Hi. I'm new to the group. Having big problem with my common pleco. I've had him for close to a year and he's about 5 ,inches long. He's in a 20 gallon long with a Cory and 4 Betta Foerschi. All was well until about a week ago when he quit eating and started laying on back and side. Mouth seems to be open wider than usual. He's still breathing and moves around a little but mostly lays on back. I've done 2 partial water changes but it doesn't seemed to have helped. His tank mates are all OK. I would really hate to lose him. The only other odd behavior was he kept his tail bent about 45, degree angle when he was healthy and it didn't seem to interfere with swimming. Anyone have any ideas?