I have had my beta Fitzy about 6 months and he has been doing great until a few days ago. A couple of days ago he started acting letharthic and hanging around the top corner of the tank. I changed his water tonight and he immediately went to the bottom of the tank and was struggling to swim, plus he was tilting on his side. Now a couple of hours later he seems to be doing a little better is swimming around a little more and still tilting sideways a little. Any ideas? He is in a 2.5 gal. tank, his water temp. is about 72 I feed him pellets and I do full water change every other week and a half change inbetween.