Instructions
Start with a small, bare tank. A five-or 10-gallon aquarium works well as a breeder tank. Place a small amount of gravel on the bottom of the tank, but avoid any other decorations.
Place a small box filter in one corner of the aquarium. Avoid power filters, because their intake tubes could accidentally pull in the small fish fry as they swim by.
Hang a breeder box inside the tank. A breeder box is designed to provide a safe place for the fry to swim, safe from larger fish who could view them as tasty snacks.
Purchase fry food from your local pet store. Newly hatched fry have different nutritional requirements than adult fish, and fry food is designed to give those baby fish the nutrition they need in a readily digestible form.
Add a mat-type plant to the aquarium to give the newly hatched fry a place to hide. You can purchase artificial plants designed to float on the top of the tank, or you can use a dense plant such as Java Moss. Java Moss is a good choice for breeder tanks, since it grows quickly and provides excellent cover for smaller fish.
Place a few breeding pairs of fish in your tank and watch closely for signs of pregnancy in your females. Livebearers such as guppies and platies will give birth to live fry, while other fish lay eggs and wait for them to hatch.
Remove the adult fish from the tank when you see the newly hatched fry, unless you have a species that cares for its young. Most fish do not need to provide care for their fry, but others, like cichlids, do provide parental care. Research the type of fish you are dealing with before attempting to breed that species of fish.
How to Set Up Breeder Fish Tanks
Breeding your own fish can be very rewarding for both new and experienced hobbyists. Some fish, including livebearers such as guppies and platies, breed quite easily. Other fish are more challenging, but successfully breeding those species is that much more rewarding. Before you attempt to breed any fish, however, you need to set up the proper environment for those fish to spawn.