TA climbing

[Kathyonthefarm]

Hello,
My TA keeps climbing............rained 2 days ago, a lot, TA was 150 after the rains(140 before),
NOW
TA 160
PH 7.3 ( down from yesterday of 7.4)
FC 6 (will be shocking because there is still green )
CYA 50
Cal 200

Inground, vinyl, 34k, sand filter, FULL sun
Thanks

 

[chem geek]

Other than test variation error, there's no good explanation I have for that. If there was evaporation and refill with water that had TA (which most water does), then that will lead to a slow rise in TA over time -- that's what happens in my own pool with fill water that has around 80 ppm TA. Normally rain will help aerate the water and will cause the pH to rise with no significant change in TA (a slight drop from dilution, but probably not measurable). Adding acid, of course, lowers both pH and TA.

Richard