I'll try getting a side pic tomorrow. He isn't very skittish and hand feeds when he's hungry. He all of sudden got it when he started eating tiny 3mm pellets. He sometimes has to bend his back backwards to get them down, and I suspect he does that too much which caused it?? I'm pretty sure he didn't hit the wall very hard. The walls are heavily covered by algae on three sides so that probably stops him or makes him feel more secure I think. What do you suggest I do if it was indeed him hitting the wall too hard?