About a week before this picture was taken the rocks were vacuumed and completely stired up while cleaning. Here you see how the Clowns have been moving the black rocks towards their caves.
I've left the front of the tank alone when cleaning and just over one month later you can see that they have made significant progress in moving the black rocks to the cave.
On the other side of the tank you can this smaller cave is completely filled with black rocks.
