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 a small amount of the test reagent n. 3 (powder), just the spatula and swirl to mix. Powder does not dissolve completely: for better colour comparison, hold the test jar at an angle until the remaining powder collects on the side.
4. 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.
5. 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: if the quantity of nitrates in the water exceeds 25 mg/l, it is of utmost importance to change a small amount of the water and to 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.