Step-by-Step Instructions for a Cycling Tank With an Established Filter

Cycling a new aquarium is a simple process if you have access to an aquarium filter from an established tank. Established tanks have a healthy population of bacteria that break down fish waste and keep the aquarium water clean and safe for your fish. Many filters are designed to house large numbers of these beneficial bacteria and using an established filter greatly reduces the time it takes to fully cycle new aquariums.

Things You'll Need

  • Aquarium
  • Aquarium gravel
  • Aquarium filter
  • Fish food
  • Aquarium chemical testing kit
  • Record book
Show More

Instructions

    • 1

      Rinse aquarium gravel thoroughly to remove loose sediment and particles from the rocks and then place in the aquarium.

    • 2

      Fill the aquarium with tap water and allow to sit for 24 hours to allow the water to dechlorinate naturally and the remaining debris from the gravel to settle.

    • 3

      Install the established aquarium filter to the new aquarium and plug in to a power source.

    • 4

      Add a few starter fish to your aquarium to test out the filtration rate of the established filter. Hardy species such as tetras, barbs and loaches are resilient fish that can tolerate the changing water chemistry of new tanks well.

    • 5

      Feed the fish lightly several times each day. Do not overfeed the fish since uneaten food can contribute to spikes the ammonia and nitrates in new tanks, which can stress or even kill the fish in the aquarium.

    • 6

      Test the water chemistry of your aquarium each day after you introduce the fish. An established aquarium filter should be able to handle the waste from new fish without problems, but it is still important to make sure that the tank is developing the proper bacterial colonies to support more fish in the future.

    • 7

      Write the chemical levels for nitrates and ammonia down in a daily record book. The nitrogen cycle in new aquariums usually sees ammonia levels increase in the beginning followed by an increase of nitrites. Once both chemicals have spiked and then faded from the tank -- 0 parts per million is the ideal number for both chemicals -- the aquarium is fully cycled and ready for the addition of new fish.