I have a mixed nano. I tried going to just sps, but I am too in love with diversity and exotic colors. I have LPS, sps, zoos, shrooms, xenia, palys, and more. Wow, hard to believe they all fit.
I have not had luck with kalkwasser either. I also tried the Salifert All-in-One and trace hard. I had difficulty keeping the values stable despite otherwise good results.
I now use Oceans Blend 2 part and that did the trick. The beauty of this brand is that it also has all other trace elements so there is no need to purchase any other additives. It is also less expensive than other brands. I soley rely on Oceans Blend 2 part and weekly 20% water changes with RO/DI and Instant Ocean salt. I prefer to mix my own so I can control the SG.
I feed the corals once or twice a week with TLF Phytoplan and Cyclopeeze. I also feed the fish once to three times a week.
I have been meaning to suggest to you. I think you said your last test revealed 1.022 SG. This is good for fish, but too low for corals. Aim for 1.025 with +/- .001 tolerance. Corals will thrive better with near NSW levels of salinity.