Im not exactly sure.Following. I too am waiting on a 180g tank from Crystal Dynamics. I like your rock work. How many pounds of rock did you use?
We had/have a big 100G stock tub in the garage, that we cleaned all of our previous tanks rock in and then just used that. Never bothered to actually weigh it......
I think we are also going to have a marinepure block or something similar in the sump to add extra surface area for the bacteria to grow on since we are going on the lighter side of rock in the tank itself.
We wanted to keep the main display somewhat open so that the fish have room to swim and the corals have room to grow.