L.E.D plant burn??? o_O

M

mr.rollup

Member
hello, I posted a while back and I was informed that I needed much more light. I recently bought a 300 watt LED grow light for flowering. I've set it up in my closet and it was about 5 inches away from the tallest plant(that was a newb move? lol). I left the room for two mins and came back and the leaves where instantly burned : ( .. Can they recover from this? also It raised my temperature by 5-7 degrees. Is this normal?
IMG090.jpgIMG092.jpgIMG091.jpg

White Widow(fem)
hydroponic blubber 1 gal
300w LED grow light
87 degrees humidity 43
1 4inch fan venting heat up
1 2ft fan circulating air
 
edispilf

edispilf

Active Member
Hello. I am not an expert on LEDs, but I did try a 300watt in my 3X3 tent once. I think that because of the shape of the light that, if you're in a closed area, heat will build up and not be able to exhaust normally. You should just get a small fan to help move the air more and the temp should drop. About the burning...No the burnt leaves will not recover. They are burnt. I think my old LED recommended at least 18" above the canopy. It depends on the angle of light that the led lenses produce, but 12-18 should eliminate any heat burn. There is also the times when my leaves turned..almost bleached from the LED. It seems that LEDs make the plants use up Calcium and Magnesium quicker and can bleach the leaves. Use a cal/Mag suppliment or epson salts to remedy. Hope this helps.
 
jela10

jela10

Well-Known Member
When I move from floro's in veg to LED's in flower, I introduce them slowly by starting out lights-high and dropping them down some every day...the power, lens angle and spectrums are all different with each brand/type so there's a little trial and error to finding the right height. Just be conservative at first. Your temps at the display are not an issue and almost prime for LED growing (85° for my type). Get an IR gun and check the leafs nearest the panel for true temp at plant top.
 
M

mr.rollup

Member
edispilf said:
Hello. I am not an expert on LEDs, but I did try a 300watt in my 3X3 tent once. I think that because of the shape of the light that, if you're in a closed area, heat will build up and not be able to exhaust normally. You should just get a small fan to help move the air more and the temp should drop. About the burning...No the burnt leaves will not recover. They are burnt. I think my old LED recommended at least 18" above the canopy. It depends on the angle of light that the led lenses produce, but 12-18 should eliminate any heat burn. There is also the times when my leaves turned..almost bleached from the LED. It seems that LEDs make the plants use up Calcium and Magnesium quicker and can bleach the leaves. Use a cal/Mag suppliment or epson salts to remedy. Hope this helps.
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yes this helped alot thanks. I raised it a 12" I might raise a litte more, I just figured the closer the better? and as far as heat I will just keep the closet door open during the light period to help out heat. Just thought the LED lights didnt put off heat at all :/
 
M

mr.rollup

Member
jela10 said:
When I move from floro's in veg to LED's in flower, I introduce them slowly by starting out lights-high and dropping them down some every day...the power, lens angle and spectrums are all different with each brand/type so there's a little trial and error to finding the right height. Just be conservative at first. Your temps at the display are not an issue and almost prime for LED growing (85° for my type). Get an IR gun and check the leafs nearest the panel for true temp at plant top.
Click to expand...

ok cool, thank you for the response. This is my first grow so everything is trial and error, I get depressed when my babies are looking right haha
 
K

Kervork

Well-Known Member
Ambient temp has a lot to do with burning. 87 is getting a little warm. Having a fan blowing air and moving the leaves will help prevent burning also. They will recover just fine. I've dropped lights on plants and burned the fuck out of them and they recovered.
 
K

Kervork

Well-Known Member
In fact, they're looking a little spindly so the heat induced topping might just be the best thing that could happen to them.
 
M

mr.rollup

Member
Kervork said:
In fact, they're looking a little spindly so the heat induced topping might just be the best thing that could happen to them.
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Can you paraphrase? I'm sorry I don't understand what you mean lol. Initially I started out using 15w cfls and I was told thats why the were lanky? so I bought this LED for more light
 
edispilf

edispilf

Active Member
If you're still in veg, snip the tops and let them bush, if you're in flower and don't want to delay that, then I'd just remove the burnt leaves. Don't snip them down too far, just the tops. If you're not sure, hit youtube or whatever and watch someone do it first. Generally referred to as topping or other variants such as LST, SCROG, and FIM technique.
 
Jimdamick

Jimdamick

Well-Known Member
This is a plant that got to close to the LED, and it was bleached white, with the top of the cola being scorched. It happened 3 weeks into bloom, and this is what it looked like when it was finished 8 weeks later. Believe it or not it was pretty tasty.DSCF2350.jpg
 
edispilf

edispilf

Active Member
oops sorry for the late reply....Since you're in flower, I wouldn't top. Just remove the dead leaves and let em go. Just my humble opinion.
 
M

mr.rollup

Member
edispilf said:
If you're still in veg, snip the tops and let them bush, if you're in flower and don't want to delay that, then I'd just remove the burnt leaves. Don't snip them down too far, just the tops. If you're not sure, hit youtube or whatever and watch someone do it first. Generally referred to as topping or other variants such as LST, SCROG, and FIM technique.
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ok cool, will check that out
 
edispilf

edispilf

Active Member
You will get a lot less stretch, because of the LED's over the CFLs you were using. That and that you're 2 1/2 weeks in is why I wouldn't top these
 
M

mr.rollup

Member
8weeks!? that looks intimidating to my plants : ( lol...that looks sweet though! hope mine turns out decent for my first grow!
 
edispilf

edispilf

Active Member
If you let these go, next time while they are vegging, you should top them to produce more branches/shorter, bushier plants = more flowering tops....Hang in there you're doing good for a first grow....it's a never ending learning adventure....just when you think you know it all, you figure out that you don't and then you feel that way again :) Ride the wave
 
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