LED grow light question.

ive been getting some mixed answers about how much square feet does a 90w UFO LED grow light cover, so does any one know for sure?

thanks,
avi

 

Quoted from this website: http://www.ledgrowlightsoutlet.com/90-w-ufo-led-grow-lights.html

"# Coverage: Each light covers 1-4 square meters of growing space (when set .3-.6 meters away from plant)
# 120 degree beam angle covers 40-80 square meters of growing area (when set 2-3 m. above plant)"

 

It depends on the height of the light.
Let's say the cover area is a circle
If you put the light 1 m height, the diameter of the cover area is 2m.
If you put it 0.5 m height, the diameter is 1m.
Generally we put it 1.5m height, it depends.