I appreciate the input. They have been in a tank together for about 4 months now and the eel seemed to be getting big quick so I wasn't sure if him or the ghost fish or rope fish would ever get big enough to want to snack on them. It is a ghost knife fish that is in there. I've had the clown knife fish before but they became very aggressive. They are in a 220 with a few small discus and mystery snails but the others didn't strike me as having an issue later.