Set Up the Breeding Tank

• 1). Follow the manufacturer's instructions to set up the 50-gallon aquarium, filter, pump, air stones, chiller and thermometer.
  
  
• 2). Cover the bottom of the tank with a 2-inch layer of pea-sized gravel.
  
  
• 3). Fill the tank with non-chlorinated spring water at room temperature. Turn on the chiller and bring the water to 55 to 58 degrees Fahrenheit if you're breeding trout. If you are breeding other species of fish, check with your local University Extension office to find out what temperature range they prefer.
  
  
• 4). Add the marbles to the tank. Allow them to settle on the bottom and then use the fish net to distribute them evenly.
  
  

Add the Fish

• 1). Add the breeding stock to the breeding tank. If you are using breeding stock from your own aquaponics tank, be sure the water in both tanks is between 55 and 58 degrees to minimize shock. If you have obtained breeding stock from a hatchery, follow the hatchery's instructions for adding the fish to your tank.
  
  
• 2). Feed the breeding stock live food two or three times per day. Do not overfeed. It is best to feed small amounts of food several times per day, as this minimizes stress on the fish.
  
  
• 3). Watch for spawning. When you see eggs nestled in the marbles, remove the adult fish and return them to the aquaponics tank.
  
  
• 4). Line the outside of the tank with styrofoam sheets and secure them with duct tape. This will insulate the tank and keep it dark, which the infant fish, or fry, prefer.
  
  
• 5). Carefully examine the eggs, looking for any that are opaque white. These are dead and must be removed immediately with the turkey baster. Do this once per day.
  
  

Care for the Fry

• 1). Once the eggs hatch, the baby fish will remain on the bottom of the tank and feed from the yolk sac. They will remain for seven to fourteen days. Watch for the first fish to rise off the bottom. When the first ones begin to swim, provide a very small amount of fry food.
  
  
• 2). Monitor the fish and continue to feed two to three times per day, gradually increasing the amount of food per feeding.
  
  
• 3). When the fish reach 3 to 4 inches in length, move them to the aquaponics tank.