CSI vs PH

Frank in FL

Well-known member
Jul 3, 2019
326
Florida
Whats more important. Your CSI or PH level?

Using pool math, I see that the PH has a significant value to what your CSI ends up being. Based on my chemical levels, my PH needs to be between 7.6 and 7.8 to have a CSI of -.15 to +.03
 

Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
Frank, in almost all cases we will recommend sticking to the TFP Recommended Levels first,,, and the CSI will work itself out. In some cases, CSI becomes a bit more of a priority, but if you maintain good levels across the board, you should be fine. But you are correct, pH creates the largest and quickest swing of CSI.
 
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Frank in FL

Well-known member
Jul 3, 2019
326
Florida
Frank, in almost all cases we will recommend sticking to the FP Recommended Levels first,,, and the CSI will work itself out. In some cases, CSI becomes a bit more of a priority, but if you maintain good levels across the board, you should be fine. But you are correct, pH creates the largest and quickest swing of CSI.
Whats the "FP Levels?"
I was finally able to get my Alk down to 70. Thats after (2) 65 oz doses of acid .

Now Im at
FC 6
PH 7.2
ALK 70
CYA 80
Hardness 500
Salt 3400
This gives me a CSI of -.51 :eek: But when I change my PH to 7.6-7.8, the CSI goes up to -.15 to +.03
 

Frank in FL

Well-known member
Jul 3, 2019
326
Florida
Sorry, I left the "T" off (TFP). :)

Yeah, there's no reason to have the pH so low unless you are starting a SLAM. Let the pH rise to about 7.6 or so and you'll be in good shape.
In one of my other threads with high ALK, I was told to do a heavy dose of acid to bring the alk down. small doses dont have the same effect as one BIG one. I need to run my bubblers to aerate the pool and let the ph climb. Ive always let the ph get to 7.8-8.0 before I knocked it down to 7.4. But with these new numbers, I need to stay no lower than 7.6.