Using tablet tests with the colorimeter permits detection of very low levels of environmentally significant inorganic ions, including ammonium, chlorine, nitrate, nitrite and phosphate.

Using these tests you can detect levels likely to be found in drinking water, often at concentrations less than 1 part per million (ppm). Contact us for details of how to obtain the tablets.


  • test drinking water for levels of chlorine, nitrate, nitrite, phosphate, ammonium
  • test chlorine levels in pool water
  • test the water in ponds and streams for polluting nutrients such as phosphate and nitrate
  • test soil water for nutrient levels.

Used correctly the test tablets do not pose a significant risk.

Avoid skin contact.

Phosphate tablet #1

The test for phosphate is a 2 tablet test.

Crush phosphate tablet #1 in 10cm3 of the water sample followed by phosphate tablet #2
After 10 minutes* pour 3-4cm3 into a cuvette and read absorbance using red light.

* The time needed depends on the temperature. Below 20°C a longer time may be required.

 phosphate graph