CSI question

[Thatgirl71]

It is an index for calcium saturation. Too high and you get scale. Too low and you damage plaster/grout. You want it near zero.

If you follow the levels we recommend, the CSI will stay in range. It is generally not something you need to worry about.

Using pool calc, my CSI is saying 0.6 now -0.23 target. What does this mean? And how was this determined? and how do I fix this?

pH 8.4 just added muriatic acid
FC 30
don't understand this one either recent slam but it was 18 last week, just turn down swg to 30%

CH 300
CYA 100
Salt 3300

 

[singingpond]

Re: CSI

Using pool calc, my CSI is saying 0.6 now -0.23 target. What does this mean? And how was this determined? and how do I fix this?

I'm not sure why you have that target number -- the target column is a number that you enter yourself (in other words, your target for that particular measurement). PoolMath then tells you what to do to reach the target you have chosen. What is your TA (total alkalinity) -- that doesn't seem to be included in your listed test results, and it has an effect on the calculated CSI level in PoolMath?

pH 8.4 just added muriatic acid
FC 30
don't understand this one either recent slam but it was 18 last week, just turn down swg to 30%

CH 300
CYA 100
Salt 3300

With regard to the muriatic acid addition, pH measures falsely high when FC is high (when FC is above 10, which yours certainly is). Thus, your actual pH is likely lower than 8.4, and you may have overshot your goal by adding acid based on that 8.4 measurement.

I'm sure others will address your questions about the SWG system; I know very little about those.

Also, it's generally best to start your own thread with your questions, rather than tacking onto someone else's thread about a related topic.

 

[Dreampool13]

Re: CSI

From what I understand, if your csi is too high (above .6), then you will get calcium deposits, and if it's too low (below -.6) your water will try to correct itself by leaching minerals out of your plaster and can cause pitting and rough areas on the surface of your pool. The fastest way to swing the number to an ideal level is to adjust your pH. I have a lot if calcium in my pool (about 500), and by fiddling with numbers on the pool calc, I can keep my CSI in a happy range by keeping my pH at 7.2.

"Funny" story...I was looking at my spa spillover and have been scratching my head at all the calcium being deposited on my stone. I had a lightbulb moment and decided to test my spa separately from my pool. PH was higher than 8.4...it was a deep purple but I couldn't tell you exactly how high it was. I assumed that since the spa spills into the pool, that the water would be the same as my pool. Nope, not the case! I lowered my spa to 7.2 a few days ago. All of the sudden, I'm not battling wide swings in my pH in my pool anymore. I guess when you stop a source of high pH water from pouring into your pool all day, the pool pH will stabilize and I won't need to add acid every other day. Imagine that. Anyway, Now that I've figured out my csi problem on my spa spillover, hopefully the calcium staining will stop. It only took me a year to figure that out.