the question is: Are you comfortable with your set up? If you have enough surface to hold enough bacteria, enough mechanical to keep the water clear, and the ability to spot treat any transitory conditions, I would say you have enough filtration. if you develop filter feeders then your biological filtration will have another dimension. I am 9 months into my first SW tank, and 4 months into my second. They both have skimmers, rock, and sand. I have a piece of floss in the big one, temporarily, no socks in either. I am seeing a lot of wild organisms in them.
There are no fish in the first since i moved them to the second. Good luck, and let it rip! lol