wrote:
Right, I had heard about stress on fish before. Well, I did not see
the spot when purchased, but isn't just taking the fish and
transporting it hope reason enough for stress? My tanks parameters
are fine, its been an established tank for several years and has nearly
all the original fish in it for that time. I'll try the salt route
first. I recall something about doign a salt bath on the fish
itself.... how is that done?

It is possible that the conditions where you bought your fish differ
greatly from your aquarium parameters, and this can cause stress. Make
sure your Pleco has a dark quiet spot to hide in during the day. Make
sure you have a proper calcium level (test by measuring KH), as fish
need more calcium during times of stress.
As for treatment, I would second the suggestion of the methylene blue,
used as a dip at double the regular dose.
I have more information about methylene blue and other medications
he
http://aquarium-medictions.blogspot.com/

Carl