Perform qualitative soil tests without the use of chemical reagents and test tubes. This kit lets students use a simple three-step process involving water, tablets and color comparators. To test soil, simply mix it with water and let it settle. Then pour the liquid off into the color comparator, add a tablet and compare the liquid with the color film chart for a test reading. Includes (10) tests each for pH, nitrogen, phosphorus and potash and full instructions.