I'll have to agree with LiveRock27. Your tank's missing something. It's just so...empty. I'm thinking perhaps a nurse shark could fill the void. Or if you're feeling especially daring, you could throw in a nice freshwater fish...like, say, a Cichlid or two. I've always thought that freshwater and saltwater fish would get along just fine. I mean, after all, they're both fish except they just live in different kinds of water.
=D