I fully saturate kalk (residue on bottom of vat), drip to evap rate. For me it's about 1 drop every 2 sec on a 92 corner w/ sump. That works out to about a gal a day. You can prob go much higher than a drop every 20 sec.
I prob kalk every other week, in between it's RODI via ATO. I won't claim that I keep up with my testing, maybe once every couple of weeks, this system works for me and keeps alk/ph/ca right in the ideal range. Moderate calcium demand in my tank BTW.
Hope this helps.