DLI is equally as important indoors as it is in an outdoor/greenhouse environment and should be utilized when trying to optimize your grow efficiency and overall plant health. DLI stands for ‘Daily Light Integral’ and is defined as a measure of usable light your plant receives over the course of a day. Too high of DLI will not only cause unwanted light stress/burn but it is also a waste of electricity for which you are paying. DLI numbers that are too low will limit your plant’s growth potential which can translate directly to reduced yield and plant vigor. In either scenario, not measuring your DLI and tailoring your light intensity/schedule will end up costing you. Before we dive into how to accurately measure DLI, lets cover the basics on lighting.