Hi, Last week I was in my local Petco and I saw a male king betta and I fell in love. I had to wait a few days to purchase the little guy. When I went back I saw that he was laying on the bottom and his gills were swollen and red underneath. He was also gasping for air and would, every once in a while, dart to the top of the bowl and gulp air, or so it looked. I informed a petco worker and she said that I could purchase the fish and if anything happened within 30 days I could bring the fish back and get a refund. She agreed that he didn't look well. I asked her if she or anyone else at Petco would treat him and she said that if I left him he probably wouldn't be treated. I got the impression that they would just leave him there and if he got purchased great but if he didn't then they would be content with letting him die. I decided to buy him and try to treat him and if he died, at least I had attempted to save him. I took him home and placed him in a gallon hospital tank with fresh water. I read online that often times swollen gills are caused from ammonia poisoning, so I wanted to get him in fresh water as fast (and as safely of course) as I could. I also added some salt and Melafix for bacterial infections. I have Maracyn two as well, but I haven't added it yet. How best do you treat inflamed gills? Also, can I add Maracyn two to the Melafix already in the tank or do I have to do a 100% water change before I add it? I read that ampicillin is best for inflamed gills but my pet store only carried Maracyn two. Thank you for any help!