is this tail rot?? :(

[duendecillo]

I just noticed this brownish spot on his tail, do you think it's tail rot?
If it is, what should I do about it?
It's my first betta, I only have him 3 days...

 

[duendecillo]

maybe a better view on this one...

 

[HeatherSweetness]

Yup. That's tailrot.

I treat my bettas tailrot with aquarisol and salt. I've used melafix and fungus guard,also. When I see the rot gone and see the fins begin to heal,I add methylene blue to the water to keep it gone.

* I only add the meth blue for a week after the rot is gone. After that,sparkling clean water and salt.