I have a 29G tank with 10G 'fuge (about 8 months old). Currently, besides some corals, I have 3 small blue green chromis and 2 cleaner shrimps. I would like to add another fish which would be active in the water column, swim in and around the rocks and would eat algae. For a bigger tank, something like a tang or foxface would be great but these don't work in a 29G. I've thought about a dwarf angel (a flame angel or pygmy/cherub angel would be really nice but I worry about the risk of it becoming a coral eater). Blennies would be interesting but aren't active like I want. I've run out of suggestions.

Anyone have any other thoughts?