Total Kjeldahl Nitrogen

What is total kjeldahl nitrogen?

Total Kjeldahl Nitrogen is a quantity measured by the Kjeldahl process, measuring the amount of nitrogen that a water sample contains in the form of ammonia and in all biological forms.

Why is TKN important?

The presence of ammonia in the water can be a cause of excessive plant growth which may prove harmful to the health of aquatic ecosystems. While ammonia in water is naturally converted to nitrate, this conversion removes oxygen from the water, which may cause an adverse impact on fish and invertebrates.

What does a measurement mean?

While it’s difficult to say what a normal Total Kjeldahl Nitrogen (TKN) value is, the higher it is, the more likely you have a problem. Typically the higher the level, the more algae blooms, the less water is clear, and the less oxygen there will be. If you see a sudden spike in this value, or have noticed more plant growth or algae blooms, it could indicate a problem with sewage treatment, agriculture, urban developments, paper plants, industrial waste, recreation, or mining (blasting residuals).

An example of a water sample to be sent for further lab testing to measure Total Kjeldahl Nitrogen
A water sample to be sent to a lab to measure for Total Kjeldahl Nitrogen

Water Rangers Protocol

We do not currently include a test for this in our kit; this is a lab test done by some of our professional partners. If you know a test that is accurate, affordable and easy-to-use, let us know!

Contributing to the community!

Water Rangers is citizen-scientist led. So, if you have any questions, ideas, or notice any errors related to conductivity, please tell us!