Better understanding of cannabis-related photobiology is helping LED grow light manufacturers produce lighting that increases crop yields and perhaps more importantly, cannabis quality. For the last 50+ years, indoor cannabis cultivators have used High Pressure Sodium (HPS) lights to illuminate their flowering crops. This technology was developed for, and is still used, as street lighting and there really hasn’t been a fundamental change to the output in the last half century.LED technology showed great promise to solve some of the primary drawbacks to the use of HPS technology for indoor cannabis cultivation.  We are often asked why this technology was used to grow cannabis, and the answers are simple: 1) due to strict legislation and even stricter penalties for growing cannabis, growers wished to move their crops indoors, and, 2) there really hasn’t been another technology that would allow us to cheaply place 400, 600, or even 1000W of light on a crop. In addition, HPS technology is rich in certain frequencies of red light, which is so important to flowering crops. Unfortunately, HPS lamps have their drawbacks, such as high heat output and lack of other “colors,” along the lig...