Seachem MultiTest - Nitrite & NitrateMultiTest Nitrite Nitrate Measures nitrite to less than 0. 1 mg L and nitrate to less than 0. 2 mg L Multi cavity plate for simultaneous testing of up to 6 tests at the same time Includes reference for test validation Marine or freshwater 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