Swollen side

Question
I have a male betta whom I keep in a half gallon tank that is unheated now because it's summer. He's about a year old. We feed him a diet of a few live blood worms a day. Recently his left side has become swollen  at the gill and his fins have become ragged. I tried changing him and adding salt, but I'm at a lose as to what's wrong and how to fix it.

Answer
Hi Jessica,

Bettas are omnivores - they need both meat and plant material in their diet. While bloodworms are a great protein source, I recommend maybe only feeding them every few days as they are not good overall nutrition. It is like feeding a child chocolate for breakfast, lunch and dinner. A special betta Pellet, such as Hikari or Wardley's provides good total nutrition and the bloodworms are a nice treat.  

This is what may have caused the lapse in your bettas' health. The raggedness of the fins sounds like finrot, and the swollenness is probably him gasping for air as a result of the stress.

Adding salt and changing water is the right thing to do - good job. :) Change 50% of his water daily, adding the salt, and if the rot increases or isn't receding in a week, get some good broad spectrum medication and add as directed on the package.

When the rot is cured, stop adding medication but do water changes every other day for another week to prevent relapse. Keep his water clean and warm (78-82 degrees) and keep up to date with your weekly 50% water changes.

Hope this helps!

Prue