Haha ok i forgot to mention that the rocks look conjested, but there are alot of space inside. The rock is made like this. Side view | water | water | ( | means rock). From the front u see all conjested, but when u look from the side, there are gaps in between. Like layers. Alternating between rock, water, rock water and finally rock. So from the front view it looks like the rockscape is too packed, but in actualy fact, its not. Haha regarding the overflow, never thought of that lor lols. I live the empty space there with the sand, for my fish to play and feed. There is a sand dollar that refuses to go anywhere but that area haha.