I always crushed up freeze dried bloodworms. They ate bloodworms well then when they got older I fed them flakes. Just test out multiple things and if they don’t like one thing then try another. I only kept mine in a separate container for about 3 weeks and they were pretty big then because it took me a while to discover them. Also if you don’t I would recommend buying a cheap turkey baster to suck the poop out of the adult tank. They tend to get a bit dirty if they don’t eat the food. Just make sure you don’t suck them up with it. Have a great day!