Is this fin rot?

[Fishyfriend09]

Long story short i went to spend the night at a friends house and came back today to find half a dozen dead fish so naturally i tested the water quality and it was exactly as it always has been. I have also just noticed my male sailfin molly has something weird happening with one of his side fins. i have added a few photos hopefully you guys can help me out. Thanks =)

If it is find rot i heard that methylene blue can be used as a treatment or along with another treatment, is there truth in that?

 

[i3k]

can't tell from the pics. use melafix and pimafix if it's fin rot.

 

[Fishyfriend09]

unfortunately he didn't make it , shame i didnt find out what was wrong, keeping a close eye on my other fishies for the moment but hopefully all should be fine

 

[dkpate]

It looks like an advanced version of what my harlequin rasboras came home with. I lost 5 before I realized what was going on. I treated the tank with Melafix and the 2 that were left and still going strong. I would do the Pimafix and the Melafix though, like i3k said though, just to be safe. It sort of looks like a fingus too, which could be a secondary thing, after a fight.
Sorry about your fish.

 

[Zagz]

Sorry for your loss. As mentioned melafix and pimafix would not hurt your tank and might be a good idea. Just incase.