At my old shop I had a 30 gallon with a bac-pac skimmer and few power heads, No other filtration. I had as much live rock as would fit and still look good and about 3" live sand bed. It had a lousy dual 30 watt strip light with a 50/50 & a actinic. It was absolutely packed with Zoa / palythoa polyps & mushrooms, xenia / anthellia, a trachyphyllia brain, galaxea, and a bunch of other stuff I can't remember. I had a pygmy (argi) angel, six line wrasse and a pair of percula in it. I did a gallon or two water change per week and dosed with calkwasser, calcium, iodine, strontium, magnesium & iron. I loved that tank. It was the cheapest POS set up I had in the shop and may have been one of the coolest.
Joel