Ammonia (NH3)

What is Ammonia?

Ammonia is introduced into your aquarium via fish respiration, fish urine/waste, and decaying matter (uneaten fish food, dead leaves, dead fish, dead bio-cultures...). In a healthy aquarium, there should really be no measurable trace of ammonia as your established biological filtration system will readily convert any ammonia to firstly nitrite, then nitrate. (see cycling for more information)

Ammonia is extremely toxic to fish and is commonly present in new tanks, undergoing the cycling process (establishment of a nitrosomonas bacteria colony). Since a nitryifying bacteria colony has yet to develop in a new tank, the ammonia accumulates within the aquarium causing severe and often irreparable damage to fish during this process; hence, the "new tank syndrome".

Measures can be taken to minimize the harm to fish during this cycling process:

  • fishless cylcing through the use of pure ammonia
  • seeding aquarium with gravel and/or filter media from established aquariums
  • transfer of filter from an established aquarium
  • close monitoring of water parameters and frequent initial water changes

Testing for ammonia should be done frequently in a new tank setup (as often as twice daily, coupled with water changes, if ammonia readings are dangerously high). In an established aquarium, ammonia testing can be done on a weekly or bi-weekly basis, depending upon the experience of the aquariast and the age of the aquarium. A sudden rise in ammonia levels, should be a cause for alarm (possible dead fish, power outtage, filter problems, overstocking, bacteria colony dying...)

Test kits for ammonia often measure for both ammonia (NH3) and ammonium (NH4). Ammonium is far less toxic than ammonia. Ammonia can readily change to ammonium and vice-versa within the aquarium. Factors which affect the levels of ammonia and ammonium are PH and temperature. High PH values fosters the more harmful form of ammonia, while lower PH values favours the less harmful form of ammonium. Likewise, higher temperatures favour ammonia and lower temperatures favour ammonium.

Optimum level of ammonia: 0 ppm
Removal: Biological Filtration (Nitrifying bacteria conversion to Nitrite), Water Changes