I love my biocube!
I have a Citron Goby, 2 b&w clowns, a yellow watchman goby, a mandarina dn a scooter. Most of my fish stay on the sand bed or perched in the rocks so I;m not too terribly overstocked. lol
If you like check out this site for a filter mod for your cube:
BioCube 29 - Aquarium Filtration Upgrades & Supplies
180g Reef - 60g Rimless Reef -90G FOWLR- 125g Malawi Cichlids- 40b REEF- 34g Fresh Planted-working on- 20L FOWLR- working on
I have a mix of many different saltwater fish amongst my tanks, but I love my Tangs most of all.