I use I/O reef for my coral tanks and regular I/O for my fish only setups. I've tried red sea but found it didnt mix as well as I/O. Also have used Kent and Coralife briefly but always seem to come back to Instant Ocean. lol Generally cheap and works fine by me.
180g Reef - 60g Rimless Reef -90G FOWLR- 125g Malawi Cichlids- 40b REEF- 34g Fresh Planted-working on- 20L FOWLR- working on
I have a mix of many different saltwater fish amongst my tanks, but I love my Tangs most of all.