How to Breed Fancy-Tailed Guppies

Choose a location for your aquarium. Even a 10-gallon aquarium will be heavy when full, so make sure it's in your desired location before you begin the setup process.

Install a filter and heater. A large-size box filter or an outside power filter is preferable to an undergravel filter. A heater is necessary to maintain the tank at a constant temperature since even a small temperature change can be stressful for the fish.

Fill the aquarium with water and add a dechlorinator if desired. Alternatively, make sure that any tap water you use has been sitting out for at least 48 hours so the chlorine in the water can evaporate. You may also choose to add a well-washed gravel substrate to the bottom of the tank, but this is optional. The gravel provides extra surface area for beneficial bacteria to grow and it also increases the attractiveness of the environment.

Contact your chosen reputable guppy breeder for information about the water the fish are raised in and try to replicate the pH and chemistry of that water as closely as possible. The pH of the water can be tricky to adjust for those new to the hobby. Since sudden pH changes can harm fish, you may want to see how they do without any pH adjustments first. Guppies enjoy medium-hard, alkaline water.

Adjust the temperature of the water. Adult guppies need a temperature between 72 and 76 degrees Fahrenheit, while fry grow faster if the temperature is in the 78 to 80 degree Fahrenheit range.

Order quality breeding stock from the reputable guppy breeder. Choose healthy, full-sized fish from different broods to avoid genetic problems from inbreeding. Avoid buying your fish from pet stores if possible -- they're either usually raised overseas in large commercial tanks or culls from the reputable breeders.

Select one or two trios of fish. A trio consists of one male and two females. This combination will ensure that these live bearers will drop lots of baby fish, or fry, all at once.

Acclimate your fish. Take the bag with the fish in it and open it up without letting any fish or water out. Place it in the tank and secure it to the side of the tank with a clip. Every ten minutes or so, remove a little bit of the original water from the bag and let a little bit of water from the tank into the bag. After about an hour, you can let your fish swim freely in the tank.

Set up the birthing tank and install a sponge filter, which is safe for the fry. The birthing tank should not have a gravel substrate since it is easier to see the fry without one. Fill it with halfway with water from the old tank, then fill the remainder with dechlorinated tap water. The birthing tank should be between 2-1/2 and 5 gallons. Place plants in the bottom of the tank to give newly-born fry a place to hide. Many females are cannibalistic. Plants may be real or plastic. In fact, many pet stores sell finely-bladed plastic grass intended for this purpose called breeding grass.

Observe the female fish closely. The gestation period is usually about 28 days. Sometimes female guppies will arrive "pre hit" and ready to give you baby fish at any time. Right before she's ready to give birth, the female guppy will swell in size and a dark spot will form near her anal fin. The dark spot is called the gravid spot. Examine the shape of the anal area near the gravid spot. When the the female is very close to given birth it loses its round shape and becomes almost square.

Move the female guppy to a new tank when she appears close to giving birth. The female guppy will often appear agitated and unsettled. Sometimes she'll even turn a darker color. When it comes time to give birth, her body may curl as she pushes out the tiny fry. Older females can give birth to two to three fry at once. Fry will generally be clear or gray when born -- they develop their spectacular colors later.

Remove the female from the tank soon after she gives birth.She'll be thinner and less agitated after the process is finished. She'll also be hungry. A high-protein food source, such as baby brine shrimp, will help her recovery more quickly.

Feed the fry. They enjoy live or frozen baby brine shrimp, fine flakes of baby fish food, cooked egg yolk and microworms.