I had a 10g nano set up for about 2 1/2 years, and to date, it has been one of my most satisfying tanks, however you do have to stay right on top of it. I changed a gallon of water every other day, which when you think about it, is pretty easy maint. compared to some of my other tanks...
I used a retro kit for the light sold on
www.ahsupply.com. The fish were kept to a min. Just two percula clowns, and a watchman gobie along with a couple cleaner shrimp, and some hermits. About 15lbs of LR and a bunch of mushrooms and button poylops. I tried to avoid sensative corals do the size of the tank, one little slip, and they would of suffered greatly. At any rate, the point I'm getting at is a nano can be done, and work very well, but there are limitations. As for the picture you saw on the box.....well, lets just say I'd like to smack the person responsible...
Side note(in case you were wondering) I no longer have my nano because after 2 1/2 years, one day I awoke to a carpet of green hair algea in the tank, and after battaling it for about 3 months, I threw in the towel, and figured the residents were better off moving out.
"J"