I tend to think of it like this;

total alkalinity is to ph as cya is to free chlorine.

So alkalinity is kind of a stabilizer to ph......

Would you agree??

BTW, I was somewhat suprised to see my start of the season cya level was already at 60......I kept it at about 35-40 last season, using just bleach and an occasional pack of shock, neither had cya......
But for over the winter, I did add a floater with 5 pucks in it in the fall, and 5 more pucks as soon as the ice melted, so 10 pucks raised it about 20.....

After I add the needed 10 or more inches of water to get the pool level up to the normal level, the cya should be down a bit more. I'll use mostly bleach this year, but boy, that too jumped up a bit in price.....oh well, life is still good......!

Frank D.