Well this thread really took off lol. I think what I am going to do is pull the rock out and just dump it. Im setting up a new tank now. As far as the conch theory, I do have one conch in there and the hole matches the size of his mouth. I really like him though so I hope thats not it. I will put the rock into a bucket of water and see if something is still in there. What sucks is its one of the big pieces of base rock at the bottom of the heap.