So i purchased a 4inch fire eel for my freshwater aquarium which is 40 gal. At the time of the purchase i was unaware that it is "recommended" to use sand or soft gravel for the eels because they habitually bury themselves. What i have in my tank is regular blue aquarium gravel. My fire eel however does have one primary rock -cave he has claimed as his own, as well as several driftwood of varying sizes. Ive had him ( assuming hes a boy for about a 2 weeks now and so far so good. I watch him constantly and check to see if he has any wounds and he appears to be healthy ( although i dont believe ive witnessed him eat his bloodworms yet ). My question is this, is there anyone out there who was / is able to maintain a healthy fire eel with regular aquarium gravel ? and if so how long did your eel last ? thanks so much