Then try frozen beef heart. Less messy and has lots of nutrition for a baby aro. You can even go to a butcher and buy it by the pound for cheaper and cut it up yourself. Just be sure to remove any extra from the tank that doesn't get eaten. Or get a bichir who will eat it
As I stated before, Freeze dried blood worms are best. They float for quite awhile so un eaten are easily removed and won't foul the water. They are soft so are easily consumed by the baby aro and they are nutritious.
try crickets or small grasshoppers.new aros can be stressed when people approach the tank.when you feed it walk away from the tank.after a while it will get used to you.hope this helps.