Best food for newly hatched fry is Paramecia. Easy to culture and a great way to see stupendous results. 

The best food for newborn small fry is infusoria.  One species of infusoria is Paramecia which belong to the ciliates. Their entire surface is covered with cilia, or eyelashes, which the paramecium uses to swirl food around and also to help it move around.  Paramecia feed mainly on bacteria and sometimes also on other unicellular microorganisms, such as unicellular fungi like yeasts and also unicellular algae.   A complete kit for starting paramecia or paramecium is included with video link instructions on how to propagate and keep on hand permanently.