I had a 12x12x12 7g set up on my desk at work for a couple years I had a par 38 marine light made by a guy on nano reef forum, and 2 little fishies reactor with matrix and puigen, and a skilter. I would deffinately get a skimming device the skilter was ok but not great. I eventually made a better one. I had a pink birds nest and a ponape birds nest and high end zoas, 1 cleaner shrimp and a purple fire fish. Weekly 1 gallon water changes were good with daily top offs of fresh water. The corals grew quite well and the fish and shrimp were happy.