What is a good height to hang LED grow UFO???

S

Smokenpassout

Well-Known Member
I have a grow going about 4 weeks into flower. The plant is outgrowing the confined area, and I cant get much light on top of the plant! So I thought of bringing the plant out in the open, adding a 135 watt LED UFO overhead, and CFL lighting around to finish it. My question is how high should the LED be over the top of the plant? I know the intensity of these lights can stress and burn the plant if to close.
 
This depends on the lens angle of the diodes (not often noted by manufacturers) and watts per led.

I use the hand test, or just a white envelop to see where the light just begins to lose its intensity (color) then back into it ~ 1-2 inches
 
To hang right you need about 6" between your feet and the floor.lol Put your hand under the light and see how hot it is. If it's hot on your hand it will be hot on the leaves. Some one I know put a plant under a LED after it had been under a 400 mh and the plant didn't do well. I'm not sure why that would matter. That was the only thing that changed.
 
match box said:
To hang right you need about 6" between your feet and the floor.lol Put your hand under the light and see how hot it is. If it's hot on your hand it will be hot on the leaves. Some one I know put a plant under a LED after it had been under a 400 mh and the plant didn't do well. I'm not sure why that would matter. That was the only thing that changed.
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it's got nothing to do with heat with the LEDs, it's about light intensity, too close and it will bleach/stunt growth. I keep my lights 24'' from canopy.
 
Endur0xX said:
it's got nothing to do with heat with the LEDs, it's about light intensity, too close and it will bleach/stunt growth. I keep my lights 24'' from canopy.
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Yes this is what I have heard. I just want to make sure the light isnt too close, yet not to far. My plants is mature, so it should be able to deal with a switch from cfl to led right? The purpose of the led is to get light ontop of the plant, and perhaps penetrate a bit. I still have some nice 100 actual watt 2700K cfl's to get light to the sides. So what was a good height from the top leaves of the plant? 12" 15" 18" more or less?
 
G8LED has some info out there. I have two of their 240w lights and it is recommended something like 24-36'' above the plant. I have mine at about 24'' above the pot. These were potted on 15 Dec. I started out closer until I found this info. I got some yellowing of the leaves that could be from that but I'm not sure I think the 135w is recommended to be 12-24'' awayDSC_0441.jpg
 

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Tha CHillz said:
G8LED has some info out there. I have two of their 240w lights and it is recommended something like 24-36'' above the plant. I have mine at about 24'' above the pot. These were potted on 15 Dec. I started out closer until I found this info. I got some yellowing of the leaves that could be from that but I'm not sure I think the 135w is recommended to be 12-24'' awayView attachment 2462676
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Ok well I have a much smaller light than you. A 135 watt ufo. So Im going with 12" and a few cfl's for lower foilage.
 
I'd start @ 16" above and see how it reacts.

I've never had problems with 16".... it's not too close or too far, gives you a nice starting point. From 16" you can experiment to see where your strain likes it.
 
Im 4 weeks into flower. My light is only a veg/bloom light so reds are somewhat lacking. Would 13" be too close?
 
Im 4 weeks into flowering. My light is also not a full red bloom light...more of a veg/bloom combo. With that said will 13" stress my plant. I also have 300 actual watts of 2700k cfl on the lower foilage.
 
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