Microworms and vinegar eels are fine. Even most larger fish can't pass up live food, no matter how small. I make egg yolk flakes, it keeps the tank cleaner. Or you can smear some on a rock, bake it and then leave it in the tank for a while for foraging.
The goal is to offer as varied a diet as possible and to feed often and do frequent water changes. Unless the fish is very cold or very sick, it's eating.