Salifert NO3 Nitrate test
Nitrate testing: When an aquarium has insufficient regions deprived of oxygen (= anaerobic zones) or denitrification proceeds incompletely then nitrate will build-up. A too high nitrate concentration can result in unwanted algae-growth and these might irritate corals in their neighborhood. Nitrate as such also retards coral growth. The nitrate concentration in a proper functioning reef aquarium should preferably be lower than 1 mg/L. Fish-only aquariums would usually show much higher nitrate concentrations.
Most test kits use a procedure in which a certain part of nitrate is converted chemically into nitrite and is measured as such. Once again, just as with nitrite testing, amine interference has a major impact on the measured value. If such an interference occurs concentrations much lower than actual will be measured.