pH Drifts Upward

[Mike434]

Hello,
I sanitize my vinyl lined pool with liquid chlorine (12.5% sodium hypochlorite) and I try to keep the level of free chlorine at 7.5% of CYA. While I understand from this forum that increases in pH from liquid Cl should be offset by the decomposition process that hasn't been my experience. My pH regularly drifts above 8.0 and has to be brought back down, which I do with muriatic acid. I see that someone posted about a similar issue back in 2020. I'm wondering if anyone has any updated advice. My current levels are:
FC: 3.5 ppm
pH: 7.4
TA: 90 ppm
CYA: 40 ppm
Thanks in advance.

 

[JohnT]

Some water just tends to like higher pH. If you keep knocking your pH down close to 7, the TA will eventually go down and the pH should stabilize.

 

[Mike434]

Some water just tends to like higher pH. If you keep knocking your pH down close to 7, the TA will eventually go down and the pH should stabilize.

Thank you.