I guess to me a reef tank is more based on whats on the rock in terms of coral. My goal is always to cover up the rock with as much of it as possible, to me that's what defines a successful reef tank. I don't believe that extra diversity serves any purpose except to give newbs something to take a picture of and post asking what it is
My first two salt tanks had zero "live rock" and they did just fine. To say live rock is required or essential is just false information.
