as far as a filter goes, the live rock will be your "filter." i have a 12g nano with no skimmer as long as you don't have more than 2-3 small fish like firefish or small gobies or blennies you should be fine as long as you do a weekly water change, 2 gallons imo. lighting, power compact if you want to try your luck at some coral, you don't need t-5 or metal halide for a small tank like that. i would also try to get some sand that has been in someones tank for a while "live sand" and put that over the sand you put in, oh and i wouldn't use crused coral either. hope that helps. jake