What's more important - pH or CSI

[joelans]

I have a plaster pool with a SWG. Based on Pool Math, it recommends an ideal pH of between 7.6-7.8, and recommended range of 7.2-8.0. Right now, I have a pH of 7.8 and CSI of -0.13, both of which are good (I know for a SWG, want to keep the CSI between -0.3 and 0.0). To get that CSI of -0.13, my other numbers are: pH 7.8; TA 60 ppm; CH 375 ppm; CYA 75; Temp 85.

Now, if I want to get the CSI closer to 0, I would need to raise the pH to about 7.9, and that would get me to -0.04, or pH 8.0 which would get me to 0.06, but a pH of 7.9 or 8.0 is outside of the ideal range of 7.6-7.8. Likewise, if I bring the pH down to 7.6 (still within the ideal range), the CSI will be -0.31.

So, what's more important - the ideal pH range of 7.6-7.8, or keeping CSI between -0.3-0.0?

Thanks in advance.

 

[cwswifty]

Nothing wrong with a pH of 8.0 as long as your CSI is in the appropriate range. Like you, I target a CSI between -0.3 and 0.0. That usually has me adding MA to lower pH when it's up near 8.1.

 

[TinFoilHat]

Why mess with it at all? You're right in the sweet spot now so just keep it there. If your PH is happy between 7.8 and 8.0 then you're fine.

 

[ajw22]

Any pH in the 7s is equally ok.

Any CSI between-0.3 and +0.3 is equally ok.

You don’t need to micro manage your water chemistry.