How to Cycle a Fish Tank

Ensure a healthy, balanced environment in your aquarium by following this simple process.

You will need

  • A fish tank
  • A filter
  • Hardy fish
  • Water samples

Step 1 Set up fish tank Set up your fish tank and filter system, then fill it with water.

Step 2 Stock with hardy fish Stock your tank with hardy fish, such as mollies, tiger barbs, white clouds, or guppies.

Step 3 Limit the number Put in just a few fish. Three 1-inch fish are sufficient if your tank is between 10 and 20 gallons.

Step 4 Change the water Change 10 to 15 percent of the water every few days.

Step 5 Test a water sample Test a sample of the water after a week. It should test high in ammonia with a trace of nitrate at this time.

Step 6 Continue the process Continue moderate water changes every two weeks. Cycling a tank takes up to eight weeks. Your goal is to establish a healthy colony of bacteria that live in the filter, removing ammonia and other toxins from the water.

Step 7 Add more fish gradually Add more fish gradually, and enjoy watching them thrive as a result of your diligence.