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.

Ammonia test kits mostly measure TAN especially if they are marked as an NH3/NH4 test kit. The measurement is done by changing the pH of the water sample; you may have noticed how ammonia test kits normally have a small bottle marked harmfull corrosive. Using NH4, temperature and pH to accuratly work out how much NH3 is present is very very difficult click here to find out why.

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?