Betta With Fin Rot

[neverlonelyalone]

I just came back from a five day trip where i left my betta with a friend. When i got back, i noticed that the dorsal fin was completely gone and there was an exposed white patch underneath. A little drop of red (blood?) squeezed out. Right away i changed the water and put a little bit of hydrogen peroxide in the tank. The temperature is around 76-78 degrees. Is there anything else i can do to help my baby?
5 gallon tank
my fish is feisty and acting normal

 

[Platy lover]

I read this on Y!A. Please change the water immediately, it could very well kill him. Please in the morning buy stress coat and change his water every few days until it heals