Nitrite is toxic and should be undetectable in any well established aquarium. During cycling, it may exceed 20 mg/L. Nitrate is relatively non-toxic, but it is advantageous to control it to under 20 mg/L.
MultiTest™ Nitrite/Nitrate measures nitrite to less than 0.1 mg/L and nitrate to less than 0.2 mg/L in marine or freshwater. The values reported by this kit are expressed as nitrite and nitrate rather than nitrogen (to convert to nitrogen, simply divide by 3.3 and 4.4, respectively). It performs over 75 tests and contains a reference sample for validation.
MultiTest™ Nitrite & Nitrate performs over 75 tests
And with the multi-cavity test plate, multiple tests can be run at the same time.
It isn’t necessary to run a reference test to use this kit; however, its proper performance can be validated by running a test in the normal manner except that the reference sample is used in place of aquarium sample. You might choose to run a reference test if you have cause to believe the test is giving incorrect results.