Digitally test your soil with ease. Soil tests are performed in four separate color-coded tubes: green for testing pH, purple for Nitrogen, blue for Phosphorus, and orange for Potash. Capsules for each test are color-coded to match the corresponding tube’s cap. When testing, use the dropper to transfer the test solution into the test tubes, and the optical calibration system will recognize the hue specific to your soil’s pH and nutrient levels to provide results. Test Kit also contains a handy test tube-holder to secure all four tubes during testing while the color develops. Performs 25 tests: 10 for pH, 5 for Nitrogen, 5 for Phosphorus, and 5 for Potash. Includes test tubes, test capsules, dropper, and instruction booklet — complete with guidelines on how to fertilize and amend soil based on results.