Difficulty following recommended levels AND staying within CSI range.

[Bradleyebyrd]

Hi guys, long time reader, first time poster.

I have a difficult time with finding the perfect chemistry for my pool while keeping the CSI level between -.3 and .3. My pool always is on the low end of CSI even if my levels are within the recommended range.

Today I had the following measurements:
PH 7.4
TA 80
CH 350
CYA 70
Temp 82
Salt 3300
Borates 40
CSI -0.41

The only reasonable way I am able to get the CSI within reasonable levels is to either reduce the PH range to 7.6-7.8, Raise the CH to 550, or go outside the recommended levels of TA. The water temp could be raised but that's not a sustainable solution.

Out of the options above, which one would be least harmful? Increasing CH would be the easiest long term solution in a beginners eyes (myself), but what am I missing?

 

[Texas Splash]

Welcome! I haven't checked poolmath, but if your numbers above are correct, why not just let the pH rise up a bit? Just a short increase to about 7.6-7.7 and you should be fine.

 

[Jimrahbe]

Brad,

Most saltwater pools like their pH to be 7.8 or so... Why not let it just sit there?

I used your numbers and letting your pH sit at 7.8 makes your CSI -.07



Thanks,

Jim R.

 

[Bradleyebyrd]

I didn't realize that saltwater pools like to be at 7.8. Again I was going off of the recommended levels in Pool School for a saltwater plaster pool. Those recommendations don't really seem to work for CSI unless PH is kept on the high end.

 

[mknauss]

The recommended levels show pH of 7.2-7.8. So, a pH of 7.8 is within the recommended levels.