Tropic Marin NO2/NO3 Test Professional for high precision determination of the nitrite and nitrate concentration in freshwater and seawater. Nitrate ions (NO3-) are formed from ammonium (NH4+) as the end product of the nitrification process. Nitrite (NO2-), which is highly toxic to freshwater species in particular, is produced in the first stage of the bacterial process. If the nitrification process works, nitrite is converted to the comparatively non-toxic nitrate in the second stage. Increased levels of nitrite above 0.05 mg/l (ppm) are usually found in tanks that are in their maturation phase or in tanks with nitrate filters.Nitrate affects the quality of the water in the aquarium: Higher concentrations of nitrate in saltwater aquariums will end up inhibiting the growth of delicate coral. An algal bloom is often the result of a high nitrate level in an aquarium. Some reef aquariums have ultra-low nutrient conditions - nitrate shortages can occur in cases such as these. Therefore, th