Its vital to know the existing pH Nitrogen N Phosphorous P and Potash K levels in garden soil. The rapitest Soil Tester continues to be a great value for home soil testing. The kit includes all components needed to for 10 tests: 4 each for pH 2 each for Nitrogen Phosphorus and Potash. The color coded test tubes are included and allow for color comparison against the color chart also included. Extensive yet simple instructions are included along with recommendations for over 25 plants. Test results allow the gardener the amend and fertilize appropriately ensuring the best possible results.