use the feeder buckets. they have tiny holes in them so the eels can suck the worms out. they will also fall out slowly cuz of the current etc. and you can stick it to the glass near the surface. i also use this to put in regular worms so the eels have something to do.
that looks awesome im still looking for one so far no luck..... how big is your tank that has to be at least 500 gallons.....