Compared with delicate tropical fish, hardy guppies are simple to care for. They need a regular feeding schedule to stay healthy and happy. Adult guppies are easy to work into a morning and evening routine, but baby guppies' need to eat often dictates spreading several feedings out throughout the day.
Feed adult guppies once or twice a day. At least one meal should consist of live food. Unlike young fish, whose frequent meals support rapid development, adults function well with fewer meals. Transition young guppies to an adult feeding schedule at about 3 months of age, after they have finished their intense growth period.
Guppy babies, or fry, need feeding between five and eight times each day. This is because their bodies go through rapid changes and are constantly growing. Since the tiny fish can eat only so much in a single serving, they need a lot of small meals. Giving a lot of food at once is not the answer, since much of it will remain uneaten and dirty the tank. Inadequate feeding can stunt growth and affect a guppy's health as an adult.
Water temperature has a significant impact on a guppy's appetite, especially fry. Cool temperatures make the fish sluggish and as a result, they consume less food. Warmer temperatures increase activity and appetite. While it isn't necessary to spark an adult guppy's appetite, young guppies kept in cool water may not eat enough to grow properly. Ideally, a tank should be kept between 76 and 80 degrees Fahrenheit for baby guppies.
Overfeeding can cause serious problems, up to death, in guppies, so it's as important to feed the right amount as it is to feed on a regular schedule. For both adults and fry, feed only as much as the guppies will eat within a couple minutes. If food remains after that time, reduce the amount offered at each feeding.
Provide adult guppies a combination of dry flakes and live food such as brine shrimp, chopped earth worms, fruit flies, blood worms and mosquito larvae. Freshly hatched brine shrimp are an ideal source of food for young fry, who should receive some protein-rich meat in nearly every meal. You can feed ground dry food flakes, microworms and ground frozen beef heart. Food for fry should be chopped or ground very fine so they are able to eat it, especially during the first 6 weeks.