Those eels really like to burrow in gravel and sand. Rough large pebble gravel can cause abbrasions and open sores on their skin. They're also really sensitive to medications and drastic water quality. Very picky eaters, and you want to probably pick up a live worm food diet for them. I had a tough time weaning mine onto freeze dried tubifex, so that is not the way I would reccomend to go. But they really relish live worms (and so would the rest of your fishies). Put in a section of strait, clear, Hamster Habi-trail in the tank with some rocks stacked around it, and see if they'll take to that instead of burrowing.
Oh, BTW, they can grow up to 14" so you might want to think a bit about a bigger tan.
~~Colesea
