In general, the Kalk / Calc Combo Method involves maintaining proper water parameters by maximizing the addition of kalkwasser to the tank and supplementing with a calcium reactor if needed. This provides the benefits of kalkwasser including reducing phosphates, and raising pH, but also results in having to dose magnesium. The most important benefits are that once you get it set up and running, adjusting your water parameters is as simple as turning a knob, and maintenance is reduced to almost nothing.
The following article describing the Kalk / Calc Combo Method assumes you are running a sump in your aquarium system and that your alkalinity/calcium demand is so high that you cannot meet that demand with kalkwasser alone. If you are starting a new tank or otherwise do not have a high demand for alkalinity and calcium, I recommend that you only implement the kalkwassser part of this method and as your demand grows, add the calcium reactor part.
I recommend you read the entire article below before getting started on the setup. If you have any questions, feel free to send me a message at Reef Central my user ID is bbyat