For those who always say, your lights are to close.

shawnery

shawnery

Well-Known Member
I'm always hearing, your lights are to close, when people post photos with plant issues. It often seems like one of the first mentioned issues besides the obvious ones. I don't only here this in response to hps or mh but LEDs as well. I just this this info when it comes to LEDs is just so outdated. LEDs don't let off as much heat and they create less leaf surface temperatures because of no IR which increases internal leaf temps.

Here's a photo of my current crop which is never further than 18" away but considering my scheduale has got as close as 9". The photo below is 11" with absolutely no signs of leaf damage from my lights at all at full power giving off 1640 watts.

My point only is that I think when it comes to LEDs that this understanding of light distance needs to change when it comes to LEDs or are my top notch LEDs special, I think not.
 

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FlyHigh589

FlyHigh589

Well-Known Member
Also realize that many strains are very different in how they can take light. I have had 2 phenotypes of the same strain: one was happy as hell being 12 inches away from my Cree Cobs with the other vastly preferring to be kept 22-26 inches from the same lights.

With growing, there is often not just 1 possible correct answer to issues, and while often times it may be given as incorrect advice, but at the same time, you can’t really say that all strains perform identically the same distance from the lights.
 
Kushash

Kushash

Well-Known Member
shawnery said:
I'm always hearing, your lights are to close, when people post photos with plant issues. It often seems like one of the first mentioned issues besides the obvious ones. I don't only here this in response to hps or mh but LEDs as well. I just this this info when it comes to LEDs is just so outdated. LEDs don't let off as much heat and they create less leaf surface temperatures because of no IR which increases internal leaf temps.

Here's a photo of my current crop which is never further than 18" away but considering my scheduale has got as close as 9". The photo below is 11" with absolutely no signs of leaf damage from my lights at all at full power giving off 1640 watts.

My point only is that I think when it comes to LEDs that this understanding of light distance needs to change when it comes to LEDs or are my top notch LEDs special, I think not.
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It's not easy helping newbies.
They usually have a host of problems and often they don't fill in all the blanks.

You can get away with keeping your light closer because your grow is dialed in.

A new grower won't be able to keep it as close as their environment, medium and grow skill will cause more problems when the light is as close as you can keep it.​
 
Thundercat

Thundercat

Well-Known Member
Well I'm glad I'm not the only one that believes in using the light I pay to run instead of lighting up the walls. I'm all about keeping my lights as close as possible. In veg my t5s literally are less then 2 inches from my plants. My 1k hps is typically 12-14 inches from my canopy, it would probably always be 12ish inches but sometimes my plants are different heights since I run multiple strains in the same tray.

Inverse Square Law- http://lmgtfy.com/?q=inverse+square+law+of+lighting
 
myke

myke

Well-Known Member
Ive always just used my IR therometer,I keep my leaf temp same as room temp.If it goes up i lift the light.
 
Thundercat

Thundercat

Well-Known Member
mastrmasn said:
Had my LED build as close as 2” from top of buds last run. Never had an issue. Big beautiful rock hard nuggets.
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See that makes plenty of sense to me.

I've never ran LED, but I regularly see people talking about 20+ inches from the plants and it seems like that would waste so much of the light.

Obviously there is a point where plants can get bleached but I've only seen it a few times over the years. When it has happened to me it was because my closest tops were in the 8-10 inch range from a 1000w bulb.
 
mastrmasn

mastrmasn

Well-Known Member
Thundercat said:
See that makes plenty of sense to me.

I've never ran LED, but I regularly see people talking about 20+ inches from the plants and it seems like that would waste so much of the light.

Obviously there is a point where plants can get bleached but I've only seen it a few times over the years. When it has happened to me it was because my closest tops were in the 8-10 inch range from a 1000w bulb.
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Haven’t ran HPS in 20 years. Seems to me we kept it 24” sometimes even closer never remember having bleaching.
 
StareCase

StareCase

Well-Known Member
In the past couple of days, I have also been reading a few article from other folks s who are saying that 12" - 14" is far enough away, even with some of the more powerful LED panels. I kept mine about 20" - 22" above for this grow but if 12 - 14 is far enough, I would lower them and get another 6" - 10" of light penetration into the canopy.
 
Chemically altered

Chemically altered

Well-Known Member
D816AAEC-205F-4F5F-ABDD-85B8DBBF3CAA.jpeg
shawnery said:
I'm always hearing, your lights are to close, when people post photos with plant issues. It often seems like one of the first mentioned issues besides the obvious ones. I don't only here this in response to hps or mh but LEDs as well. I just this this info when it comes to LEDs is just so outdated. LEDs don't let off as much heat and they create less leaf surface temperatures because of no IR which increases internal leaf temps.

Here's a photo of my current crop which is never further than 18" away but considering my scheduale has got as close as 9". The photo below is 11" with absolutely no signs of leaf damage from my lights at all at full power giving off 1640 watts.

My point only is that I think when it comes to LEDs that this understanding of light distance needs to change when it comes to LEDs or are my top notch LEDs special, I think not.
Click to expand...
I think your right about light height. This is my first grow and I’ve had the lights at 11 inches a lot of times and my plants look fine to me?
 
shawnery

shawnery

Well-Known Member
It's the dance between penetration and coverage with lighting. I need atleast 10" to get the coverage I need but agree you can get closer and have during flowering.
 
C

churchhaze

Well-Known Member
I keep my vero 18 C build (700mA) around 4-5 inches away because I always run out of space. Sometimes they touch become charred, but that's only if it touches.

I can easily see how even bigger cobs would be fine at 12" as long as there's no optics.
 
Thundercat

Thundercat

Well-Known Member
I really bet 5-6" is enough with most LEDs out there. They are not putting out that much heat or focused intensity. I'm sure spread is the biggest reason to raise them some, but I'd hate to waste light by raising them much. I'd rather add more lights to get the coverage needed.

I gotta think having the lights so high is probably one reason people don't get the results they want from some LEDS.
 
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