PH Concern

[MicheleS]

I have been using the BBB method for several weeks now and that, coupled with this site, have given me clear pool water for the first time in a long time. I have to remember to take a photo to post soon Anyway, I have high CYA levels (even after draining the pool to 80% twice) so my results are:

FC = 16
CC = 0
PH = 7.2
CH = 400
TA = 100
CYA = 90

I have read in several places on this board that if the FC level is high, then PH readings will be inaccurate. My PH level has held steady at 7.2 for over a week once I was done shocking with liquid chlorine and let the FC level fall to target based on my CYA.

Should I be concerned that my PH is testing at 7.2 with the FC level I have?

Thanks!
Michele

 

[Guest]

IF you are using a Taylor or TF100 testkit then your pH reading is going to be close to where it should be, just possibly reading slighly higher than the actual pH since the pH indicator in these test kits will give accurate results up to about 10 -15 ppm FC levels. Other test kits may not. High FC levels will cause the pH to read much higher than it actually is because of a chemical interference.
I would do another drain and refill to get the CYA down a bit more and then take it from there so you don't have to run high FC levels (and your FC of 16 is really higher than it needs to be for a CYA of 90 ppm , 8-10 pm should be just fine).

 

[MicheleS]

I'm using a TF100 test kit. The FC is still falling from when I shocked it so I should've have written that I was still letting the FC fall to target range. I live in SW Florida, so draining/re-filling a pool is expensive and I've done it twice this month already to about 80% refill both times. Not sure if I want the expensive of doing it again right now

I know I'll have to do it at some point though.

 

[duraleigh]

Hi, Michele,

The high CYA appears to be the only test result that is out of whack. Evan is the guru for testing methods so you can take his pH advice to the bank.......your pH is almost surely 7.2.

I understand about the expense of draining. Keep your FC up in the range Evan talked about. Never let it stay below that 8-10 range or you risk algae.

You may get some dilution that will lower your CYA over the winter. Not very likely, but maybe. You will have a much happier pool when your CYA is lower.

 

[MicheleS]

Thanks Dave. I am going to bite the bullet and do another partial drain/refill next week and hopefully get the CYA down. Other than that, my pool is looking great thanks to this site. :-D