pH just shot up

[clmsntiger1]

I've got a situation that I can't figure out. This is my first summer with a pool and using the TFPC method. So far I've been able to keep my pH consistent for the last couple months with little maintenance. It always slowing drops and I add borax from time to time to raise it, it's never gone high until now. I tested yesterday and today and my pH was 8.2, before that it was always around 7.6. I do not have any aerators on/in the pool. We've had an excess of rain the last couple days but I thought that was supposed to lower the pH. What could have caused it to rise so quickly?

Current results taken this morning
FC - 11 (raised it to clean my solar cover)
CC - 0
pH - 8.2
TA - 90
CYA - 60
CH -100

 

[Conjomen]

NOT AN EXPERT!
Ph tests are unreliable at higher chlorine levels. Basically anything above 10 FC. I'd wait until the FC levels are below 10ppm and restest the PH.

 

[JamieP]

Aside from the inaccuracy of testing PH with a high FC, rain causes lots of aeration so can raise PH too.

 

[clmsntiger1]

Thanks for the responses! I'm gonna head to Lowes and pick up some
muriatic acid because I don't have any on hand. I'll wait to add it until my FC drops further to be more accurate.

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[pookiesunshine]

Hello fellow Tiger! Yes, I would wait for chlorine to drop and retest pH before doing anything about it.