I got an RBTA from a friend whose huge one split. I put it in the tank and set it roughly where I wanted it to be and it seemed to settle in. Over night though it moved about six inches over and around to the back side of the rock structure where I can barely see it. I tried to pull it off and move it, but the rock has so many nooks and crannies, there's no way to get under it and pry it off. It there any way to coax it to move around to the front?