Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 2 of 2

Thread: Overwinter CSI management

  1. Back To Top    #1
    Smykowski's Avatar
    Join Date
    Sep 2011
    Gurnee, IL (North Suburban Chi-town)

    Overwinter CSI management

    This is heading way out into the deep end, but I think it's relevant because we're in the middle of the springtime openers.

    Assuming you close the pool properly in the fall, how much do you need to worry about CSI and pH over the winter? How much of the pH change over the winter is due to the change in temperature and not due to a change in the underlying water characteristics? Does a very positive or very negative CSI have the same effect in very cold water as it does in warm water?

    I'm noticing that with no chemical changes and no aeration, my pH is rising as the temperature rises.

    The whole reason I ask is that we get many questions about adjusting pH over the winter and pouring acid under a cover. Is any of that even necessary? My get reaction is no, but I'd like some science to back it up.
    33' round, 23,000 gal AG vinyl , 1HP 2spd PowerFlo Matrix downsized with 3/4HP impeller (X2), Hayward S180T 150# sand filter (X2), Hayward H250 NG heater Pool Store year 1 - $850 for 2 months; Pool Store year 2 - $440 for 2 months, TFPC year 1 - $170 for 4 months; TFPC year 2 - $95 for 4.5 months
    The most important article on this site - The ABCs of Pool Water Chemistry

  2. Back To Top    #2
    JasonLion's Avatar
    Join Date
    May 2007
    Silver Spring, MD

    Re: Overwinter CSI management

    The CSI should remain essentially constant over the winter on it's own. The PH will go up as the temperature goes down, more or less canceling out any changes. The only significant exception is when fresh plaster is applied in the fall. In that case the plaster will still cure a little over the winter (not much) and that may require monitoring.
    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

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts