I've never used Kalkwasser, although I have heard some good things about it. I've been trying to use ESV Bionic but I haven't quite figured it out completely. Currently, I'm seeing changes in alk without the same changes being present in Cal and Mg. I know I'm supposed to dose the 2 part equally, but the testing results to this point don't support doing that. While that has nothing to do with my Phosphate issue, it's part of my overall challenge right now with these tanks. I started dosing NoPoX again as a stop-gap measure until I figure out what to do next.