Light Emitting Diodes
LED grow lights are composed of multiple individual light-emitting diodes.
LED’s are in reality a miniature fluorescent lamp, except that instead of using the UV and Blue light from mercury vapor to stimulate the phosphors, they use light from a blue LED chip to excite the coating on the lens.
There is no such thing as a “white” LED. Most common “White” LEDs are a hybrid system consisting of a blue LED chip with a primary lens coated with phosphors.
So in general, White LEDs are better suited for vegetation phases of growth which favor blue spectrum than for flowering, which favors red spectrum of light.
Individual LEDs usually provide only a single narrow range of color, and so different color LEDs are mixed in grow lights in proportions depending on the intended use.
White LED grow lights provide a full spectrum of light designed to mimic natural light, providing plants a balanced spectrum of red, blue and green. White LED grow lights are designed to emit similar amounts of red and blue light with the added green light to appear white to our eyes.By combining different LEDs into the lamp the light spectrum output can be customized for the particular stage of the plant growth.
The advantage of LED’s are:
Simplicity and ease of use
LEDs have no lamps to replace
Have 40-50% less cooling requirements than un-ventilated HID systems
They generate very little infra-red (IR) radiation that causes heat and can cause plant to get “leggy”.
Covers the full range of the spectrum needed by plants
Lower power consumption for PAR