There are two useful ways to monitor irrigation and fertilization. Drainage:  Drainage helps to make sure that you irrigate the right volume and that you don’t accumulate salt in your substrate, which could harm your plants. Carrying out chemical analysis of both drainage water and irrigation water at least once every two weeks will help to expose an unbalanced process. Soil moisture sensors:  These will help you to continually monitor water content in your substrate. Once you're familiar with your crop and substrate, you can adjust irrigation and fertilization schedules for optimum yield.