Why are LED Grow Lights so great? 

• Use less power 

• Produce less heat 

• No noisy ballasts 

• Extremely low maintenance (50,000 hr life) 

• Produce only the light your plants need. 

Save 80% on power over HID lighting, plus reduce or eliminate power consumption by cooling systems.  

Plants can use nearly all of the light emitted from LED lamps. Only  about 10% of the power used and about 35% of 

the light generated by metal halide lamps is useful for plant growth. 

Lumens are a very common way to describe how bright a light source is.  You might see it listed on the back of a 

fluorescent light package, or a home theater projector brightness specification.  Lumens are good at telling us how 

bright something looks to a human.  Humans can see a very narrow range of the light spectrum.  Some colors appear 

brighter than others.  It’s the reason why a yellow sign looks brighter than a blue sign.  If we graph the different 

wavelengths (colors) of light, and compare them to how bright they appear, we get a graph called the luminous 

efficacy graph: 

This shows that yellow and green light appears really bright compared to red and violet light.  Lumens  

are based on this chart.  If you want to get technical, 

Luminous flux in lumens = Radiant power (watts) x 683 lumens/watt x luminous efficacy 

Now the real question that should be in your mind is “What’s good for my plant(s)?”  Here is a  graph

showing what chlorophyll uses to produce energy in your plants: 

The photosynthetic rate is what determines the energy available to a plant.  Obviously higher is better.   

Compare this graph to the sensitivity of the human eye.  It’s just about reversed!  Green, in the ~550nm  

area is very very bright to us, but worthless to a plant.  If you put a green mylar filter over your plant lights,

 you might as well throw your plants in a dark room because they will wither and die.  The reason  

plants appear green is because they reflect green light! 

This is exactly why using lumens to measure the brightness of a light “doesn’t work” with plants.  A plant  

would much rather have 10 lumens of red light than 100 lumens of green or yellow light. 

LED grow lights are the NEXT BIG revolution in indoor growing!  They consume less 

power by delivering ONLY the light your plants need, and produce much less heat.