I have a 16 and a 29 gallon set up with the following: Bio-wheel filters (as large as you can go to increase hourly water turn over), maxi-jet power heads with rotator attachment, heater, Aqua C Remora hang on skimmer and Dual Sattelite PC lighting. This allows to me to have all but the strong light corals in my tanks and IMO the skimmer is key to keeping water stable in a smaller tank. Pricey but worth it if you can add it at some point. I have sand for base that was seeded with a pound of live sand and lots of live rock. One tank has the fine sugar sand, the other a coarse variety. Thi sis a personaal preference and also can depend on what you would like to stock. :happyfish