The Viagrow broad range pH indicator test kit gives you an accurate idea of your pH value. The Drops are reliable and simple to use. 1. Fill the test tube with 5ML of sample water or nutrient solution to be tested. 2. Add 5 drops of the pH solution. 3. Swirl gently and compare the color of the solution to the color of the chart which will indicate your pH value. Red (acidic) indicates that the pH is too low, blue (alkaline) indicates that the pH is too high, a yellow to a yellow-green indicates an ideal pH. Comes with an easy to match pH color chart and can test up to 160 samples or uses. Unlike other pH test kits the Viagrow pH test kit can test a broad pH range from 4. 0 to 10. 0.