Marijuana has been cultivated for centuries by cultures throughout the world. Some cultures use marijuana in religious ceremonies, others use it to relieve to medical ailments, and some use it for recreational purposes. The first indoor marijuana growers relied on High Pressure Sodium (HPS) and Metal Halide (MH) grow lights as a sunlight replacement for plants indoors. These forms of High Intensity Discharge (HID) lights produce a full-spectrum white light, the final color of which is determined by the gasses and elements within the bulb. While these full-spectrum HID lights have worked well to grow marijuana for decades, the majority of light they create is unused (reflected) by plants. In fact as much as 70% of the light they create is never processed during photosynthesis, meaning the majority of the power they consume is simply wasted energy.
Marijuana has evolved over thousands of years to process certain wavelengths (colors) of light that the sun provides, while reflecting most others. The wavelengths it processes for photosynthesis are 439nm and 469nm blue, and 642nm and 670nm red, which are converted by Chlorophyll A and B. HID Grow Lights emit low amounts of light at these wavelengths, focusing the majority of their output in the 500-600nm region (outside of the photosynthesis wavelengths). It is for this reason that HID Grow Lights are quickly being replaced by LED Grow Lights, as LED's are able to focus their spectrum on the wavelengths plants use most efficiently.
LED Grow Lights
LED Grow Lights are comprised of multiple low-wattage diodes (normally 1W-5W) that work together to create the complex spectral varieties that marijuana requires to grow properly. LED Grow Lights work almost like a puzzle, with each LED wavelength playing a specific role in determining how the plant will grow and produce. By fine-tuning the wavelengths and ratios of a LED Grow Light properly, up to 100% of the light being produced can be efficiently absorbed marijuana plants. This gives LED Grow Lights a huge efficiency advantage over HID Grow Lights, allowing the end user to consume far less energy to achieve similar or better results.
LED Grow Lights provide many additional benefits that HID lights do not. LED Grow lights contain no mercury or harmful elements, and as such can be fully-recycled. HID bulbs on the other hand, must be changed at least once per year at a cost of $100-$200! LED Grow Lights also consume about 60-70% less energy, putting money back into your pocket with each power bill. LED Grow Lights also operate up to 600 degrees colder than HID Grow Lights, virtually eliminating the need for ventilation and A/C equipment.