This Must Be Fin Rot, But.....

[notg2009]

Hi all,
One of the two bettas that my brother keep in a 2.5 gallon tank with a divider, has been showing signs of fin rot for about 10 days. I have been adding API Melafix for about a week now, but the betta is not improving at all; in fact he has got much worse. I started treating with Kordon's Ich-Attack about 4 days ago, but no improvement yet. The other betta is surprisingly fine! Any suggestions?

Here are some photos:
http/www.flickr.com/photos/notg2009/5641588236/
http/www.flickr.com/photos/notg2009/5641568628/
http/www.flickr.com/photos/notg2009/5641568896/
http/www.flickr.com/photos/notg2009/5641000545/

I appreciate any help you can provide.

 

[loraxchick]

Waterchange immediately. The water is very cloudy which makes me suspect ammonia. Keep up with waterchanges every day for at least two weeks. The blue guy has a pretty serious looking leision behind his dorsal fin. You should probably separate the sick fish and run a course of antibiotic meds, finrot is probably secondary infection to that sore spot.
Is the tank filtered? How big and how long has it been set up?
Cheers