I have had one for over 3 years now, I originally got him as a room mate for my fuzzy in a 30g. About 1.5 years ago I put them in a 90g and added a zebra and an antennata. I feed my lions live food, mostly ghosties, sometimes molly babies, an occasional guppy, and once a month a peppermint shrimp.
Some people also suggest they like cooler water, although my tanks are 80.6 during the summer. I acclimated him from 76 to 80 over the course of 2 weeks. My fuzzy was a rescue and only ate live, I've had him 4 years now, the fu was only eating live when I got him. So now I keep a ghosties tank, gut loaded with marine pellets and soaked in brightwell aminomega before feeding.
I think they are best in a species tank, he is very active in the 90 with 3 other lions and eats like a champ. He will occasionally take a piece of dead food and will swim right up to me and take it from my hand. Although many people believe in weaning them to dead food, I believe they are more active and even satisfied when they are stalking and hunting. It also makes for a much more entertaining tank. I have also never met anyone in person nor have heard from one of my lfs of anyone ever keeping them long term on dead food.