What have you done to your back wall?

[Mr. Microscope]

I say unless you're going to do up the whole back wall with rubble to look like a drop off or something, leave it blank. IMO, a tank starts to look cluttered when corals are mounted to the back wall. Most branching SPS only encrust in a circular patter and it looks distracting. Leaving the back wall black makes your overall aquascape pop more.

I do really like that shadowbox thing though...