Adjusted TA = TA – (CYA X CYA C.F) – (Borate x Borate CF)
Borate C.F (correction factor) based on pH.
pH.......CF
7.2.....0.051
7.4.......0.0786
7.6......0.1248
7.8......0.1989
Cyanuric Acid correction factor based on pH.
pH........CF
7.0.......0.22
7.1.......0.24
7.2.......0.26
7.3.......0.28
7.4.......0.30
7.5.......0.32
7.6.......0.33
7.7.......0.34
7.8.......0.35
7.9.......0.36
For example, if the pH = 7.6, TA = 90, Borate = 50 and CYA = 70, the adjusted alkalinity is 90 - (70 x 0.33) – (50 x 0.1248) = 60.66.
The CSI is what matters and the individual components are not as important.
Keep the pH between 7.2 and 7.9.
Keep the TA wherever it keeps the pH stable at the pH you want.
Keep the CSI between -0.3 and 0.0.
I recommend keeping the pH at about 7.8 and adjusting the other numbers from there.
Find the TA balance point by starting at about 60 ppm total or at least 40 ppm adjusted.
If the pH is stable, then, you're good.