Help! Treatment question!

Hello everybody

I'm new in this group and already I desperatly hope somebody could help mea
out with some good advice.

I have a 500 liter tank with mainly SOuth american fish and 4 adult "rubber
eels" (Typhlonectes compressicauda). This tank has run vrey well over the
last 4 years or so, until last week, when a few fish died. I have a
microscope at home and so I was able to detect the parasite Trichodina. Now
the parasite itself wouldn't be a huge concern, since I know that a
treatment is possible - but how about the rubber eels? Which product is
recommended in such a circumstance?

I really hope somebody has got some experience and could help me, I really
hate the idea of loosing these animals as a result of a treatment.

Thanks a lot in advance

Olivier