Peter,
Hardest part is getting them to eat.I had a blue ribbon eel for almost two years. I fed it silversides, krill both soaked in zoe, zoecon, and garlic.
When I first got him, it took him 7 weeks before he started to eat. Six months after that he was eating from my hand. This was in a FOWLR set up, not a reef.
He ultimately met his demise only as a result of a giant red hermit crab I had caught his tail, mucnhed on it, and he wound up bleeding out.