I really like the aesthetics and footprint of cube aquariums, and I am really thinking of doing a largish cube as my next tank. I have some questions and concerns though. Keep in mind I am speaking about a cube of at least 100 gallons that has sides of 30 inches. How do fish who need large tanks for swimming room (tangs etc) do in cubes? How difficult/feasible is it to have the overflow in the middle of the tank with live rock covering it? What are some specific challenges with larger cubes that I should be aware of.