PH rising using alot of acid and not sure why


Jul 10, 2009
Topic Split off by Moderator

I'm putting about a Gallon of acid(31.45%) every two weeks in 13,000 gl pool - old plaster, SWG, Borates (50) - not getting used a lot yet this summer. Why is Ph climbing so fast?


TFP Expert
LifeTime Supporter
Jan 6, 2010
San Dimas, CA (LA County)
That actually sounds about right to me. Maybe a little high, but not much more than I use. First, I have hard water. If add 2" of fill water I have to add 2 cups of acid just to stay even on pH. Second, I have some real light calcium scaling that is slowly dissolving (we're talking months and months) by keeping pH down below 7.5 all the time. (and brushing with a steel brush) Third, I have to keep water flowing through the spa portion so it gets filtered, and there's no way to stop the bubbles. I have it down low, but it still gets a lot of aeration. Which isn't necessarily bad, as it gets rid of the TA. But it uses a bunch of acid.

Once the TA gets down to about 80, things stabilize quite a bit. But then it gets hot, water evaporates, I add more, and it all starts over again.