Everyone on the list seems to be in favor of Oto's as algae eaters.  Over
the years, I have had many experiences with them, very few of them were
overwhelmingly possitive.  They seem to have a habit of dying for no good
reason, even after months of good health, and I have not been particularly
impressed with their capacity to eat algae, but enough complaining and on
with my question.  I have four Heckel discus in my 110 with an apparently
very appetizing slime coat for I have witnessed on several occasions an Oto
leaaving its perch on plant or driftwood and start sucking on a discus like
some kind of upside-down remora.  Needless to say, this has been stressing my
discus.  In the past when I've had a problem with a fish eating the wrong
thing, I've made sure there was plenty of the right thing, well in this tank
I feed plenty because of the Discus and there is always some algae somewhere.
 Please help, I'd even consider an Oto-specific ichthyocide.  (BTW, I was
forced to go with Otos because the SAE well had dried up)