UPDATE: Sushi is still alive and kickin. I leave the filter off so I think I'm just going to take it off. Weekly 50% water changes seem to do the job. He's eating pellets and I feed them to him one at a time.. maybe 6 or seven pellets like 2x's a day. He swims to the front of the tank and just stares at me when I walk by. I think he just wants food all the time.