I have to agree with Mike, you have to get to know your milk
For example, with one place I got my milk in 2018 a recepie worked with 2 day old skim milk at 3 tsp CA (Citric Acid)
Wheras I followed the same recepie, with same 2 days old skim milk from another place in 2020, in spring rather than fall, and I had to cut it down to 2 tsp CA.
The next time I knew to add less, and went slowing increasing until perfect for this milk, season, etc. Ph meter helps cut down on frustration, but if doing every day/week with same circumstances you will get a feel for it.
Several times Ive saved a batch that went too acidic by modifying the stretch water to compensate and wound up with perfect ph mozz....
Keep at it, it will come (says the person who tried and failed for 16 weeks in a row until she got it
)