Calcium scale crystals

[mc2021]

The pool was just opened yesterday afternoon and I ran the first set of tests (tf-100) this morning after letting it circulate overnight. The PH was off the charts high, it took 2 gallons of 31% MA to get it down to 7.7 which means it was around 9.2. My Polaris is picking up a ton of crystal like stuff which fizzes nicely when I put some MA on it. From what I can tell, this is calcium scale. I had this last year too and I thought it was undissolved salt. My questions are:

1) Assuming I should just let the Polaris pick it up and keep everything else in line (slightly negative CSI) , nothing else to worry about?
2) Any way to prevent this from happening in future? PH rise is a constant struggle here and I'm hoping to get the TA down this summer but over winter, I can't do anything about it.

Thank you

 

[ajw22]

Run your CSI very negative -0.6 to -0.8 if you can for a few weeks and it should melt the scale.

Use PoolMath and enable sharing so we can review your water chemistry.

Are you tracking your CSI?

What was your water chemistry when you closed the pool?

 

[mc2021]

I just enabled sharing but I'm not real consistent on logging but there are some there. I try to keep the csi slightly negative and there is no build up on the swg. At closing I dropped the ph to 7.3 or 7.4 and brought cl up to slam around 35ppm.

I work on getting csi down for a few weeks. Thanks

 

[ajw22]

You may have to make more chemistry adjustments before closing then lowering your pH. I can't say until I see what all your numbers are.

Not having buildup on the SWG is irrelevant as that is not your winter water chemistry.

 

[mc2021]

Here's one from today and Oct which was about 3 weeks before closing. Nothing would have changed outside of ph and cl although the ta may have been closer to 70. Water Temps get into the 30s here and the top of the pool will freeze.

 

[ajw22]

Lower your TA to 50-60 before closing.

 

[mc2021]

The pool will be 2 in Aug and I've been fighting the ph rising even at the end of last year. I'm going to keep the csi very negative like you suggested by keeping the ph around 7.1 to 7.2 which will also lower my ta. Once I get the ta down, do you think adding borates will help my situation? I was thinking of researching them some more but was curious if you thought that would help or hinder things.

Thanks for the advice

 

[ajw22]

You can give borates a try.

Borates in pool - Further Reading

www.troublefreepool.com

 

[JoyfulNoise]

One thing you could try is adding scale inhibitor (like BeauTec) at closing. I would also avoid high FC levels on immediate closing. You can SLAM before closing but then let the pool stay open for an additional week until the chlorine levels drop down so you can measure pH accurately right at closing and adjust as needed. Adding a giant slug of chlorine and closing can cause the pH to spike up from the lye in the liquid chlorine which can lead to elevated pH for a long period of time. That in turn will exacerbate scaling.