PH drifts up

[berger]

6,000 gal above ground pool
FC=5
CC=0
PH=Drifted up to 8 in 2 days after adjusting to 7.5
TA=110
CH=160
SI=2.5 because of high PH
CYA=40
Having trouble keeping PH down.

 

[pooldv]

Your PH is drifting up because the TA is high. Continuing to add acid to lower PH will slowly lower TA. Eventually, TA and PH will reach equilibrium. Or you can lower TA following this process, Pool School - Lower Total Alkalinity. Lower TA to 80 and see if PH stops rising. Then 70 and then 60.