While this may seem like a cruel practice, guppy fry are actually born fully prepared to survive on their own. Also, as stated about, mother guppies can occasionally become cannibalistic and will eat their babies. If you are not able to be there when your female gives birth, make sure to provide the fry lots of aquarium plants to hide in. Fry need to live in a tank that is around 78 degrees F (25.5 degrees C.) Keep your tank at this temperature until the fry are fully grown. The tank will also need to be cleaned often. Siphon the tank carefully every time it gets too dirty and do 40% water changes every few days to keep the water clean. Guppy fry eat brine shrimp, micro-worms or powdered flakes. They should be fed twice a day. Guppies enjoy both meat and vegetables. You should feed your guppies vegetable flakes, as well as standard flakes. Remember that fry are tiny and if you place too much food in the tank, the excess food that goes bad while sitting in the water could make your fry sick, or even kill them. Newborn fry should be fed recently hatched brine shrimp so that the guppies reach their greatest growth potential. If you want to give your guppies a treat, place a small amount of boiled spinach in their tank. This means removing any fry that have died. Dead fry will float to the top of the tank, making it easy to scoop them up. Keep track of how many fry die. If you notice that there is a high amount of fry death, you will want to figure out what is killing them. Change the water and switch to a different type of food. Any accumulated waste is bad for guppy health. When the fry are a good size, or about a month and a half to two months old, they will be ready to fend for themselves outside of the breeding tank. You can put them into your normal tank with non-aggressive fish, sell them to your local pet store, or give them to friends as gifts.
Remove your female fish from the breeding tank once the fry have been born. Keep the tank clean and at a healthy temperature. Feed the fry the right food. Take steps to ensure that your fry are healthy. Move the fry to the normal tank when they get big enough.