What kind of test kit are you using to test? Liquid or strips? The presence of coralline means nothing as far as your cycle goes. I had bright pink coralline while I just began a cycle once.
I too would think with 2 fish in such a small tank that you should see some ammonia. Though with 2 fish in the tank you will be doing a water change as soon as you see ammonia to keep the fish alive. Are you reading 0 nitrates as well? After a cycle you will have some nitrates from the initial conversion of ammonia to nitrites to the trates.
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.