Before we all start recommending a new eel, what happened to your old one? This might hlep us find you the right eel for you, your tank water parameters, and ultimate tank size. You mentioned that he didn't grow very fast. I just posted this in another thread:
"On the correct diet they grow fast. My guys went from a skinny 6-7" to 17-18" in one year. My larger guy I got very skinny and he put on good weight and great from 18" to 24" in a year. Too often people think that a diet of blood worms is all they need. If they aren't growing at a good rate, then they are being fed a good diet and will eventually die. I've never heard of an eel accept pellets, but my two smaller guys grew up eating red wriggler earthworms, bloodworms if they wanted, frozen Hikari krill, chunks of steamed market shrimp, and now chunks of steamed tilapia, and huge nightcrawler earthworms. My bigger guy is much more picky he will not eat krill unless starving, and that he'll choke down like one or two pieces. One of my smaller eels is a severe pig and will try to eat anything, but still wont eat pellets. I actually put him on a bit of a diet. He started to look like a sausage the couldn't look down cause he kept stealing everyone's food. My eels are my favorites. "
Fire eels are great, but they do get big. I really don't think a 30+" and beefy fire eel would be that happy in a 75ga. Mine are in a 180 and incredibly active. But, they are GREAT fish that I'm plenty happy to go to the bait shop every few weeks for. Of all my fish they are the most fun to feed, and Norbert, my big guy, has learned that he likes to sit in my hand so he can lazily stick his nose out of the water. As mentioned before, they need softer water, a lower pH (I keep mine at about 6.6-6.8), and I keep mine at about 78-80 degrees temp. If you think this works for your tank, then yeah, I'd get a fire eel.
