Betta fish swollen gill
I bought a betta fish about 6 months ago. When I brought him home he seemed perfectly healthy but after awhile I started to notice that one of his gills was getting a little puffy. Other than that he seemed fine.
His condition got worse over time though. About 2 months ago he suddenly started resting on his side on the bottom of his tank and only moved to go back to the surface for air and food. His one gill also started to look very swollen. I did some research on swollen gills and ended up buying some medicine for the fish at the store as well as some freshwater aquarium salt. I'm happy to say that his personality went back to normal and he is very active again. He even makes a bubble nest once a week.
The issue is that his gill never went back to normal and I am worried that it could be harmful to him. Here are some stats about my tank:
Size: 5 gallons
# of fish: 1
Decorations: all live plants
Temp: usually around 78 degrees
Food: standard betta fish pellets plus the occasional dried blood worm or shrimp
Cleaning schedule: 50% water change every week, 100% every month
Products added to water: water conditioner, betta safe aquarium quick start, freshwater plant growth formula safe for tanks with fish, and freshwater salt
Items in tank: heater and filter
As I said, I tried a few treatments to help his gill but none seemed to help the swelling. At this point he is acting normal except for the fact that he does flare quite a bit. Other than that, he looks completely healthy and only one of his gills is swollen, the other one looks normal. There isn't even any red or irritated areas on his swollen gill, it just looks puffed up.
Is there anything I can do to help his gill?