1. Rinse the water sample test tube several times with the water to be tested and then fill with sample water to the 5 ml mark.
2. Add 4 drops of reagent n. 1 and swirl to mix.
3. Add 4 drops of reagent n. 2 and mix by repeatedly turning the test tube upside down, the water changes colour. Development time is approximately 4 minutes.
4.Match the colour of the sample with the colour chart by positioning the test tube next the most similar colour. For accurate readings compare the colours from above. CAUTION: in the event the nitrite concentration exceeds 0,5 mg/l it is necessary to regularly change a small quantity of the aquarium water and use a specific product such as PRODAC’S NITRIDAC. Thoroughly clean the test tube after use, securely seal all reagent containers and store in a cool, dry place away from sunlight. Keep the product out of reach of children.