Salifert Profi Test Kits for reef, marine and advanced freshwater aquarists are some of the most precise and accurate test kits on the market. Kits are available for all aspects of the aquarium’s chemistry, covering organic and inorganic pollutants as well as valuable marine trace elements to allow for accurate dosing when additives are required. The kits feature bold colour changes and good colour comparison charts and offer quick and easy water testing. There are 16 kits in the range, and most are suitable for both freshwater and saltwater environments (unless otherwise stated). Nitrite Profi-Test: * In a properly cycled aquarium, nitrite is converted to nitrate and then, if there are areas deprived of oxygen such as in live rock and other filter materials, this nitrate is converted back to nitrite and then transformed into harmless nitrogen gas. * If this cycle breaks down then nitrites, which are extremely toxic to fish and invertebrates, can form in high concentration. * Many nitrite test kits suffer from interference caused by amines e.g. naturally occurring and essential amino acids. This can result in a too low measured value, especially when the nitrite concentration is relatively low. * Because of its unique formulation, the Salifert Test Kit does not suffer from amine interference, and offers full colour development within one minute. Also, the colour is very intense making the detection of even minute traces of nitrite easy. * The test kit has two different scales: an ultra-low scale for nitrite-nitrogen which ranges from 0.002 – 0.12 mg/L, and a medium scale for nitrite-nitrogen which ranges from 0.02 – 1.2 mg/L. * Sufficient for 50 tests.