hi guys since I don't want a stingray or a bichir for a bottom feeder I recently saw some fire eels and I tought wow what a looker but I read they where burrowers what came to mind were khuli loach which you never see so my question is can I just provide it a plastic cave then have no substrate for it to burrow so I can see it more often so guys is it ok to keep fire eel with no substrate? Hehe