Chlorine at 0 and High TA


In The Industry
May 6, 2021
Hi all, new pool owner and have been struggling with chlorine continuing to drop to 0 and water getting cloudy. I've added shock but I don't think I'm adding enough to ACTUALLY SLAM so wanted to verify before I do this as the chlorine level to bring it to seems awfully high.

Latest test results with Taylor test kit:
FC 0.0 (test stayed clear/didn't turn pink)
pH 7.4
TA 275
CH 275
CYA 80

it's a 20'x44' inground pool which I think is around 31000 gallons. I believe I need to get my pH down to about 7.0 (which I think is about 2 gallons of MA) to drop TA and then aerate to get pH back up into range without raising TA.

Water is very cloudy (but not green) in both shallow and deep (we were just swimming last night and noticed it was starting to get cloudy but overall still looked pretty good).

If FC is 0 (and has dropped to 0 before) and water is cloudy, does that mean I should SLAM? And if so, am I really raising the chlorine level to 31 and putting in almost 8 gallons of shock @ 12.5%? My only worry before i do this is since my CYA level is good that chlorine level will hold for awhile right?

Appreciate the help!
Last edited:

Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
Jun 22, 2014
Texas, San Antonio/Marion, South-Central Area
Pool Size
Salt Water Generator
SWG Type
CircuPool RJ-45 Plus
Welcome to TFP! :wave: I wouldn't worry about the TA right now. A SLAM Process appears to be #1 on the plate right now. Of course you do have the option of exchanging some water to lower the CYA before starting the SLAM if you wish that would require a lower SLAM FC level, but if you are comfortable with the FC level of 31 that's fine as well. Your pH is right on the border of where we recommend for starting a SLAM. If you wish to lower the pH, you only need to go down to about 7.2, so not much. But follow the SLAM page and you should do fine. Let us know if you have any questions.


Bronze Supporter
Apr 16, 2019
Bremen, GA, 65 m west of Atlanta
Pool Size
Liquid Chlorine
Be sure to read (or reread) the SLAM Process article before you start. pH should be about 7.2, and on the first day you need to test often and add chlorine often. A SLAM is most definitely not a one and done process!

If you can, test every 2 to 4 hrs on the first day. Then, depending on how your pool looks, you can back that down to 4 times a day, then twice a day as your chlorine starts to hold. Pass OCLT, CC<=0.5, and crystal clear water means you're done!


Mod Squad
LifeTime Supporter
Jan 17, 2012
Evans, Georgia
How did your stabilizer (CYA) level get so high??? HOW are (were?) you chlorinating your pool??

What do you do in the pool industry?

Maddie 🌻
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