I also dose kalkwasser in conjunction with Ca2+ reactor. I dump about 1 cup of kalk a week. The vat that feeds the kalk reactor, I dose vinegar, 2 shot glass a night. Hardly ever clean my unit, bc it sits in the sump. (420g display, 60gal sump)
For those that are using calcium reactor along with the kalk, I recommend that you keep the affluent to the calcium reactor as far as possible from where you are dripping kalkwasser. otherwise the kalk is going to elevate the pH of the water that feeds the calcium reactor, and that means you would have to feed extra CO2 to your reactor to lower the pH. As for me, I feed my affluent from the main display tank.