Welcome to our forum.
You'll see this elsewhere if you search, but it is important to get total alkalinity (TA) correct, and THEN correct PH. Otherwise, PH is prone to swing up / down "wildly". It is "normal" to require PH increaser periodically, as the dichlor (chlorine) will have a PH lower than the ideal range for your tub, and will cause it to drop over time. I add PH increaser weekly, also.
Remember your experience with your water may not be right for everyone else either!Vinny