Dealing with columnaris now, looks just like that.
Originally Posted by @marko@
minocycline (maracyn 2) is really weak against columnaris. this is a strong, rapidly spreading disease.
use kanamycin (seachem kanaplex) or if you cant get it sulfathiozole (API triple sulfa, or seachem sulfathizole). i have used both against columnaris, and both worked. salt can also help, as this bacteria doesnt like salt.
DO NOT RAISE THE TEMPS. this bacteria preffers high temps, like 78-86. and it will spread much faster. some people actually advocate lowering the temps for this reason, but i just leave it alone.
Read this thread...