i have one TT eel about 8-9" and two fire eels about 6", ive had them 5 months and there awesome fish! they all will eat out of my hand but there a pain to feed, the only foods the fires will eat are live earth/black worms the TT will eat cooked shrimp now witch is way easier(and sence hes been eating it hes grow a lot longer and fatter), they all live in a 38g togeather and there isent usualy any fights the tt and the bigger fire eel live under a 6" clay pot thats upside down(they take turns sticking there heads out the hole in the bottom to look around)and the small fire has another pot with a hole in one side, they havent tried to get out that i know of but i did have another tt that jumped out before so you should keep alid on them.