Today, more and more growers are opting out of traditional HID and T5 fluorescent lights, and installing LED lighting instead. Compared to HID light sources, leds emit less heat, which means that LED planting lights are not as close to the tree canopy as traditional planting lights. https://www.phlizonstore.com/blogs/knowledge-center/how-far-should-led-grow-lights-be-from-plants-at-different-growing-stages