A lumen is a measurement of the amount of light radiated by a source. Cannabis plants need at least 30.000 lumen per 3 square feet. More is better.

Learn all about growing and lighting:

More lighting related terms:

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

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

World Icon

500 Helpful Articles

200 detailed grow guides

Group Icon

35,000+ Daily Visitors

500,000+ Grow Bible readers

Plant Icon

100 Hand-Picked Strains

8,000+ connected businesses