How do you keep baby guppies alive?

Separate newborn guppy fry from the adult fish immediately to prevent them from being eaten. Newborn fry do not need food for the first 2-3 days; then feed them brine shrimp, paramecium, or boiled, crushed egg yolk. If you have many fry, buy brine shrimp eggs and hatch them yourself. Once the fry reach about 2 cm, switch to regular fish food. Change water regularly: let fresh water sit in sunlight for about three days, keep one-third of the old water, add two-thirds new water, and change about once a week.