The easier than ever way to help gardeners grow greener lawns, abundant flowers, fruits and vegetables. This revolutionary kit takes the guesswork out of determining whether your soil pH needs adjusting or nitrogen, phosphorus and potash should be added in the form of fertilizers. Just mix soil and water together, pour off solution into comparator, add one tablet, shake and compare to color chart. It's just that easy. Contains supplies for 40 tests - 10 each for pH, nitrogen, phosphorus and potash.