Miserable Betta

Question
I changed the 1-gallon tank yesterday the same way I always do - used same temp water, cleaned the rocks, etc. I've had him for more than a year, I don't know how old he was when I got him. Today, he's just miserable. Floats vertically sometimes, tonight he was lying on his side on the rocks, when he awakens, he makes a mad dash for the surface (the tank is uncovered), pokes his nose out with a bubble or two, then floats back to the bottom. He's very, very lethargic - normally he likes to play "follow the finger" around the tanks. No interest at all now. It seems there is a little discoloration, he's not as vibrantly red as he normally is. My house temp is usually between 63-68 degrees, and it has been for the past year - as long as I've had him. Perhaps thats too cold (from reading other posts), but I'm not sure why it would suddenly affect him now. We are trying to warm him with a small lamp right now to see if that has any effect. Any other ideas?
Thanks for your time/help...

Answer
Hi Andy,
  When you change water, you shouldn't change more than 50% at a time or else you may shock your fish by the change in water chemistry.  Perhaps this is what has happened in this case.

 The temp you mention 63-68 is pretty chilly for a tropical fish like a betta.  He would be much happier up in the mid 70's.

-- Ron
  rcoleman@cichlidresearch.com
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