Well, here's the deal with it. I had to leave on vacation for about ten days, and the fish only got fed by an automatic feeder. When I got back, the fish was looking normal again. Now that I've returned, occasionally give them a feeding in between their normal auto feeding, and the guy is starting to puff up again. So, I've stopped the in between feedings other than to throw in a few sinking things for the bottom feeders.