How to Cycle a 10 Gallon Tank

Adding fish to an aquarium that has not been cycled is a recipe for disaster. Ammonia, nitrites and nitrates are toxic byproducts of fish metabolism, and they can quickly overwhelm an aquarium -- causing illness or death to its inhabitants. Beneficial bacteria convert these toxins into less toxic substances, but these bacteria are not present in a freshly set-up aquarium. Cycling is the process of establishing enough of these bacteria to keep toxin levels low. The simplest way to cycle an aquarium is "fishless cycling," which establishes the bacteria population before any fish are added to the aquarium.

Things You'll Need

Water testing kit
Aquarium-grade ammonia

Instructions

- 1
  Set up your aquarium with the necessary supplies for the fish you intend to keep, including things such as substrate and shelter. Transfer gravel, ornaments and filter mediums from cycled tanks into the new aquarium, if practical. This will transport beneficial bacteria from those tanks and speed up the cycling process. Use an aerator -- such as an air stone -- or a splashing filter outflow to aerate the water.
- 2
  Adjust the water's pH and temperature to appropriate levels for the fish you intend to keep. Use a heater to raise water temperature, and float sealed bags of ice water to lower it. Add chemicals to adjust the water's pH level, and use a water testing kit to monitor the results.
- 3
  Add five drops of aquarium-grade ammonia to the water every day. Test the water daily for ammonia and nitrite levels. Reduce the daily ammonia dosage to three drops, once nitrite levels are detectable by the testing kit. Continue adding three drops of ammonia each day, until both ammonia and nitrite levels are no longer detectable.
- 4
  Add fish to the aquarium as soon as possible, after ammonia and nitrite levels are no longer detectable. If a delay is unavoidable, continue adding three drops of ammonia to the aquarium each day, to maintain the bacteria population until fish can be added.