How important is CSI?

[mmardini]

Hey everyone,
I just upgraded my pool math app so I can finally log my results, and my csi is a little too low (-0.77).

a little background, I had the pool resurfaced and filled on October 5th of this year. I test using the Taylor k2006 test kit. I live in Palm Springs California and we have hard water here. We used all glass tile when we remodeled the pool (waterline and spa face), and one of our main goals is to avoid as much calcium deposits on the tile as possible. Our previous tile had a lot of calcium scaling on them that was impossible to get off. Here are my results from today (not sure how to share pool math stats yet, I’ll figure it out!)

FC: 3
CC: 0
PH: 7.2
CYA: 30
TA: 70
CH: 270
Temp: 54 degrees.

I know the pH is on the low side, but won’t that help control the scaling? Calcium is low too but I know it will come up eventually with our water source. So with these numbers, should I worry about csi? I played with the numbers a bit and it looks like if I raise pH and CH I can get my CSI to a more acceptable range, but I’m worried about doing that.
Thanks for your help!

 

[mknauss]

Your calcium and TA are fine. Let the pH rise. Should be little scaling during colder water temperatures.

 

[mknauss]

The last time you added acid was 25 days ago and your pH is still 7.2?
Also, your pool volume is more than 1500 gallons, right? That is what is showing in Poolmath.

 

[mmardini]

The last time you added acid was 25 days ago and your pH is still 7.2?
Also, your pool volume is more than 1500 gallons, right? That is what is showing in Poolmath.

No that’s not correct I haven’t updated it. I wasn’t really using the app until yesterday when I upgraded to the paid subscription. I last added acid this past Wednesday. I believe the pool is about 15,000 gallons (15x30x4.5 average depth).

 

[mmardini]

The last time you added acid was 25 days ago and your pH is still 7.2?
Also, your pool volume is more than 1500 gallons, right? That is what is showing in Poolmath.

I must have done a typo for the 1500 gallons. Should be 15,000. I’ll update that now

 

[mmardini]

The last time you added acid was 25 days ago and your pH is still 7.2?
Also, your pool volume is more than 1500 gallons, right? That is what is showing in Poolmath.

also, disregard the test results from yesterday, I didn’t actually test yesterday I was just testing out the app based on previous measurements. Today’s are accurate

 

[Leebo]

How important is CSI? It’s anywhere from a worthless number to a vital piece of info for your pool......one of those two.

CSI as a number can be set aside for many pool owners. Users can often skip paying attention to this number as long as they can easily maintain TFP’s Recommended Levels on a daily basis. For now at least, you appear to fall into this category. Your CH level doesn’t seem to be sky high nor is your TA. Depending on your fill water this trend may continue where your numbers stay low, and that’s a win for you!

That said, you may also find your CH level steadily increasing in the future. You may find your CH level creaking into a high risk area where you’ll start to see scale. In this case CSI becomes vital. Because you can’t easily control calcium you’ll start to use CSI to control scale by juggling other variables you can control, mainly pH and TA. You’ll use CSI to balance the high CH level my maintaining a lower pH level.

For now as you learn it appears you can somewhat set CSI aside as your numbers appear to be very good. As Marty said, let your pH increase slightly and your life will come easier.

 

[mmardini]

Thank you both so much! Both of your answers really helped! I was keeping pH low to avoid scaling but ill
Let it rise a bit and see what happens over the next few months as our temps increase.