How to Cycle a New Aquarium

Grounded in cited manufacturer & reference sources · AI-assisted, human-reviewed · Educational information, not professional advice.

To cycle a new aquarium, understand the nitrogen cycle where ammonia is broken down by bacteria to nitrite then nitrate. Monitor ammonia levels; if present, stop feeding and use an ammonia reducer. Only safe ammonia level is zero. [1] [2] [6] [7] [8]

Understanding the Nitrogen Cycle

The nitrogen cycle is a series of events that happens after you fill your aquarium with tap or bottled water for the first time. It is the biogeochemical cycle by which nitrogen is converted into multiple chemical forms as it circulates among atmospheric, terrestrial, and marine ecosystems. Important processes include fixation, ammonification, nitrification, and denitrification. Ammonia is broken down by nitrifying bacteria to nitrite and then nitrate in the Nitrogen Cycle. Both ammonia and nitrite are highly toxic to fish. It is common to notice the water gets cloudy during this cycle. [11] [13] [14] [15] [1] [2] [12]

Managing Ammonia Spikes

Steps to Cycle a New Aquarium

Common questions

What is the nitrogen cycle in an aquarium?

The nitrogen cycle is a series of events after filling your aquarium with water, where ammonia is broken down by bacteria to nitrite then nitrate. It is a biogeochemical cycle involving fixation, ammonification, nitrification, and denitrification. [11] [1] [13] [15]

How do I reduce ammonia in my new aquarium?

Stop feeding your fish if ammonia is detected, and add an Aqueon AquaPacs Ammonia Reducer after adding new water. Aqueon PURE spheres can also be used as they are pre-measured and cannot be overdosed. [7] [8] [3]

Why is ammonia dangerous for fish?

Ammonia is highly toxic to fish. High levels make it hard for fish to excrete ammonia, causing damaged gills and tissues, increased bacterial infections, stunted growth, and even death. The only safe level is zero. [2] [4] [5] [6]

Related guides

Sources

  1. aqueon.com: Newly set up aquariums sometimes experience dangerous spikes in ammonia and nitrite from fish waste due to a lack of the
  2. aqueon.com: Ammonia is released by fish as waste and is broken down by beneficial “nitrifying” bacteria to nitrite and then nitrate,
  3. aqueon.com: Both ammonia and nitrite are highly toxic to fish.
  4. aqueon.com: Aqueon® PURE spheres are pre-measured, ready-to-use, and cannot be overdosed.
  5. aqueon.com: When ammonia levels are high in the water they're swimming in, it makes it challenging for fish to get rid of the ammoni
  6. aqueon.com: Ammonia toxicity in fish causes them to be more susceptible to damaged gills and tissues, an increased likelihood of dev
  7. aqueon.com: The only safe ammonia level in your tank? Zero.
  8. aqueon.com: If your test strips show any levels of ammonia, stop feeding your fish because they'll produce more waste.
  9. aqueon.com: Add an Aqueon AquaPacs Ammonia Reducer to the tank after you've added new water to reduce ammonia, debris, and other wat
  10. aqueon.com: Rapid changes in pH levels can cause stress to your fishy friends.
  11. aqueon.com: Ammonia forms in your aquarium when uneaten fish food or live plants decompose in the water.
  12. aqueon.com: The nitrogen cycle is a series of events that happens after you fill your aquarium with tap or bottled water for the fir
  13. aqueon.com: It is common to notice the water gets cloudy during this cycle.
  14. wikipedia.org: The nitrogen cycle is the biogeochemical cycle by which nitrogen is converted into multiple chemical forms as it circula
  15. wikipedia.org: The conversion of nitrogen can be carried out through both biological and physical processes.
  16. wikipedia.org: Important processes in the nitrogen cycle include fixation, ammonification, nitrification, and denitrification.