The Best Grow Lights - Fluorescent vs. LED
Engineering and Design
Fluorescent lamps work by passing electricity through a gas-filled tube that contains mercury. When the mercury atoms are excited by electrical current, they give off ultraviolet light, which is invisible to the human eye. The UV light reacts with phosphors coating the inside of the tube, causing them to give off light in the visible spectrum. The type of phosphors in the coating determine the colors of light given off, although somewhat imprecisely. The mercury and other compounds in fluorescent lamps are toxic and need to be handled with care against exposure and add toxic waste to the environment.
LEDs (light-emitting diodes) produce light by running electricity through a very small, solid semiconductor that glows in a very specific wavelength. Full-spectrum LED grow lights use an array of diodes to shine light of different wavelengths in a specific combination to produce the colors desired for optimum plant growth and yield.