The best way to add calcium

[Dorkel Marine 1]

I was contemplating dosing my tank after I get my new skimmer up and running. I've read the two best ways are to use kalk or a 2 part system. B-ionic and C- balance recommended. When you guys say to replace evaporated water with Kalk could you elaborate. I have two 27 gal tanks. I hope to interconnect the 2 in the future. The reason I'm leaning on the 2 part system is the reading I did says that with smaller tanks it is affordable. Its seems to me it would be easier than rigging up a system to drip the kalk. If adding the Kalk is not to complicated I would go with that, because it seems cheaper. Your views and recommendations would be appreciated. When I say dose I mean I want to start keeping the calcium level where they should be. I haven't ever done this yet. My tank profile is not up to date I haven't been able to figure out the new stuff on the board. Not to bright when it comes to finding my way around the board.
Thanx in advance George M.