Thanks for the info guys. I'm not discounting the fact it may be one of the fish. But I'm leaning towards the water chemistry in my tank. He was fine until I added C-Balance 2 part solution. Since than, I've done water changes and monitored my KH more closely. The brain is recovering from what I can see. I have a plastic container over him with multiple holes for flow and protection. I no longer can see his skeleton, and he's getting coloration back into areas that has faded away. Thing is..He still will not release those feeding tentacles, either day or night.