Marine Multi-Test comprises everything you need to carry out 155 tests (combined) of the 4 key water parameters to keeping a healthy marine aquarium: ammonia, nitrite, nitrate & pH. All tests use liquid reagents for improved accuracy. Full instructions are included detailing optimum levels and suggestions for correction, along with an integrated test tube rack. Simply follow the easy-to-read pictorial instructions and compare the test tube to the colour chart. Complete with 4 test tubes and a set of colour coded stickers to allow you to label both the test tubes and lids to ensure the same test is always carried out in the same test tube to avoid contamination. This test kit reports concentration in terms of nitrogen (NH3-N), (NO2-N) or (NO3-N) to be compatible with reported safe concentrations as they apply to fish and plants. If you are interested in knowing the ionic concentration of the measured parameter, multiply your result by 1.21 (NH3-N), 3.29 (NO2-N), or 4.43 (NO3-N).