capper

In our 46g community tank, we have 8 Cardinal Tetras. 1 of them seems to have developed a white coloring on its forehead and top fin and tail. Any idea what this might be and what I should do about it? Should I quarantine the fish? The trouble with that is that I know Cardinals are much more comfortable in schools. I am worried that a single Cardinal in a small 2g hospital tank may be counterproductive.

COBettaCouple

Do the white areas have a cottony look to them? If so, that's a body fungus and you'll want to treat him with an anti-fungus product like:
http://www.drsfostersmith.com/Produc...&N=2004+113021 - this is probably the safest one to use on a whole tank if you don't want to quarantine him.