I have decided based on dementions and goalos i will be going from a 12 to 20long. i currently have a spare 10 i will use as a sump/refug. my question is what else could i keep fish wise, i thought a nother fire fish to go along with the false perc and red fire fish i have now. maby a sand burrower of sorts or a really neat fish like an angel or something. any ideas?