I wouldn't use bettafix. It contains tea tree oil which damages the labyrinth organ. And the mystery disease is just that... A mystery. I would say this isn't it because he is still alive after 24 hours..
That mystery disease definitely looks him, and it sounds like what happened. It came on so fast, I'm assuming over night, as when I went to bed he was fine, but in the morning his fins were all black, like some one had taken a match to him.
I notice in the thread they point out thier betta were euthanized, not that they had passed due to the mystery disease. Perhaps he's only alive because I've not given up on him. He gets around well, and acts normal, if he was acting pathetic and lethargic I may, but he isn't so as long as he's willing to fight, I'll try for him.
I'll definitely pick up stress coat, a ph and levels testing kit on the way home from work, and check to see if I can get a heater as well
Yes, it looks an awful lot like the mystery disease but I don't think it is. It spreads rapidly from the tip of the fins to the body and kills within 12-24 hours. Even experienced keepers were unable to help their bettas.. Many people have also reported it as the cause of death of their fish. As of present, it's not treatable because they have no idea what it is.
Well, I'm not any sort of expert, but we don't know what causes the disease. Maybe it's water poisoning of some sort and Jayoen took him out in time. Or maybe it hit him but he has some immunity or something in his genetic makeup that makes him resistant. Based on the pictures in the mystery disease topic and here, what he had looks really really similar...Just because it didn't act quite the same way doesn't necessarily mean it's not, right?
Stress coat and increased heat won't cure this, although it will be helpful.. he needs a good antibiotic. Really strongly suggest getting Kanaplex. That's also what the sticky suggests for the mystery disease.
If used correctly Bettafix will not kill your fish. It may have the same properties as Melafix and Primafix but it's not the same. I use Betta fix often and have never had any problems with it hurting my fish, while Mela and Prima (out of desperation) have killed the fish I've used it on within a 24 hours. It does indeed destroy their ability to breathe air as it was very clear that my boy was drowning since he was basically jumping out of the water to get air.
At any rate, the mystery disease i've seen kills between 12-48 hours, usually quicker but i've seen it go for 48. Only acouple times i've noticed people had to put their fish to sleep others died from it consuming their body within hours. I hope this isn't the problem with your guy and that he recovers but it's really hard to tell what exactly is happening. Has it gotten worse at all and can you post any more photos?