Grow lights very high above plants

[Stunned]

Aurora Corp which produces HUGE quantities of Cannabis for medicinal and recreational use
I'v seen pics of their grow op, and they're the size of multiple football fields
Their lighting is way up high, at least 8 feet above the plants

 

[Medkit1620]

The idea as to why LARGE grow opps do this is because when working with any grow light LED, HPS, HID, ect. the biggest problem is that it dose not have the same light penetration as natural sunlight. This is caused by the inverse square law so you will see a sharp drop off in bud size the lower down in the plant. By having multiple lights you can increase the light penetration but it would burn the tops of the plants if it were 24" above the plants so it is necessary to raise it up.

This is not very useful for small scale operations because of space restrictions and similar result are achievable with training techniques. However for large operations training means added labor cost and possible human error and it is much harder to standardize.

In short I wouldn't worry about it to much. LED's are getting better at light penetration but, there is growing suspicion that the green spectrum plays a role in light penetration. So I say get full spectrum lights. Adding reds and playing with your light spectrum is pretty advanced stuff so I wouldn't think about that yet.

 

[Growingasmile]

"How do people get away with having their lights so far above their plants? "

Far enough away so you dont get too much radiant heat load onto the plants and crisp them.

You just need a fan with cool ac air i put my 1000w hps just 2 feet above my plants

 

[kingkola1]

I have a 1000 W MH bulb for veg and a 1000 W HPS bulb for flower. I raise the light to maintain roughly 40,000 lux for veg and 65,000 lux for flower. Which is about 24" above the canopy plus or minus. 15,000 - 50,000 lux - good amount of light for healthy vegetative growth; so 40,000Lux is a good starting point...45,000 - 70,000 lux - optimal amount of light for cannabis plants in the flowering (budding) stage; so 65,000 Lux is a good starting point. Adjusting the distance above the canopy as needed a few inches based on how the plant is reacting. I don't think you can use a light lux meter with LED lights though. I agree with those above, if the distance above the canopy is significantly higher than the norm in the video and the plants look healthy then it was probably moved up for making the video.