No I do not top off with kalk. I have two 120 gallon reservoirs which one holds PH adjusted top off water, and the other one holds salt water.
Right now I have been using the Bubble Magus doser to put Mag back in the tank but was reading up on the Neomag just a week or so ago. I read that this is used at a rate of 1 part Neomag and 10 parts CA media. Is that close to what your doing?
I'm using the ARM right now, but only because that is what came with the reactor when I got it and wanted to give it a try. It's only been running a month or so, but I am getting good results, and my Alk which used to stay around 6 before is holding around 10.