I've been lurking in these forums for a while now, since deciding to get a betta fish. I've had my boy (his name is Mir) for about three weeks now, and he's doing well except for one thing. It appears that his left gill is swollen so that he can't completely shut it. He's otherwise active and happy. He swims around, flares, and builds bubble nests, so I don't think he's feeling listless or anything. Environment info and pictures are below. I've read about gill disease and gill flukes, but I'm not sure whether it could be either of these, and how to treat it. Any ideas?
What size is your tank? 5 gallon
What temperature is your tank? Usually 27-30 degrees Celsius
Does your tank have a filter? Yup.
Does your tank have an air stone or other type of aeration? No.
Is your tank heated? Yup.
What tank mates does your betta fish live with? None. I want to get some ghost shrimp eventually though. xD
What type of food do you feed your betta fish? Omega One Betta Buffet Flakes.
How often do you feed your betta fish? Twice a day, usually one or two 1cm long flakes.
How often do you perform a water change? Once a week.
What percentage of the water do you change when you perform a water change? 100% or 50%, depending on how dirty the water is.
What type of additives do you add to the water when you perform a water change? Water conditioner.
Have you tested your water? If so, what are the following parameters? No, don't have a testing kit.
Symptoms and Treatment
How has your betta fish's appearance changed? Swollen gill.
How has your betta fish's behavior changed? Hasn't.
When did you start noticing the symptoms? A week ago.
Have you started treating your fish? If so, how? No.
Does your fish have any history of being ill? He's new, so I wouldn't know.
How old is your fish (approximately)? No idea.