I don't post much ,but have been doing this for 20+ yrs. If you mean saturated lime water when you refer to kalk dosing here ifs my experience. I use "kalkwasser", i.e. saturated limewater for my top off water to offset evaporation. I also do this because I have humans and gas appliances in my house, by testing I know I have high CO2 levels. This allows me to boost my PH to around 7.9 to 8.1. I have learned to not try and force PH to desired levels to much. Your air conditions around the tank will effect the PH the most. BTW by using lime water as top off my Ca and ALK stay in balance. If I do need to boost ALK or Ca I then start a dosing regiment.