This kit measures nitrite to less than 0.1 mg/L and nitrate to less than 0.2 mg/L in marine or freshwater. MultiTest™ Nitrite. Nitrate performs over 75 tests and contains a reference sample for validation. Range: NO2 : 0-25 mg/L, NO3 : 0–50 mg/L. Precision: NO2/NO3 : 0.1–1 mg/L
A: The test well you are using may be contaminated with Nitrate Reagent#2. Soak the test well sheet in vinegar overnight, then rinse thoroughly with tap water, followed by DI water, and dry completely.
A: If you are getting a pronounced nitrite reading, it is not possible to get an accurate nitrate reading, since the nitrite reading will interfere. You should be able to make a very approximate assessment of nitrate, since the nitrate color will be additive to the nitrite color.
A: Unfortunately, there is not a test kit on the market that can distinguish between the bound form of nitrites/nitrates in the presence of Prime and the unbound form without Prime. As long as you have dosed the correct amount of Prime to your aquarium, you can rest assured that the nitrites and nitrates are safely detoxified.
A: There was an unfortunate typo on several batches of the Nitrate instructions in which the reference was listed as 1 mg/L; it is actually 10 mg/L (which actually makes your problem even more pronounced!). However, if you do the two following two things your test should read the reference correctly (a) use 2 full stems of sample instead of 1 and (b) vigorously shake, squeeze and tap on a table the Nitrate Reagent#2 so that you obtain a very distinctly grey drop. Assuming you get a correct reading with the reference, you can now run your test samples in the same manner and be assured of the test's accuracy. If have followed the above instructions yet you still get too low a reading for the reference, then contact us to obtain replacement reagents.