It is important to keep he fry separate from the older fish, as young fish will be eaten by the more mature fish. The fry should be kept separate until they have grown enough to be able to hold their own with the older fish.
Maintain water quality, and feed your fry a healthy diet. Fry eat several times a day, and grow rapidly. Any non GMO algae powder or spirulina serves as an excellent food source for fry.