I'm a newbie but from what I've read the main benefit of Kalkwasser is that it replenishes calcium in the reef tank while maintaining alk!?!?! That is what this is for. The Dow Flake is for calcium, the baking soda is the Alk counterpart, and the Mag Flake/Epsom salt is for the mag supplement. Cheaper but it is 3 separate parts you are dosing, where the Kalk is just one?!?!?!
So this like B-ionic, but cheaper and better to me. At elast based on the research I have read that Randy has done. I guess you could still use kalk if you can not maintain the calcium/alk levels w/ the 2-part. Might be redundant though. Also since you are using kalk, i am guess that your PH is naturally low? if so you'd want to do his recipe #1.
Cause I'm a noob though, I'd post in the Reef Chemistry Forum on the main forum page. Randy will tell you, cause I could be wrong.