If this helps.
What size is your tank? 2.5 gallons
What temperature is your tank? 78 degrees
Does your tank have a filter? No
Does your tank have an air stone or other type of aeration? No
Is your tank heated? Yes.
What tank mates does your betta fish live with? None.
What type of food do you feed your betta fish? Aqueon Betta Food (pellets), and TopFin freeze-dried blood worms once a week.
How often do you feed your betta fish? 3 pellets in the am and 3 in the pm, bloodworms on saturday and I skip feeding on Sunday.
How often do you perform a water change? 100% weekly
What percentage of the water do you change when you perform a water change? 100%
What type of additives do you add to the water when you perform a water change? Top Fin Water Conditioner
Have you tested your water? If so, what are the following parameters? No
Symptoms and Treatment
How has your betta fish's appearance changed? Yes, his fins aren't the same and there is a bit of coloring difference.
How has your betta fish's behavior changed? I don't think so.
When did you start noticing the symptoms? Less than a week ago.
Have you started treating your fish? If so, how? No.
Does your fish have any history of being ill? No.
How old is your fish (approximately)? Well over a year, I'm not sure exactly.