How Long have you had him?? Some eels won't eat for a while when first purchased. I feed my eels krill silversides and a variety of forzen seafood from the grocery store. If you can avoid it try not to give them freshwater feeders but if you have no choice ghost shrimp will be best
I feed mine table shrimp, medium size with the shell on. I have a feeding tube that I stick the shrimp in and put it in front of him. of course raw as well
3 days is no big deal mine usually wont eat until at least 3 days after a few cocktail shrimp(raw, shell on , and not devaned). it took almost 9 months to get mine to eat anything more than shrimp and live crawfish(as a treat).