To help with feeding.
Turn the lights down low...
Feeder stick with Silverside, krill or another food source on the end.....
Find some current and wiggle the food at the top of the water, in the current. I never had much trouble feeding lions.
If that doesnt work, soak the food in Garlic Guard and repeat above.
You can go a week without feeding the fuzzy if its healthy. Sometimes, from what I've read, it can take a while to get them to eat frozen. It might help to starve him a couple of days before trying.