ChillDawg beat me to it, but I was thinking shellies, too. Throw in some crushed coral sand, some escargot shells from your local fine food store, and get yourself 4 Neolamprologus multifasciatus. Same cool family behaviors of the brichardi, but in my old 20 high I actually had a pair leave the parents area and start a rival group on the other side of the tank.
Plus, the fry will work as food for your other cichlids (not trying to be cruel, but multis like brichardis would overpopulate the earth if you don't periodically sell or cull the fry (actually, I got over $50 credit for my multis when I sold a large batch of fry (about 20 of them).
If you've never had multis, think brichardi at only 1.5 inches that hide in shells and dig about 2000 times more often than any other fish alive. They'll make sand walls about 8 to 10 inches high. Just level the sand when cleaning the tank and see how pissed off a dwarf cichlid can be! Seriously, they're a blast for little fish.
