I started with IO Reef Crystals, then did a WC with some free stuff I got, and now I use Brightwell Neomarine blah blah (name is too long). Mix it with RO/DI water. Mixes up way faster than Reef Crystals, but leaves a residue in the bucket. All I really know is what I can tell from my corals and fish though. They all seem to be happy and growing and I have to dose Alk and Calc which I'm terrible at remembering to do. Though I think the biggest user of calc is the enormous amounts of coralline algae growing everywhere.