the fish started with pop eye (i think for about 2 wks). I put him in a hospital tank and treated him w/maracyn for 2 wks...no help. When I put him back in the tank he was ok for a day or so, then he couldn't swim to the bottom of the tank. Almost like he has an airbubble in him that won't let him sink. He hasn't eaten since he got pop eye. Water quality is good, and I've had the fish for over a year