Oceanic salt and RO/DI water for my Nano and the same plus a Geo calcium reactor for my 100G mixed reef. I also run a half dose of GFO and small amount of GAC in separate Phosban reactors and have chaetomorpha macroalgae in my refugium. Thats it, no other supplements or additives unless I find my magnesium level is low where I use BRS bulk two part magnesium mix.
Baking soda for alk, Calcium Chloride from BRS for Ca. WC's keep my Mg where it should be. I also dose kalk in my top off, which aids the Alk and Ca, and utilizes some of the CO2 in the system to help keep the pH up.