I was looking into these A LOT for awhile and mostly just got negative feedback. Apparently they're really hard to keep because you've got to supplement food for them and it's hard to tell if they're "full." If they starve.. they'll die.. and then your water gets nasty and smells. Not to mention they're not much of an eye-catched cause they'll just burrow and you'll rarely see them. But man, they'll keep your gravel aerated.