Depends on a few factors, such as if the rock was cured completely and how long it was out of water on its way to your tank. You can easily test to check by dosing the tank to about 2ppm of ammonia....if its gone within 24 hours you are cycled. If not then you need to cycle.
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.