Well, with the stock lighting of the DX, you can keep, mushrooms, zoanthids, palythoas, xenia and other low light corals. There are a couple of specialized
skimmers for nanos, but
IMO, none of them work very well, and you are far better off maintaining good water quality through regular water changes.
I wouldn't necessarily reccomend a nano as a first marine tank. The reduced water volume makes it harder to maintain good water quality, and things can go down hill really, reallt fast.
