Stitch, i am in the same boat as you, looking for something different/unusual for a roughly 18x18x24 area that is walled off from the rest of my reef tank. It used to house my mantis, but unfortunately she died during her last molt. I loved having her, but without the ability to keep any kind of clean up crew in there I had a hard time keeping the algae under control so I was thinking of trying something different. I was thinking maybe a pair of pipefish or something?