I have an Update !! Since I have implemented the changes, the unmolted crab has gone under, and th injured crab is on the surface, and seems to hang out over in the corner. What I have notices is that he does not hide in his shell when I come near the tank, he just seems to go about his business. Does this mean that he is more happy and less stressed out? As for the "wood" I do have that stuff and will put it back inside the tank.