I don't know how their system works.I'm looking at using the reef factory kh pro coupled with the hydros 10 for my security. The hydros ph meter will be controlling power to the dose pump just incase the dose pump until the ph rises again. Otherwise I'll do the same but with the kalkwasser and let the kh pro monitor the calcium reactor dosing.
What I like about the apex is that when it takes a reading it will dose either a percentage less or more which is user defined depending on the reading.
Example, if you have it set to 9.5 and it gets a reading of 9.6 you can have it set to dose 35% less until the next reading.
Here's a picture of the dosing schedule. The hour breaks are aware. The apex takes a reading and my kalkwasser stirrer stirs.