feeder

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

    Re: Opening water balance question...

    CYA can disappear over the winter sometimes. We think that happens because it gets consumed by certain kinds of soil bacteria. When this happens there is often, but not always, ammonia left in the water that needs to be broken down by lots of chlorine before the pool will hold an FC level.

    The PH falling like that is much less common, and I don't really have a confident guess at what might have happened. Using a chlorine tablet feeder without adding something to bring the PH back up can lower the PH quite dramatically, but that would have had to happen while the pool was open and would have taken a while.
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
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    Mod Squad zea3's Avatar
    Join Date
    Jul 2009
    Houston, Texas

    Re: Opening water balance question...

    What part of the country are you in? There are a handful of our forum users who report their CYA drops to 0 every winter without having the bacteria problem that consumes CYA and leaves ammonia in the water. No one knows why it happens. Did you have a lot of snow or rain that could have displaced the pool water over the winter?
    TFP Moderator
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    Vogue 21' round AG, Pentair 1 hp 2 speed pump, 36 sq ft DE filter, Hayward S180T 150# sand filter, Houston, Texas
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    Re: Opening water balance question...

    West TN, just outside of Memphis. Rain / snow were about the same as last year. I think I sumped out about 6 inches of water back in February when we started getting (really cold!) rain that brought the water level up to the skimmer.

    For now I'm just writing it off as one of those 'things'. Once I get it shut down, is there really anything I can do to keep the water balanced with no pump circulation? As fun as it sounds, I'd rather not be out there in December stirring in chemicals with the vacuum pole and a leaf net.
    16 x 36 vinyl in-ground, Sta-Rite Cristal-Flo T-240BP1 sand filter, Centurion 1hp pump, PentAir Model 320 in-line feeder

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