83 today, have had tons of rain.
which is a whole-pool aerating event. No wonder your pH went up so quickly in a day.
For what it's worth, I'm dropping 20oz MA per day into my 70-80ppm TA pool. 16oz every third day isn't so terrible, I was used to doing 60 - 80 oz and playing the yo-yo game trying to get my TA down.
CYA only buffers your pH from dropping - not rising so I'm thinking this has no effect on my pH issue.
I don't think this is correct? Maybe a typo? CYA primarily helps keep your FC from falling and adding it will slightly drop pH.