The Salifert Nitrate Test Kit measures the extremely hazardous nitrate levels that build up in spaces which have been deprived of oxygen. High nitrate levels can lead to undesirable algae-growth and coral damage. The ideal nitrate concentration in a healthy reef system should be lower than 1 mg/L, but fish based aquariums may show drastically higher concentrations. Additionally, the unit is able to detect both small and large concentrations of nitrates. Unlike other nitrate testers, the Salifert Nitrate Test Kit is not impacted by the presence of amines. Contains ingredients that provide accurate and immediate readings.