What is ammonia NH3 & NH4?

Ammonia is passed from the gills of fish in their urine and rotting food or decaying plant matter are contributors of ammonia.

It exists in two forms in the aquarium and the first step is to understand the difference between ammonium NH4 and free ammonia NH3.
 

NH3 (ammonia) is a gas and sometimes called toxic or free ammonia. This is the type of ammonia is the dangerous part.

NH4 (ammonium) is a nontoxic salt it is the ionised form of ammonia.

NH3 and NH4 together are often refered to as total ammonia nitrogen (TAN). 

The seneye device measures NH3 directly between 0.001ppm and 0.500ppm. The range that seneye can detect NH3 is below the toxic level, allowing you to take corrective action to an increased level before it becomes toxic.

Traditional liquid Ammonia test kits mostly measure TAN especially if they are marked as an NH3/NH4 or NH3-N. For more information on what they are reading, and why it isn't comparable with the NH3 output from seneye is avalible here.

Why does my free ammonia NH3 go up when I do water changes click here?

If your ammonia is very high you may find it useful to learn how to control ammonia.


Can my seneye be used for cycling my aquarium?