What Is The Nitrogen Cycle?
The journey from ammonia production to nitrate removal is commonly called the 'Nitrogen Cycle'
Fish produce waste products that release ammonia (NH3), a pollutant that is dangerous to your fish. Ammonia is removed from an aquarium by bacteria in your filter, which convert ammonia into nitrite (NO2)
Nitrite is also toxic to fish but another set of bacteria in your filter convert nitrite into nitrate (NO3) which is only toxic at higher levels and/or prolonged periods.
Nitrates can be removed from the aquarium through a number of means, most commonly through; water changes, plant uptake, and denitrification.
The basic nitrogen cycle is the path of nitrogen (N) through these processes:
Fish Waste >> Ammonia (NH3) >> Nitrite (NO2) >> Nitrate (NO3) >> Removal