It is very important to have much plant cover for the fry to hide in as the adult fish will try to eat them especially if underfed and if not much other live food is given. The baby fry feed on small organisms called infusoria and algae. To grow infusoria for feeding just get a jam jar of pond water and run it through some cotton wool or muslin to get out any larger predatory organisms like daphnia which will eat the infusoria and add hay to the water.