When adding new fish to a new system I generally test for ammonia, nitrites and nitrates as well. If you see a spike in the first two then you know you have some water changes to do. lol I usually test every day or every other for say a week or two just to be sure.
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.