Cardtetras w/black spots

[Shari]

First thank you all - my two tanks of Discus are doing excellent thanks to your input and info, as well as discovering Prazi which worked like a charm-even my wild is eating again!whew

However, one tank I noticed last night, which also contains 8 cardnal tetras for the past two years, three-four of them have really dark/almost black spots like under the skin. Not raised bumps but almost bruised looking - no particular shape to the dark areas either, on one might be elongated, another a bit more circular - my Discus don't bother them so don't 'think' it's a problem caused by them but more likely a disease issue? They eat and swim consistantly so don't seem to be sickly.
Can't send photo's but - Opinion please? ???

[Wahter]

if the patches are like grayish coloring could be Pleistophora aka "neon tetra disease" (not really a disease, but a parasite). Not easy to cure and spreads around among tetras.

More info:

http://www.fish-disease.com/Diseases/Pleistophora.htm

http://aquaworld.netfirms.com/Disease/neonziekte.htm

http://homepage.mac.com/steevward/PhotoAlbum7.html

[Shari]

Thanks so much - gawd this site and you all are so wonderfully imformative. Like the one attach. you sent more of a blackish color than grey on my tetras-I have to check for the other discoloration mentioned - but I'm 'hoping' it's the False Neon Tetra Disease the other attachment made ref to.
Maybe Kanacyn huh-it says wide spectrum- or for the few I have, compared to the tank ful of Discus they are with would I be better off disposing of and treating the rest of the tank just in case?