Part 1: Wavelengths of LED Grow Lights
LED grow lights are LED lights specially designed for plant growth and mainly shed red and blue light. The red light in the wavelength of about 700nm helps plants to bloom and bear fruits, while the blue light in the wavelength of about 400nm promotes plant growth.
Different plants have different demands for red and blue light. For plants whose stems and leaves are what we want, such as lettuce, we can increase the portion of blue light LED beads in the PCB design. For plants whose fruits are what we want, such as tomatoes, we can increase the portion of red light LED beads in the PCB design.
Generally, the ratio of red and blue light of LED grow lights ranges from 9:1to 6:1.
For the comfort of the eyes, a small amount of green light LED beads are also added to the PCB design.
Besides red/blue LED grow lights, there are the other type - full spectrum LED grow lights, which imitate sunshine and serve as supplemental lighting.
Compared with traditional grow lights, such as metal halide bulbs and high-pressure sodium lights, LED grow lights save the independent rectifiers and can directly power on. What's more, LED grow lights greatly save energy.