Luster Leaf Rapitest Soil Test Kit, 40 Tests: * Innovative and inexpensive soil test kit features an easy-to-use capsule system and color comparators * Contains tests for ph, nitrogen, phosphorus and potassium levels with 40 tests in total * Also has a chart of pH and NPK levels for more than 100 plants * Simple, fast, and accurate results: no experience required to perform tests * Includes complete instructions for adjusting soil conditions