Yeah I am. I'm taking a lot of the rock out of my 210 when I switch over to my 400 and I want to keep the rock in the system. I have a 120 that I will be using below it as my sump, and I want to put most of the rock in the 150. I have a steel stand for two 4' x 2' tanks, so I this will work out great. I'm building the 400 in to the wall and it's only 66" wide, and this will go directly behind the big tank in the fish room. And I can use the current holes drilled in the tank for a basic overflow.