I've got 2 fire eels with my silver, and they get on fine although he does look interested in them at dinner time as they swim to the surface to get their fair share of the food going in. The problem I can see that you will have with the jar, is that he will show a lot of aggrssion towards them at feeding time. Although they may currently be a foot and a half long, they are still a very tempting bite as they are sussage shapped and fit in the mouth easily.
Good luck with your choice,
Mike.
Good luck with your choice,
Mike.