If the fungus is worsening, yes, you might need to euthanize him. I'm sorry to have to say that.
As for why they keep getting fungus, did you get all your bettas from the same store? If so, it could be bad stock and/or bad care. If you try again, definitely find a new source. You might want to look for a local hobbyist breeder, or contact the ACers who have been breeding bettas recently.
ALL of the bettas have come from different stores. This is why I am so baffled! I have done everything right, but I keep killing them, and its breaking my heart.
I checked in at home today and apparently he is not doing so well, so I will have to euthanize him tonight.
Its so frustrating too, because I love the lil guys! they are so beautiful! They have some half moon bettas at this one store, and I would love to get one, but they are $20 and I refuse to pay that for a betta if its going to suffer the same fate as the others have.
