So far I have, 3 clams, a clownfish, pipefish and LPS corals. I've a pink streaked wrasse in QT soon to go in too. The coral love fish waste, oh and I make sure tank husbandry is done.
My local LFS (Cuttle Fish & Corals - they are awesome!) said you can get away with having more fish if it includes firefish & other gobies in nano’s because they have a low bio load, not very active fish.