I think most people would agree you need some sort of clean up crew (CUC). In the 210 reef, we only have snails and in the 140 FOWLR we only have hermits. We used to mix them in the 210, but the hermits will kill the snails for their shells. It is frustrating to see a hermit kill a snail, try on its shell and then decide its old shell was better. The fish in the 140 eat the CUC, so I buy hermits every so often. They clean until they get eaten. Most hide and only come out at night.

As far as other stuff, we have some starfish, urchins, cucumbers, and a diamond goby (helps keep the sand clean). Then the other fish you stock can help also... We have a kole tang in the 140 (bristletooth tang) that helps with algae. Other tangs often help also, as do most rabbit fish and some blennys.