Once you start to dose the Alk, your calcium is going to change, so make sure to watch for it. Also make sure you Mag is at the proper levels.
Attatched images below. I have them setup so that they will never rn at the same time, and if pH goes above 8.5, they will both shut off until it drops below that (which is rarely, but better safe than sorry).
Also, make sure to adjust the dosing time/s, DO NOT use the times I have, since every system is different.
Alkalinity is based from 75 minutes
Calcium is based from 60 minutes