I use API for ph, ammonia and nitrite. I have API for nitrates too and salifert. The other stuff I use salifert tets kits.
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.