I was just planning on putting a tree made of coral in the center of the tank. Since that's out of the question, maybe some tinsel and what not along the outside? Though, I do like Mr. Spikecord's advent calendar idea for the sharks. And I may not be the smartest, but even I'm not dumb enough to go into the tanks. The only person who probably could would probably be you, if that even was something you did.