Lower TA When Pool Heated?


Gold Supporter
Silver Supporter
Nov 7, 2018
Oklahoma City, OK
For the most part, our pool stays balanced with little intervention required. I have to add about 4c of acid every couple of weeks to push down the PH. The pool has been cooling down and since we are having an Oktoberfest get together this weekend we decided to "hot tub" the pool. My weekly current numbers are a OK but....

Current #'s:

FC 5.0
CC 0.0
PH 7.8
CH 275
TA 50
CYA 60
Salt 3400
CSI -0.23

When I put in the same numbers with a temp of 65, I get a CSI of -0.54 which is not desirable but I am not going to do anything until it cools off in a few days and I re-test. Guess just looking for a little education. Thanks all!

Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
Your current numbers are okay, but I wouldn't let the TA get any lower. As you already know, when you kick-up the water temp, your CSI will increase closer to neutral. But when temps get lower, so will the CSI. Letting the pH rise or fall as needed will be your quickest and easiest method of adjusting CSI during this awkward time. But remember that the CSI isn't a huge factor if you're talking about only a few days or a week or two. The CSI has to be out of whack for several weeks or months to really begin to impact the pool's surface.