Yeah, it's not bad with a 75g, but I couldn't imagine double 90s or 120s on this stand (if 120g 4ft tanks really exist). So tall you'd need a ladder and you'd have no room above the lower tank.
Duckie, the ~6" rear shelf behind the 55g on the bottom isn't enough room for the C-360 canister. I will be nice for air pumps and misc. stuff though. I'm planning on going with a piece of black plastic bag for the background. I may make up something for that gap between the tanks too. Good call there.
