Clean water is almost as important as what you feed them. They need to be fed several times a day and waste food fouls the water faster than it's believeable.
I do 50% water changes everyday for the first month. I also clean the bottom of the bare bottom tank with each
water change. Food can stick to the bottom and decay causing a slime that bacteria grows in. This bacteria will kill your fry.
Newly hatched baby brine shrimp, first bites by Hikari, Decapsulated shrimp, golden pearls all good foods for new fry.
Carol