I've been having an algae issue lately. I was keeping the lights off in hopes to kill the algae off. I wasn't really rearranging, just flipping the driftwood and other rocks and such. Kept his lights on for a few hours in the AM, and a few at night. I think that's what caused him to flip out. He was in a 90 alone Cinamonster. I really don't think tank size matters though or was an issue as most tanks are pretty much the same depth. I think if he had more space he would've sealed his fate much faster.