Its a process that occurs in all home aquaria and is the cycle of converting ammonia, which is produced by fish waste and decomposing organic matter, into nitrite and then nitrate, which are less toxic to fish. The cycle involves beneficial bacteria that colonize the filter media and the substrate of the aquarium. The nitrogen cycle is important for keeping tropical fish healthy and preventing ammonia poisoning, which can cause stress, disease, and death.
You need to add a source of ammonia to the aquarium to start the process, such as fish food, pure ammonia, or a few hardy fish. You need to monitor the water to keep the ammonia and nitrite levels below 0.5 ppm.
The nitrogen cycle can take several weeks to complete, depending on the size of the aquarium, the amount of ammonia, the temperature, the pH, and the oxygen level. Live plants, filter media, or gravel from an established aquarium, or by using commercial products that contain beneficial bacteria can help to speed up the process.
Once the nitrogen cycle is established, you need to maintain the balance, by avoiding overfeeding, overstocking, or overcleaning the aquarium. You also need to replace the filter media regularly, but not all at once, to avoid disrupting the bacterial balance. You should keep the nitrate level below 40 ppm by performing regular partial water changes.
