Well, I've never had them but.... What do you feed the adults? Just powder the adult food and give it to them, or use flakes, again finely crushed. Its what I do for my guppy babies.
Pulverized flakes and you can buy fry food at stores. Hope you have lots of hiding places for the babies so mom doesn't decide they would make a tasty meal.
You can buy food for baby fish at a fish store, or crush up the adult food into a fine powder. I find that buying the food for babies at the store is better for them, though and they eat more.