I have had my better since October last year. He has been in great shape since I've had him and was always happy building bubble nests. 3 days ago, I noticed he stopped eating and was a lot quieter than usual.
I spotted a small white lump under his gill near his front left fin. It seems to move as his gill and fin moves...
I keep him in a 1.5 gallon bowl (I have just bought a bigger one for him but don't want to move him until he is better). I do a 100% water change once a week and have a plastic fish plant in with him. I use a water conditioner everytime I change his water and over the last 3 days I have been giving him Bettafix. I changed his water once he became sick and nothing seems to have helped.
He just sits at the top of the water and hardly moving. I also noticed he uses his left fin less when swimming (where the lump is).
Having done a lot of research, I wonder if it might be a parasite from some frozen blood worms I fed him...
Any ideas, what medication/treatment I should try??
Attached is a picture of the lump (which seems bigger this morning)