Does your pistol dig extensive burrows all over the tank like a jawfish. I just got a orange spotted goby and a candy cane pistol and he has built a burrow in the sand inside a rock. Do you think he could have excavated that rock out. I forget what it was shaped like when setting up the tank, but anyways, tank looks really good. I would probaly get some nassarius snails to mix up your sand bed and to have your pistol always working and building new tunnels/burrows.