very lethargic betta boy

Question
I've had my betta for close to a year.  The day after getting a new male (separate but adjoining bowls), my older betta stopped swimming.  He stays at the bottom of the bowl and won't surface for food.  He will occasionally come to the top for a gasp of air.  At the bottom, he will sometimes rest in his plant, but he mostly leans against the side.  When he is well, he is very particular and will eat only freeze dried bloodworms.  I think I may have given too much food which he consumed maybe more aggressively than usual because of the new fish's presence.  I've had goldfish with SBD and have had only one recover for a short time despite my best efforts.  I think this may be what is troubling him.  He will not eat peas nor algae tabs.  I tried the antibiotics that I've used with goldfish, but did not see any improvement.  He does not seem to have any other symptoms.  He has been this way for over three weeks.  I am going to try the Epsom salt treatment.  Any other ideas would be greatly appreciated.  Thank you.

Answer
Laura,

The Epsom salt bath is a good idea. You didn't mention a heater. What do you have's set too. Betta's are tropical fish and need warm water. Also, the Betta bowls are way too small. All 10 of my adults are in 2.5 gallon tanks and that would be the smallest I would put them in. You can also add a little bit of aquarium salt to his tank water. Let me know how the bath goes.