I was thinking of filling the whole top section with rock wall, plants, tree limbs, and whatever else. I believe the top section is 4x5x161/2. thats 2 more feet than he has now in height and 3 1/2 feet more in width. i would rather it be 2' deep but it is only $50 and i think its a pretty good start. I see alot of people that have they're babies/juvies in a much smaller cage i.e. 55-90 gallon. I'll keep looking for better but worst case I can make this work I think.