What else can I add to my aquarium?

Okay. I want your opinion. I have a 30 Gallon (tall) fish tank (freshwater). I have 4 Serpae Tetra, 2 Black Phantom Tetra, 2 Red Platies, 2 Mollies, and 3 Albino Corys. I also have one air stone and a 23" bubble wall. It is semi-densly planted and has one good size roman column ornament and one smaller size statue. You think I can do more? (If so, what?) Or is it good like it is?