Hydrogen peroxide for Fin Rot? Or any tips?

Can I use hydrogen peroxide externally?
Yesterday I bought a small colony of albino full red guppy, and the breeder male, a male with a huge tail has a small segment of fun decaying... I've read that people have physically applied hydrogen peroxide to a cut before with a lot of success. I need all the tips possible to not killing my fish for I accidentally did once when the fish flopped.... Should I wait to apply the hydrogen peroxide? Or should I apply it now ( remember he is a new fish ). How do I stop him from moving and stop the hydrogen peroxide from going to his gills without stressing him?
Thanks I advance for any tips!



You can kind of see his cut, ( he is very active so kinda hard to take pictures )

Also, he has a small white spot on one side of his body, I contacted the guy I bought him from and he said that it was there the day he got him.. Could it be collumaris?... I am gradually introducing salt to the tank.

 

Bumping this up for you

 

Update: tried applying hydrogen peroxide physically with no prevail... Fin rot seems to be getting worse... Any tips? I currently have only neoplex kenaplex and salt on hand. The male is in a 50 gallon so it's too large to treat and I don't currently have a quaratine ready...

 

I also have a national geographic herbal fungal treatment... Anyone know if this works??

 

With such a large tail, there is no blood supply to it. SO it rots. This is normal and no cause for concern
Usually not fatal either.
There is a lot of controversy on whether the tea tree oils work or not. Personally I would take him out and give him a few days in a smaller tank or tub if he is some prized breeder. Even a goldfish bowl or mason jar
This is what you want to use

Dont add it to the main tank as it kills everything, but its GREAT for wounds, fungal infection of eggs and tail rot that results from inadequate blood supply to the tail as in large delta tailed fancies like him.
It will also help him recover from the trip in the small bag, which likely gave him a touch of ammonia and nitrite poisining.

 

With such a large tail, there is no blood supply to it. SO it rots. This is normal and no cause for concern
Usually not fatal either.
There is a lot of controversy on whether the tea tree oils work or not. Personally I would take him out and give him a few days in a smaller tank or tub if he is some prized breeder. Even a goldfish bowl or mason jar
This is what you want to use

Dont add it to the main tank as it kills everything, but its GREAT for wounds, fungal infection of eggs and tail rot that results from inadequate blood supply to the tail as in large delta tailed fancies like him.
It will also help him recover from the trip in the small bag, which likely gave him a touch of ammonia and nitrite poisining.

Thanks for the great info!