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 8 drops of reagent n. 1 gently swirl to mix.
3. Add a very small amount of test reagent 2, just the tip of the spatu-la, the solution turns a pink-violet colour.
4. Add one drop at a time of reagent n. 3. and gently swirl to mix the solution after every drop.
COUNT the number of drops until the solution turns from a pink-violet colour to light blue.
5.Once the solution has turned light blue leave it to stand for 30 seconds. If the colour disappears, add more drops of reagent 3 until the solution remains this light blue colour.
6. To calculate the quantity of calcium in mg/l contained in the water multiply the number of drops of reagent n.3 utilized to turn the solution a light blue colour by 20. CAUTION: it is of utmost importance that the drops of reagent n.3 are regular in size, if scarce or excessive it is recommended to repeat the test. 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.