A nanometer is a metric system unit that equals a billionth of a meter. Nanometer (nm) is also used to describe the wavelength of light.

• Red light has a wavelength of 650 nm
• Blue light has a wavelength of 450 nm

Learn all about growing and lighting:

• The Cannabis Light Cycle
• Control Your Lighting, Control Your Cannabis
• How Much Sunlight For Outdoor Marijuana Plants

More lighting related terms:

Lighting | Light cycle | Dark cycle | Light shortage | Light distribution | Light spectrum | Blue light | Red light | Light tight | Lumen | Lux | Reflecting light | Lamp height

HPS lights | HPI lights | LED lights | Compact fluorescent lights