Columnaris?

[Grundy]

I just noticed that one of the corys that is in my quarantine tank has a fuzzy spot just behind his dorsal fin. There are no other spots and his mouth and gills look fine. He is acting normally as are the other fish. Does this sound like columnaris? If so, will this respond to malachite green or should I get some true antibiotics? BTW, water parameters are perfect (0,0,10, PH 7).

[ET1]

Columnaris is a bacterial infection. I used Maracyn for 10 days and it cleared it up when my cory had it.

[Grundy]

No other comments or thoughts?

[tmtpowers]

Sounds like it could be fungus as well... Pictures would help a lot or a better description.