Need CSI advice


Silver Supporter
Jul 21, 2015
Cape May Court House, NJ
Opened the pool yesterday and the water is a beautiful TFP clear – yay! :kim:But my CSI is a bit low and I'm not sure what to do about it.

Here are the readings:

FC: 5
CC: 0.5
pH: 7.3
CH: 225
TA: 60
Salt: 2800
CYA: 70
CSI: -.99

Any suggestions for adjustments?


TFP Expert
Feb 3, 2014
Central Minnesota
I'd let things live for a few days to see what happens with the pH. It may rise on it's own over the next several days. If you want to help it rise, you could introduce some aeration by aiming your returns upwards toward the pool surface, creating as much ripples/turbulence as you can. If that does not work, consider adding some borax to raise pH to about 7.6 to 7.8. Use small additions to approach the pH slowly.

Also... in a fiberglass pool, like vinyl, CSI is not overly critical so don't fret too much about it.


Mod Squad
TFP Expert
Platinum Supporter
LifeTime Supporter
In The Industry
Apr 1, 2007
Sebring, Florida
Don't touch a thing. Your numbers are just about dead on perfect.

I am not a big fan for this very reason. Your pool is fine and chasing CSI with your fibreglass pool and your NJ location is simply not relevant.
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