Product: Nitrate Test kit
When there are insufficient areas of a tank which are deprived of oxygen (anaerobic zones) or denitrification is not taking place properly, nitrate will build up. This can also happen in an aquarium where the biological loading on the system is causing an imbalance e.g. if there is excessive livestock for the aquarium volume or over feeding is occurring.

The build up of nitrate can result in unwanted algae growth and the slowing down of coral growth.

The nitrate concentration in a reef aquarium should be lower than 1 mg/L, although fish only aquariums would usually have a higher concentration.
Just as with nitrite, many nitrate test kits are prone to amine interference which can make the levels of nitrate appear much lower than they actually are.
The Salifert test kit does not suffer from such interference and gives accurate and quick results with a total testing time of less than 3 minutes.
The test kit’s range goes from a very low to a very high nitrate concentration (approx. 0.2 - 100 mg/L as total nitrate).

Instructions:

• Low range: 0.2 - 10 mg/L (ppm) as nitrate.
• Medium range: 2 - 100 mg/L (ppm) as nitrate.

Procedure for both ranges:

• Fill test vial with 1mL of water.
• Add 1 level scoop of NO3-1 powder (compress this powder against the inner side of the powder container).
• Add 1 level scoop of NO3-2 powder and swirl gently (do NOT shake) for 30 seconds.
  Let it stand for 3 minutes.

Color comparison:

• Medium Range - Place the test vial on the white part of the color chart and compare colors looking from the TOP. Use diffuse daylight when comparing colors. If the color corresponds to a value lower than 10mg/L nitrate then it might be better to compare colors as shown for the low range (see below).

• Low Range: - If the medium range color comparison procedure gave a reading lower than 10mg/L then you can use the low range prodecure. This will increase the accuracy. The color for the low range procedure has to be compared by looking through the SIDE of the test vial. The white part of the color chart has to be held firmly against the opposite side of the test vial. Use diffuse daylight when comparing colors. The color is, by looking through the side, amplified by approximately 10 fold. For this reason you have to divide the color chart values by 10. For example 2 will become 0.2 and 50 will become 5.

Note:
Keep out of the reach of children! Only for aquarium hobby use.
The use of protective gloves and eye protection is recommended.
Please read the instructions carefully before using the product. 

The KH/Alkalinity reageant contains a dye. Avoid spilling the dye on fabric and other materials since they may become stained. Keep out of reach of children. Not for consumption.

Salifert:
Salifert is a Netherlands base company that produces top of the line test kits as well as tank additives and foods for marine and reef aquariums.
Salifert is well established and popular with hobbyist for their accurate and affordable test kits.