Here is one for you....What in your mind is considered a Nano-Reef? I am kinda curious about what everyone else thinks about this subject. I have seen it hotly debated on other forums before...hopefully no one will get to sensitive about it here though.

Guess I will be the first target on this topic...

To my way of thinking, I would be inclined to consider anything that is 20 gallons of less to be a Nano-Reef. Why 20 gallons and under?

-Well for one these are pretty small tanks. Especially once you get 1 lbs per a gallon or more rock in them and a couple of inches of sand. Tanks this small fill up fast!
-Filtration systems are vastly different. On a larger Tanks usually a of some style or another become the prefered choice of filtration. On a Nano due to its size not only are HOB filters an option but they seem to be quiet popular. Hagens Aqua-Clear series are possibly the most popular in this application. They have also proven quiet versitile in that many hobbyist have converted some into HOB refugium with some minor mods.
-Adding other equipment such as skimmers normally takes up so much room that its not really feasable to use them.
-In a tank this small your limited to just a couple of small fish prehaps three at the most in more cases than not.