Why has my pH been high this year?

[impulse22281]

Hi everyone, haven't posted much mainly because my pool has been trouble free. This isn't really a problem, just more of a question. My pH has been on the higher side all season. It's been 7.8 pretty much on the regular, but today it's up about 8.0. I'm not having any problems with my water, it's just weird. Last year my pH was always on the lower side and I was constantly adding Borax. This year is the total opposite yet nothing has changed. Last year my TA was consistently around 100, this year is 110 which is still normal range from what I can find on here. Just wondering what would cause this higher pH. Is it just the outdoor elements/air/trees/humidity etc? Should I add some MA to lower it? I figured 7.8 is normal so I haven't bothered, but 8.0 is a little high. We're suppose to get a lot of rain tonight/tomorrow (up to 2 inches) so it may just go down on it's own...I think? Anyway, just thought it was strange and was curious.

FC: 5.0
CC: 0.0
pH: 8.0
TA: 110
CYA: 40

 

[roc1479]

You can add MA to lower the alkalinity, but this will also bring your PH down. You can then aerate to bring up the PH, which shouldn't have much effect on TA.

Rain should cause PH to rise a bit because it creates aeration.

 

[Patrick_B]

I can't say for sure unless your fill water source increased, or your fill water supply changed. Your results don't reflect that really, but if you will target a low pH for a while (as in 7.2) your TA will work it's way down and you'll see a slower pH rise as it approaches and remains in the 60 PPM range.