I've been planning this for ages and finally decided to do it. There is a large walk in cupboard sort of affair in my sons room. He is in the forces and doesn't live at home, so it seemed fair game. I got a joiner friend to knock me up a base unit. Its 6ft long almost exactly, which will prove to be lucky or unlucky soon. The worktops are 2 ft deep. I'm planning 6 24*12*15 tanks end on up top, and I have a 36*12*15 and 30*12*15 to go on the bottom. THe 24" tanks are on order and should arrive this week, then I'll see if 6 will fit in. It will be tight but hopefully my measurements are good.