# Please explain the phrase "Penetration" in reference to lights.



## POTUS

I keep running into the phrase "Penetration" in reference to the use of lights on an indoor grow. Statements like "Provides better penetration" and "Not enough penetration".

Scenario: A grow room that is covered wall to wall with plants. The leaf canopy of plants is in excellent health and has no openings in it as viewed from the top.

I'd like to hear everyone's take on exactly what this means to them if applied to the above scenario.

1. What is "Penetration"?

2. Why is penetration needed?

3. What happens if penetration is not present?

Please answer these questions specifically in reference to the scenario as stated above.

To be fair, I have to make it clear that I believe "Penetration" to be another fallacy in the minds of over-enthusiastic growers that have picked up a trade phrase that is inappropriately used and has no real merit.

Anyone who can provide me with ANY professional reference to Light Penetration that specifically means beneficial light reaching through a plants leaf canopy to the lower leaves of the same plant and providing something NOT gained by the upper leaf canopy, please do so. I'm betting that no one can. Please don't swamp me with anecdotal stories.

I would be especially interested in any comments on the benefit of actually *removing* leaves to allow "penetration" to the lower areas of the same plant.

Please keep in mind that I am NOT trying to start an argument. I'm trying to bring a misconception to light and explain to everyone how this fiction of "Light Penetration" is a well spread myth that holds no true scientific basis or benefit.

In actuality, I would love it if someone proved me wrong with quotes from anyone who is a plant biologist or other professional in the field. Please link to any articles or studies that show me being incorrect.

Thanks,

Stoney


----------



## Puffin Afatty

:farm: When I refer to light penetration, I mean the distance the light remains effective during flowering

With a 400w hps lamp, the effective radius is 22 inches from the lamp in all directions, 33 inches with a 600w and 53 inches with a 1000w etc. it's an energy thing.  

any buds beyond the radius will not get enough light 

as far as the canopy coverage, in my experience, I see that it does help to get light to any part you want to grow, within the effective radius however, I dont believe in removing leaves to accomplish this, I prefer a lst, scrog or other bending style :hubba:


----------



## The New Girl

POTUS said:
			
		

> I'd like to hear everyone's take on exactly what this means to them if applied to the above scenario.
> 
> 1. What is "Penetration"?
> 
> 2. Why is penetration needed?
> 
> 3. What happens if penetration is not present?
> 
> 
> Stoney



1. I think I know 
2. For satisfaction usually
3. Definitely no babies.

  Hi POTUS -
  I hear that and think the light isn't getting through to the lower buds/leaves cause it's being blocked by the upper ones, probably wrong on my thinking but that's what i get, not penetrating to the bottom because it's blocked...(i don't mean going through the leaf like x-rays)


----------



## POTUS

The New Girl said:
			
		

> 1. I think I know
> 2. For satisfaction usually
> 3. Definitely no babies.
> 
> Hi POTUS -
> I hear that and think the light isn't getting through to the lower buds/leaves cause it's being blocked by the upper ones, probably wrong on my thinking but that's what i get, not penetrating to the bottom because it's blocked...(i don't mean going through the leaf like x-rays)


Ref: 2. For satisfaction usually
Call me: 1-555-444-1212 HAHAHAAHA 

The light that contacts any leaves on the plant benefits the entire plant, not just the part that the light hits. Having it hit somewhere else on the plant is pointless. The plant will create additional leaves to gather sunlight until it's maxed out or as close as possible. Removing leaves to let sunlight through to other leaves is crazy.


----------



## POTUS

Puffin Afatty said:
			
		

> :farm: When I refer to light penetration, I mean the distance the light remains effective during flowering
> 
> With a 400w hps lamp, the effective radius is 22 inches from the lamp in all directions, 33 inches with a 600w and 53 inches with a 1000w
> 
> any buds beyond the radius will not get enough light :hubba:


 
Interesting way of looking at light distance. In your case, what would the word "penetration" mean? What is the light penetrating? I think a more accurate method of expressing your view of this would be to say "The effective distance of the light". Since the light isn't penetrating anything but air. It's confusing to the newbies to use the word "penetration". It makes them think that the light needs to actually hit the lower parts of the plant, which isn't true. The lower parts of the plant gain from the total light striking the plant. The upper portions of the plant have more buds because the plant is genetically dispositioned to form buds nearest the top of the plant for protection of the seeds from seed eating predators. The lower part of the plant is barren mostly for the same exact reason.


----------



## Puffin Afatty

POTUS said:
			
		

> Interesting way of looking at light distance. In your case, what would the word "penetration" mean? What is the light penetrating? I think a more accurate method of expressing your view of this would be to say "The effective distance of the light". Since the light isn't penetrating anything but air. It's confusing to the newbies to use the word "penetration". It makes them think that the light needs to actually hit the lower parts of the plant, which isn't true. The lower parts of the plant gain from the total light striking the plant. The upper portions of the plant have more buds because the plant is genetically dispositioned to form buds nearest the top of the plant for protection of the seeds from seed eating predators. The lower part of the plant is barren mostly for the same exact reason.


 
_*Yes, my use of penetration is gramatically clumsy, when effective radius does a better job of conveying the message. *_

_*Semantics aside, *__*the lower part of my plants are anything but barren, as I use the lower portions to regenerate.  If you keep the lower portion of the plant within the effective radius, it will grow buds just like the top, again, it's an energy thing.*_

_*Outdoors you dont have this issue as the sunlight has adequate energy where ever it happens to strike the plant.*_

*your issue seems to be with folks claiming it necessary to remove leaves to allow lower areas within the effective range, to get some light from above.*
*I have to agree, it seems counter productive to remove anything contributing to the growth of the plant, when you can simply bend the plant to allow the light to reach everything within it's effective range  *


----------



## POTUS

Puffin Afatty said:
			
		

> Yes, my use of penetration is grammatically clumsy, when effective radius does a better job of conveying the message. Semantics aside, the lower part of my plants are anything but barren, as I use the lower portions to regenerate. If you keep the lower portion of the plant within the effective radius, it will grow buds just like the top, again, it's an energy thing. Outdoors you don't have this issue as the sunlight has adequate energy where ever it happens to strike the plant. your issue seems to be with folks claiming it necessary to remove leaves to allow lower areas within the effective range, to get some light from above. I have to agree, it seems counter productive to remove anything contributing to the growth of the plant, when you can simply bend the plant to allow the light to reach everything within it's effective range.


My issue is really with the phrase itself. When someone says that a certain light has "better penetration", it's makes me cringe. The phrase is meaningless. You can just as well say: "This will increase the speed of photon impact on the epidermis of the leaf to facilitate the rapid transference of energy to the receptors of the plant". It SOUNDS like it means a lot, but in actuality, it's pretty much self pumping baloney.

BTW, I disagree with you on the lower parts of the bush producing equally with the top. After growing many thousands of plants, I have yet to see one that did so. If you cut the top off, then the bottom becomes the new top, hehe. Please show me a bush that has an equal amount and size of buds that the top of the same plant does.

Not trying to argue with you man. Just trying to sort the facts for the newbies that are on their first grows. Too many misconceptions are being propagated.


----------



## slowmo77

so does it matter if light hits the lower buds or not? 
  does the light hitting the top leafs feed the lower leaves as well? 
  will the buds stay the same size on lower parts of the plant if they get direct light or indirect light?


----------



## trillions of atoms

i agree, the use of the word penetration is a bumbled one....i to -prefer bending and tucking.

cutting only to take clones or fim. 


I think they look at crowding and try and explain the lower buds not getting light with the word penetration.

All this talk of penetration makes me wanna call that 555 number :rofl:


----------



## POTUS

slowmo77 said:
			
		

> 1. so does it matter if light hits the lower buds or not?
> 2. does the light hitting the top leafs feed the lower leaves as well?
> 3. will the buds stay the same size on lower parts of the plant if they get direct light or indirect light?


 
1. No. You'll gain no over-all weight by lighting the lower branches. The light will be much more effective if directed at the upper branches. The plant sends a growth hormone to the upper branches that MAKES the top of the plant produce more. This hormone is almost absent in the lower branches.

2. To some extent, yes. However, the top of the plant is where nature will concentrate the growth hormones and resulting buds.

3. No. They will not. I'd love to see some pics of anyone who can produce a plant that does that. The weight of bud on the top branches will far outweigh that of the lower branches regardless of lighting on the lower branches.


----------



## POTUS

trillions of atoms said:
			
		

> All this talk of penetration makes me wanna call that 555 number :rofl:


 
You're a dude aren't you? hehe, don't be calling me man. I don't swing that way....hahaahahhaa


----------



## trillions of atoms

LOL i thought Smokinmom or sport was answering that line


----------



## slowmo77

this is a good thread. learn something new every day.

so what your saying is its better have alot of light above then a little all around.. its gonna process light the same way no matter whether it comes from the top or the sides. 

is that right?


----------



## Puffin Afatty

POTUS said:
			
		

> My issue is really with the phrase itself. When someone says that a certain light has "better penetration", it's makes me cringe. The phrase is meaningless. You can just as well say: "This will increase the speed of photon impact on the epidermis of the leaf to facilitate the rapid transference of energy to the receptors of the plant". It SOUNDS like it means a lot, but in actuality, it's pretty much self pumping baloney.
> 
> BTW, I disagree with you on the lower parts of the bush producing equally with the top. After growing many thousands of plants, I have yet to see one that did so. If you cut the top off, then the bottom becomes the new top, hehe. Please show me a bush that has an equal amount and size of buds that the top of the same plant does.
> 
> Not trying to argue with you man. Just trying to sort the facts for the newbies that are on their first grows. Too many misconceptions are being propagated.


 
_*again with semantics, ok, I'm not an english grammar teacher*_

_*:farm:  your gereralizations aside again, my point about the lower branches producing if given the light, is illustrated in my little thread on the regeneration of my current stash plant, SnowWhite, the bottom branches made the largest colas.  Hard to tell, but the bottom is the left side, since She is horizontally inclined, again, so to speak:hubba:*_


----------



## Aurora_Indicas_Dad

you probably read a post of mine.i like the sounds of "the light puts out 95,000 lumens of light which is sufficient to penetrate 3 1/2 feet into the canopy of the plants" its alot easier for a noob reading it.i think your just a lil shy when it comes to the word penetration. not only is it how we are all put on this earth,but its also used when talking about lighting.my directions for hydroponic systems used the word as well.we are all young and old adults in here and should beable to hear the word penetrate without thinking of intercourse =) i mean come on,dont we all like havin sex? last i checked we all have hormones.if your old and cant perform anymore,no need to get shy when ya hear the word...i dont whayelse to say,but thats my $.02 about  this topic


----------



## lyfr

i aint to smart so i apologize for jumpin on the "penetration" bandwagon.  i will no longer be using this term as not to confuse people wrong/sloppy term.  i have a 400 and i would never say buds at bottom are as big as buds on top,  i dont care if you flower from seed and they only get 10" tall, they wont and they haven't.   but in my measley 4 and3/4 grows, *I* have noticed that the canopy's (top of plants for newbs )  that have gotton taller than 24" have had very airy buds with little trich's on the bottom.  the one's that stayed around 18" have had *much* denser buds with many more trichs. i just happen to have some now that are 18" and 4 1/2 wks flower and i get a pic of a bud on the very bottom of plant at lights on to show this...i will include a pic of the tallest closest-to-light bud for comparison.  *my point* is simply that the bottom buds will be *extremely* better if plants are kept shorter when using smaller lights...never meant to portray that they would be = to top buds...but i ain't so smart.
    and i never cut anything of my plants ever...and wouldn't suggest doing it at all in flower.
   just to make sure i learn something*, are you saying no matter how big your plant gets with any light the bottom buds will remain  exactly the same...as in with a 400hps,  bottom buds will be the same whether plant is 12" tall or 48" tall?  *Not trying to start an arguement just want to understand so i wont be misinforming people, as i like to help.
    great discussion BTW !


----------



## slowmo77

im gonna say that i hope no newbies read this thread.. you guys have confussed the heck out of me.. some ones signature says if you can't explain it simply, you simply don't understand it.. i think thats what we have here.

is this how it works..
this is just for education not a fact

400000 lumens from above = 2 oz of bud
400000 lumens from the side = 2 oz 0f bud 

is that what your saying? the light no matter where the plant recieves it produces the same amount of bud? due to the plants hormones it sends the big buds to the top and lower buds will remain the same no matter what? i really am confused at this point.


----------



## slowmo77

i wouldn't call this an argument at all. as far as i know know one is angry or i hope they're not. this is all confussing


----------



## lyfr

as long as were getting the "terms" straight..."penetration" is a WORD...not a "phrase" !  im done here...this thread is for nothing but creating conflict by nitpickin  word usage....IMAO, of course


----------



## Aurora_Indicas_Dad

lol,i agree.it doesnt matter how we explain stuff.i understand the word and terminology of the word completly and see no need to ask why someone used it in a thread.now please close the thread =)


----------



## Dub_j

light penetrates the canopy area, onto the stem and places where new growth is, doesn't it?  a canopy of a plant is not one or many leaves, but the general area, so if light bounces around and ends up through the canopy didn't it penetrate something?


----------



## TheEnhancementSmoker

It might be a good idea to go ahead and change the name of this forum to "Cannabis Sativa, Indica, and Ruderalis Passion," to help eliminate any confusion from the vague "marijuana" nomenclature.


----------



## Aurora_Indicas_Dad

lol


----------



## POTUS

TheEnhancementSmoker said:
			
		

> It might be a good idea to go ahead and change the name of this forum to "Cannabis Sativa, Indica, and Ruderalis Passion," to help eliminate any confusion from the vague "marijuana" nomenclature.


 
The best part of it is that the thread has nothing to do with the meaning of the word penetration.

Pretty funny that you thought so.


----------



## TheEnhancementSmoker

POTUS said:
			
		

> The best part of it is that the thread has nothing to do with the meaning of the word penetration.
> 
> Pretty funny that you thought so.


 
Well, then what did this mean in your first post?
1. What is "Penetration"?


I have no idea what your point is.


----------



## POTUS

TheEnhancementSmoker said:
			
		

> Well, then what did this mean in your first post?
> 1. What is "Penetration"?


 
It was used in context with the rest of the post. That context made it clear that I wasn't looking for a definition of the word, but an explanation of how it applies to increasing the value of a grow.

After more than 40 years of growing weed, I'm sure I know what I'm talking about.


----------



## Aurora_Indicas_Dad

i'd hope so,but no need to nag on people for usin the word,right?


----------



## Dub_j

who cares get lifted!


----------



## POTUS

Aurora_Indicas_Dad said:
			
		

> i'd hope so,but no need to nag on people for usin the word,right?


If you think that's what I was doing, then you didn't understand what I said.

You need to go back and try to understand what it is that I said.


----------



## Rogue

POTUS said:
			
		

> I keep running into the phrase "Penetration" in reference to the use of lights on an indoor grow. Statements like "Provides better penetration" and "Not enough penetration".
> 
> Scenario: A grow room that is covered wall to wall with plants. The leaf canopy of plants is in excellent health and has no openings in it as viewed from the top.
> 
> I'd like to hear everyone's take on exactly what this means to them if applied to the above scenario.
> 
> 1. What is "Penetration"?
> 
> 2. Why is penetration needed?
> 
> 3. What happens if penetration is not present?
> 
> Please answer these questions specifically in reference to the scenario as stated above.
> 
> To be fair, I have to make it clear that I believe "Penetration" to be another fallacy in the minds of over-enthusiastic growers that have picked up a trade phrase that is inappropriately used and has no real merit.
> 
> Anyone who can provide me with ANY professional reference to Light Penetration that specifically means beneficial light reaching through a plants leaf canopy to the lower leaves of the same plant and providing something NOT gained by the upper leaf canopy, please do so. I'm betting that no one can. Please don't swamp me with anecdotal stories.
> 
> I would be especially interested in any comments on the benefit of actually *removing* leaves to allow "penetration" to the lower areas of the same plant.
> 
> Please keep in mind that I am NOT trying to start an argument. I'm trying to bring a misconception to light and explain to everyone how this fiction of "Light Penetration" is a well spread myth that holds no true scientific basis or benefit.
> 
> In actuality, I would love it if someone proved me wrong with quotes from anyone who is a plant biologist or other professional in the field. Please link to any articles or studies that show me being incorrect.
> 
> Thanks,
> 
> Stoney



Well in your above example penetration is moot except for how deeply the light is penetrating the leaves from above. The light from a 23 watt CFL probably will not go very deep into the leaves to dim, not maximum usuage of the plant area able to receive light. A 400 watt HPS would have light go through the entire leaf and shine slightly on others below, maximum usuage of plant area able to receive light.


----------



## The New Girl

POTUS said:
			
		

> Ref: 2. For satisfaction usually
> Call me: 1-555-444-1212 HAHAHAAHA
> 
> The light that contacts any leaves on the plant benefits the entire plant, not just the part that the light hits. Having it hit somewhere else on the plant is pointless. The plant will create additional leaves to gather sunlight until it's maxed out or as close as possible. Removing leaves to let sunlight through to other leaves is crazy.



Wow. Thanks POTUS. I did read the other couple of pages but referenced this one as it taught me a lot. Thanks for all the info thru all of your posts on this. This clarifies so much! 
PS: Oh, and can we all be nice guys.


----------



## Tater

The canopy of your pot plants will work the same way as the canopy in a forest or the rain forest or wherever.  Basically each plant is trying to maximize its available light, if its the only plant growing then no problem.  If you have many plants growing then you could have a problem.  This is pretty simply biology.  If you have a more vigorous plant that grows above and effectively covers the lower plants then those lower plants are going to respond by stretching whether it is sideways or up doesn't matter.  Light penetration is a real phenomenon.  Go watch a documentary about the rain forest or any forest.  The reason you find sparse vegetation on the forest floors is because the light cannot penetrate the canopy.  Its the same with pot.

So to answer your question.



> 1. What is "Penetration"?



The distance that light can travel past the canopy before losing the concentration required by plants to photosynthesize.



> 2. Why is penetration needed?



It is a fundamental requirement if you want to have growth below the canopy.



> 3. What happens if penetration is not present?



All growth below the canopy will slow and eventually stop.  Any leaves below the canopy that are no longer photosynthesizing light will stop growing and eventually be cannibalized by the plant.



> Please answer these questions specifically in reference to the scenario as stated above.



The above senario has nothing (NOTHING) to do with the questions you asked.  The setup you have described is either a SOG or SCROG grow where the goal is to light the canopy as evenly as you can ignoring the lower bud sites.



> To be fair, I have to make it clear that I believe "Penetration" to be another fallacy in the minds of over-enthusiastic growers that have picked up a trade phrase that is inappropriately used and has no real merit.



Penetration is anything but a fallacy.  I'm glad you stated this was nothing more than your belief though because it is definitely not based in fact.



> Anyone who can provide me with ANY professional reference to Light Penetration that specifically means beneficial light reaching through a plants leaf canopy to the lower leaves of the same plant and providing something NOT gained by the upper leaf canopy, please do so. I'm betting that no one can. Please don't swamp me with anecdotal stories.



I wish I could.  I could point you to lots of studies involving other plants, or ecosystems of the forest floor etc none based on the study of Cannabis.   This is simply because these studies do not exist mainly because of the illegal narcotic label that has been attached to the plant.  It makes it very difficult for legitimate scientist to obtain funding for these projects.  So this leaves us with personal experience, the experiences of others, and scientific data on other plants.  This should give us enough to create a hypothesis on what would happen if light penetration beyond the canopy was increased.



> I would be especially interested in any comments on the benefit of actually *removing* leaves to allow "penetration" to the lower areas of the same plant.



This should be another topic all together as it doesn't apply to the question you asked.  Removing leaves from your plant is probably the dumbest thing you can do.  (Again I'm pulling my knowledge from outside of the Cannabis plant)  Leaves are responsible for pretty much all the basic functions of the plant.  If they receive sunlight they photosynthesis and provide sugars to the plant to be used as energy and if they are no longer receiving light are dying and yellow (barring disease) then the plant will cannibalize the plant using the leaf for energy.  Discussing the leaves actual job and life stages is also outside of the scope of this post and if anyone really wants to know about it there are plenty of botany textbooks available for free online.



> Please keep in mind that I am NOT trying to start an argument. I'm trying to bring a misconception to light and explain to everyone how this fiction of "Light Penetration" is a well spread myth that holds no true scientific basis or benefit.



I appreciate your goal you are just simply misinformed.  Light penetration through the canopy and its resulting effects on plant life below the canopy is well researched and documented.  Once again this phenomenon can be observed by taking a stroll through any forest.  While you are there look at the cut lines and roads that travel through the forest notice how dense the vegetation is on the edges of these.  This is because the forest was cleared allowing more light to hit the floor which in turn increased vegetative growth.



> In actuality, I would love it if someone proved me wrong with quotes from anyone who is a plant biologist or other professional in the field. Please link to any articles or studies that show me being incorrect.



No problem, here you go.  This is just a google search but it does a great job of demonstrating the vast amount of studies done on the topic.  Granted these are all based on other plants besides marijuana.  But as stated above there are reasons for this.
hxxp://www.google.ca/search?q=canopy+light+penetration&ie=utf-8&oe=utf-8&aq=t&rls=com.ubuntu:en-US:unofficial&client=firefox-a

Oh and to clear up a misconception (not directed at you Potus) when the topic of canopy penetration is discussed we are not talking about light penetrating through a leaf to the one's below, more of light reflection through to the lower parts of the canopy.

With all that said I think the question is misconstrued and poorly formed.  A better question would have been, does lighting below a canopy increase yield to the point of making it worth the effort.  Then you would also need to address if you are talking about single plants, large plants (say a ebb and flow bucket system with 10 plants) or small plants (say in a sog with 50 plants utilizing a screen).  The questions you have asked are all basic science and have been researched and well observed. 

I also am not attempting to instigate an argument and find your goal to be an admirable.  The problem is that you are incorrect and furthering the spread of misinformation.  It would be an interesting topic for study though to find out if overall harvest of a single plant is increased by lighting below the canopy.  Controls and parameters would need to be set out as well as clear and defined goals to the experiment.

In my opinion I do agree with you that worrying about light reaching the lower branches is a futile effort in most grow situations and most likely will not increase yields enough to be worth it.

Tater

Edited for spelling and grammar.


----------



## massproducer

Dang tater you took a lot of the words right out of my mouth.  Very well said.  Light "Penetration" deal with the law of diminishing light, which states that light will diminish by the square of the distace away from the source.  So meaning at 1 foot you recieve around 100% of the availible light, but at 2 feet you only recieve 1/4 of the light, at 3 feet 1/9 and at 4 feet you would only revice 1/16 of the availible light.  It is all about intensity.  

I agree that using a 400 and growing trees, you will always have very small popcorn buds on your lower branches, but that is because a 400, doesn't have much penetrating power.  while 3-400's will give more light and better distribution then a 1000, the 3-400's will never be able to match the 1000 in its penetrating power.


----------



## Runbyhemp

I would hold the same beliefs as Tater.


----------



## Tater

Massproducer:  I can't really comment on light intensity except that I know that it diminishes the further from the source it is.  Its probably close to what you wrote though as that seems to be the general consensus.  And your second paragraph has more to do with your first paragraph than it does with light penetration of the canopy.  Like you said its all about intensity.   

Runbyhemp: I didn't post my belief's just facts.


----------



## massproducer

Light penetration and intensity are basically the same thing, just a different way of looking at the same coin.  The only thing i am speaking about is light penetration.


----------



## Tater

Intensity describes the amount of lumens at a certain distance and can measured with or without a barrier.  Penetration describes the intensity of light after passing a barrier, in this case an canopy of leaves.  The topics although similar are still quite different.

haha man I've been watching to much startrek that last part was all vulcan like.  lol sorry I'm high and a dork.


----------



## POTUS

Tater said:
			
		

> In my opinion I do agree with you that worrying about light reaching the lower branches is a futile effort in most grow situations and most likely will not increase yields enough to be worth it.


 
I must not have made myself clear about what I'm talking about. You're obviously educated and speak intelligently on the subject.

Let me be more clear; I'm speaking strictly about indoor grows in a confined space with the proper amount of plants or LST and topping done to maximize the space and light. To apply it to a grow that has embedded problems due to improper spacing or growing techniques would be pointless. That would be like telling someone with their shoes on backward, the proper way to run. (First, turn your shoes around and do this correctly). It's the same with growing. My statements were not only my opinion, but also exactly the way it works in real life. Nothing I said was incorrect if taken in the manner I was intending.

I'm speaking of light penetration onto the lower parts of the same plant, not others as in your rain forest example. So, each argument you presented in regards to other plants being slowed would be oranges and apples. As to what you did point out about plant growth in a rain forest is correct, of course.

*IF* a plant is shading no other plant, then removing leaves from the top of the plant for no other reason than to provide light to the lower portions of the same plant would be a really crazy thing to do. It would, in fact, slow the growth of the entire plant and *lessen* the weight of the final harvested bud. That's a fact. Their is no argument that can hold water to what I just said.

Redirecting the leaves using LST would be effective IF one were trying to have side growth become top growth. If the top leaves are redirected to provide more light to the lower branches for no other reason than to make the lower buds grow larger, than I have seen in real life grows that that won't make the final harvest any better. I base this not on what some person in a biology book says, (even though it's correct there as well), I'm speaking from personal experience after growing many thousands of MJ plants indoors and trying every conceivable method of growing that I've ever heard of.

That's 25 years of indoor, dirt and hydroponic MJ and more than 40 years of growing outside.

Bottom growth of buds have never and will never be equal to the growth on the upper parts of the plant if maximum energy is provided and proportioned in any manner possible on the plant. I mean this to include interior lighting or exterior lighting of any kind and of any amount.

That said, I probably missed some of your points, but after reading your post, I see that you and I really do agree on what I was intending to say. I'm sorry I didn't make it more clear. (Ok, I was high)hehe

Peace man. Let's discuss in a peaceful manner. Antagonism isn't necessary and negative insinuations won't ever be cool.

Also, I should point out that many, many studies have been done and are currently being done by hundreds of test groups, planet wide.

The medical research being done on our favorite weed is astronomical. Look at the bibliography in any of several hundred books about MJ and you'll find 20+ more books on the subject in their bibliographies that in turn will direct you to hundreds more.

Light studies on thousands of plants of every kind on the planet has been done and as well, are being done at this moment. Lighting studies on MJ specifically? I haven't seen any by anyone at the Universities, but I'm sure there must be someone doing them. In a University setting, the professors can pretty much do anything they can think of as a study. With all the professors being of a much younger age than when I was younger, (I'm 75 on my next birthday), and much more familiar with MJ than those in the mid 1950's, I can only imagine that MJ is being studied like crazy. A search on .edu studies and MJ or it's components would probably turn up many.

Any group of medical researchers that are in a field of study that encompasses *anything* that is known to be possibly beneficial to humans or animals as a result of incorporating MJ into their bodies would have ongoing studies right now. You and I will probably never know that those studies ever existed, but we may someday benefit from them if they indeed do prove that MJ can be used medically for any number of things.

Peace! I'm glad that we agree. Perhaps not totally, but you've shown that you and I do agree on many things.

First and foremost, you like to get high. So do I !

What a small world. hehe


----------



## POTUS

massproducer said:
			
		

> Dang tater you took a lot of the words right out of my mouth. Very well said. Light "Penetration" deal with the law of diminishing light, which states that light will diminish by the square of the distance away from the source. So meaning at 1 foot you receive around 100% of the available light, but at 2 feet you only receive 1/4 of the light, at 3 feet 1/9 and at 4 feet you would only receive 1/16 of the available light. It is all about intensity.


 
I understand exactly what you're saying and I agree to this point.



			
				massproducer said:
			
		

> I agree that using a 400 and growing trees, you will always have very small popcorn buds on your lower branches, but that is because a 400, doesn't have much penetrating power. while 3-400's will give more light and better distribution then a 1000, the 3-400's will never be able to match the 1000 in its penetrating power.


This is where you and I think differently. We may think the same, but perhaps we're just saying it differently.

Plant growth in regards to light is dependant on the spectrum and the amount of lumens that come in contact with the surface of the plants light receptors. Regardless of the wattage of a light, if the same amount of lumens as described above, come in contact with the plant, then the growth will be exactly the same of that where you alter the wattage, but stay with the same lumen contact. That's simple math.

Explain something to me please; If the canopy of a plant is dense enough to present a solid wall of green leaf toward the light, what exactly is going to penetrate that wall of green? Are you talking about light passing through the leaves themselves? We have to have an understanding of exactly what it is you mean in regards to penetration in this example.

As for light distribution, it's already well known that many smaller lights will grow a much better canopy of leaf. The light intensity is simply more constant at any given point.

So, if you'll explain more to me about exactly how light penetration works and give me a growing example of what you mean, then I'll no doubt understand you better.

Thanks!

Stoney


----------



## POTUS

Tater said:
			
		

> Intensity describes the amount of lumens at a certain distance and can measured with or without a barrier. Penetration describes the intensity of light after passing a barrier, in this case an canopy of leaves. The topics although similar are still quite different.
> 
> haha man I've been watching to much startrek that last part was all vulcan like. lol sorry I'm high and a dork.


 
I don't think you sound "dorky" at all. You sound pretty well educated to me. You're well spoken and articulate.

I am wondering about the exact meaning of something you've said however. If penetration describes the intensity of light after passing a barrier, then please describe that barrier very specifically. The barrier penetration is the part I don't understand in what you're saying.

In your previous post, you said something about not meaning light passing through a leaf. I would agree. The intensity of light that has passed through a mature leaf would be so diminished that it really wouldn't count for much.

You also mentioned reflection. Given that a full canopy is presented that allows no direct light to pass through it, (unless a strong enough wind is provided to actually *move* the leaves), then reflection wouldn't take place, again, unless I'm misunderstanding what you're saying.

If you could give me a very specific example of light penetration, it would help me understand.

Thanks again!

Stoney


----------



## Tater

Well in the example you stated above with a solid wall of green their would be no light penetration.  Light penetration to me as I understand it would mean the amount of light to pass through the canopy.  So in the case above there would be none.  I understand what you are saying and I do agree with you that the results would most likely be so little as to not be worth it at all.  I've seen canopy's like that and beneath the canopy the plant is totally barren because of the lack of light.  Its cool and in this set up pointless to have an extra lighting.  

If that dosen't make sense its not your fault its mine I'm all messed up on painkillers.  Found out I got gout hurts like a mother.

PS:  Stoney I got lots of respect for you and religiously read your posts man.  None of the above was intended with any disrespect, although I do know my style can come across as stinging sometimes.  Its really meant in jest when it does.  Here's to getting high and learn how to do that more effeciently


----------



## Dub_j

POTUS said:
			
		

> I don't think you sound "dorky" at all. You sound pretty well educated to me. You're well spoken and articulate.
> 
> I am wondering about the exact meaning of something you've said however. If penetration describes the intensity of light after passing a barrier, then please describe that barrier very specifically. The barrier penetration is the part I don't understand in what you're saying.
> 
> In your previous post, you said something about not meaning light passing through a leaf. I would agree. The intensity of light that has passed through a mature leaf would be so diminished that it really wouldn't count for much.
> 
> You also mentioned reflection. Given that a full canopy is presented that allows no direct light to pass through it, (unless a strong enough wind is provided to actually *move* the leaves), then reflection wouldn't take place, again, unless I'm misunderstanding what you're saying.
> 
> If you could give me a very specific example of light penetration, it would help me understand.
> 
> Thanks again!
> 
> Stoney


the barrier is the canopy, and any light found beyond that barrier can be said to have penetrated, or passed through the barrier (canopy). regardless of how it gets there.  It seems penetration could be described as effectively maximizing light contact on all surfaces of the plant, specifically the areas that are close the the stem.


----------



## massproducer

One thing that we all must remember is that most light passes through leaves very easily, green light is the only major light that can not be used by the plant and as such is reflected so none will pass through the leaf.  The most effective light at passing through the leaf surface is far red, which causes the branch to stretch towards the light.


----------



## KGB30

Thanks for the knowledge MP members...


----------



## POTUS

massproducer said:
			
		

> One thing that we all must remember is that most light passes through leaves very easily, green light is the only major light that can not be used by the plant and as such is reflected so none will pass through the leaf. The most effective light at passing through the leaf surface is far red, which causes the branch to stretch towards the light.


I disagree with what you've said. In fact, almost all light does NOT pass through the leaf barrier of a plant. The little that does, does nothing for the plant in regards to producing usable weed.

A simple test with a light meter will prove that I'm correct. Turn your lights on over a full canopy of a 4 foot tall MJ plant that has leaf that covers the entire area.

Hold your light meter below the canopy. Write down the reading. Now, hold the meter over the canopy. You'll see that about 90%+ of the light is blocked by the canopy.

Perhaps you mean something different than it sounded like.

Please explain it more in detail.


----------



## Runbyhemp

My understanding is that the more light a plant receives the higher the rate of photosynthesis. That's what we want, right ?

"Penetration" may not do anything for the lower buds, but wouldn't light hitting lower leaves help produce healthier plants in general and bigger top buds ? I would think it makes sense to say yes.



> Hold your light meter below the canopy. Write down the reading. Now, hold the meter over the canopy. You'll see that about 90%+ of the light is blocked by the canopy.



It depends on how thick the canopy is, and what light you are using. 2 large fan leaves from adjacent plants can also be considered a canopy, as long as they provide a barrier from the light above. In this situation there is still plenty of usable light  below the "canopy" and it is most certainly beneficial to the plants.

You said that the plant will make the leaves it needs to receive light.
Isn't this a waste of plant resources. Shouldn't we be trying to give the existing leaves as much light as possible ?

I can't scientifically prove that penetration makes a difference but nor can anyone prove that it doesn't.


----------



## Tater

I can, tell you what I'll set up an experiment with a control and do it all grade school like so that it, like all good experiments, will be repeatable by anyone.  It will have to wait till winter though.  I still am of the same belief as Potus though that extra lighting to provide light below the canopy is a waste of resources.


----------



## Runbyhemp

> I still am of the same belief as Potus though that extra lighting to provide light below the canopy is a waste of resources.



So the leaves below the canopy serve no purpose then ?


----------



## Dub_j

This is kinda pointless...


----------



## IllusionalFate

Runbyhemp said:
			
		

> You said that the plant will make the leaves it needs to receive light.
> Isn't this a waste of plant resources. Shouldn't we be trying to give the existing leaves as much light as possible ?


Well put.

POTUS, I would say penetration doesn't literally mean light passing through a leaf, more like the opposite -- using the available spaces to allow more light to reach the lower leaves, which is just a way of saying the light is still effective at a greater radius. Therefore the only way "penetration power" wouldn't be beneficial is if the entire canopy had no available spaces or cracks leaving everything below dark and shaded. Even a grow area with a mostly full canopy from topping/FIMing and having the correct number of plants to maximize area isn't like this.


----------



## POTUS

IllusionalFate said:
			
		

> Well put.
> 
> POTUS, I would say penetration doesn't literally mean light passing through a leaf, more like the opposite -- using the available spaces to allow more light to reach the lower leaves, which is just a way of saying the light is still effective at a greater radius. Therefore the only way "penetration power" wouldn't be beneficial is if the entire canopy had no available spaces or cracks leaving everything below dark and shaded. Even a grow area with a mostly full canopy from topping/FIMing and having the correct number of plants to maximize area isn't like this.


 
What you've said is exactly correct with one exception. I grow all my plants to 5 feet tall prior to harvest. Long before harvest, the canopy is as tight as a virgin bride. There is no way a photon of light gets beyond the first 12 inches of my canopy. At that point, there is no "penetration" possible.

However, I am aware of the new fad of growing tiny plants. When the little ones are taken into flower, yes, having light hit the lower leaves benefits the plant. I've never grown that way, so that type of growing isn't something I'd consider.

If "Penetration Power" is synonymous with "Usable light at longer distance" as with a 1000 watt light versus a 400 watt light over a loose canopy, then I would agree with the term.

Using Hydro in my grow room doesn't allow for a loose canopy after the plants are about 12 inches tall. Reflected light hitting the lower areas after reflecting from the walls is the only way light would reach below my canopy.

I'm glad this thread cleared up the use of the "Better Penetration" phrase.

Thanks everyone.


----------



## Aurora_Indicas_Dad

lol,this threads still goin? i thaught we were done with this 2 days ago.theres a such word as penetration, and it CAN be used when talking about lighting. not to seem like an a hole but come on potus..give it up already


----------



## 100percent

The particular spectrum of a plant can have a small effect on penetration.  Light does not necessarily penetrate leaves, it travels through air.  But light interferes with itself.  Constructive and destructive interference depends on the wavelength (or in our case, the spectrum of wavelengths) of light.

Let's imagine light passing through air and it hits a leaf.  The light that hits the leaf is absorbed (with predominantly green colors being reflected) and does not penetrate _through_ the leaf.  The light that just passes the immediate edge of the leaf interferes with other waves/photons directly next to it.  Normally the waves/photons are surrounded on all sides by other waves/photons but when a leaf blocks out some light then it's not symmetric anymore.  This results in a blurring of the light at the leaf-air interface.  If you had one light bulb above a leaf you might notice that the shadow on the floor is either not present, dim, or not the same exact shape and resolution of the leaf.  That's because of interference.

So penetration, if anything, is horizontal and not vertical (assuming your lights are above the plants).  Interference causes light that normally comes down vertically to "roam" horizontally a bit.  In that sense, the light penetrates and covers more surface area.

So how does this all relate?  Interference is physically dependent on the spectrum of wavelengths.  Now how relevant is this to lights used for growing marijuana?  Well, the effect is probably small, tiny, likely negligible.  I only say this because most people use more than one bulb, place them in different locations, and there are many leaves, etc etc... the _cumulative_ effect isn't really noticeable.  Even with the simple system I described above, the effect is on the order of the wavelength itself, haha, though it does propagates as the light travels down vertically.

And of course, I say interference depends on the spectrum of light but you should all be asking by _how much_.  I'm not going to pull out my notebooks but I'll hazard a guess and say that there isn't much variability in the spectra people use.  Everyone is basically within the visible range with reds and blues and in-betweens.  You'd notice differential penetration if you experimented with a wider range of EM radiation.  (But don't do this; it's a waste and it would probably harm your plants.)


----------



## massproducer

*here is an article that I found, about the light filtering abilites of leaves.*

Plant leaves filter light. Specifically, leaves allow more far red light (720&#8211;740 nm) to pass through than red light (660&#8211;680 nm), thus altering the red:far red ratio below them. By altering light quality, plants perceive canopy shading via alterations in phytochrome photoequilibria that can result in increased stem elongation and reduced branching among other responses. Although we know filtering occurs and species can respond differently to an alteration of red:far red light, no data demonstrate variation in light filtering between species. In contrast to red:far red light filtering, leaves absorb much of the photosynthetically active radiation (PAR) incident on the leaf surface, but allow some to pass through.

hxxp://www.actahort.org/books/711/711_24.htm - Reference citation


----------



## massproducer

if no light could pass through the leaf surface then anything being shaded would quickly yellow and die, because of a lack of photosynthesized tissue.  If you research the far red spectrum then you would see that hardly any of this is absorbed by leaves, it is used by the stem to elongate and try and reach a higher concentration of light

I also have an experiment for everyone to try, and it is very easy.  First take a nice healthy leaf, any leaf, and hold it up to either the sun or your grow lights and tell me what you see.  It light could not pass through the leaf, it should look like holding up panda film, mean you see no light through the leaf, but i bet you will see a lot of difussed light through the leaf.

I now also have a challenge for everyone who blasted me...PLEASE find something that can be referenced or cited, stating that NO light can pass through a leaf surface.  Leaves are Translucent, not opaque.


----------



## massproducer

The problem with this experiment is that the law of diminishing light shows us that placing the light meter and more then 1 feet away is going to cause a drastic decrease in light with or without a canopy.  The light that is being "blocked" is mainly the green/yellow spectrum that the plants can not use that gets reflected back up, so they do not get too hot.



			
				POTUS said:
			
		

> I disagree with what you've said. In fact, almost all light does NOT pass through the leaf barrier of a plant. The little that does, does nothing for the plant in regards to producing usable weed.
> 
> A simple test with a light meter will prove that I'm correct. Turn your lights on over a full canopy of a 4 foot tall MJ plant that has leaf that covers the entire area.
> 
> Hold your light meter below the canopy. Write down the reading. Now, hold the meter over the canopy. You'll see that about 90%+ of the light is blocked by the canopy.
> 
> Perhaps you mean something different than it sounded like.
> 
> Please explain it more in detail.


----------



## KGB30

massproducer said:
			
		

> if no light could pass through the leaf surface then anything being shaded would quickly yellow and die, because of a lack of photosynthesized tissue. If you research the far red spectrum then you would see that hardly any of this is absorbed by leaves, it is used by the stem to elongate and try and reach a higher concentration of light
> 
> I also have an experiment for everyone to try, and it is very easy. First take a nice healthy leaf, any leaf, and hold it up to either the sun or your grow lights and tell me what you see. It light could not pass through the leaf, it should look like holding up panda film, mean you see no light through the leaf, but i bet you will see a lot of difussed light through the leaf.
> 
> I now also have a challenge for everyone who blasted me...PLEASE find something that can be referenced or cited, stating that NO light can pass through a leaf surface. Leaves are Translucent, not opaque.


 










Thanks for this thread it has help me out to understanding light in how react with plants & canopy.   Thank MP members


----------



## POTUS

Aurora_Indicas_Dad said:
			
		

> lol,this threads still goin? i thaught we were done with this 2 days ago.theres a such word as penetration, and it CAN be used when talking about lighting. not to seem like an a hole but come on potus..give it up already


 
If you have nothing good to say, why bother saying anything?

Don't open the thread and don't read it if it bothers you.


----------



## massproducer

I thank you Stoney because IMHO, this is a good topic of research, I always enjoy interjecting with knowledgeable members on advanced topics such as these.  IMHO, there have been many pertinient points mentioned in this thread, and it is interesting how we all deseminate the information availible or provided.

I highly respect most everyone who has contributed to this thread.  I say keep the info coming as long as it is relative.  I love this stuff.

Great job Stoney...You will always be stoney to me...LOL


----------



## POTUS

massproducer said:
			
		

> The problem with this experiment is that the law of diminishing light shows us that placing the light meter and more then 1 feet away is going to cause a drastic decrease in light with or without a canopy. The light that is being "blocked" is mainly the green/yellow spectrum that the plants can not use that gets reflected back up, so they do not get too hot.


 
Excellent discussion massproducer! I've enjoyed it.

Of course, the light penetration that is being referenced when "Better Penetration" is pointed out, is *usable* light for the plant.

You and I agree on the fact that little beneficial usable light is going to pass through a leaf and that light that does reflect from the leaves won't be of a sufficient amount to do much either. The only light that will have any real benefit to the plants is that which is either direct or reflected from a surface that is highly reflective.

The strength of light in this category would of course be more penetrating if a larger light is used. If this is the real meaning of "Penetration" when used as "Better Penetration" when discussing a grow, then I'm all for it.

Great talk man.

For those that did nothing but whine about this thread, next time, just don't enter threads that bother you so much. It's kind of like going into a movie you don't like and making wise cracks about it that everyone else can hear. Hey, they might like the movie. You shoulda just not went in.

Thanks for the discussion. It was fun and informative.


----------



## Tater

Yeah I had fun and learnt something as well and really thats what these forums are all about.  If all I ever saw were threads about using MJ soil or how much nutes to feed my plant when that information is all readily available I would most likely simply just leave the forum.  As long as threads like this exist and there is intelligent debate I will gladly stick around and partake.  Nice thread Mr. President of the United Smokers.


----------



## KGB30

Oh man this thread is over it was nice learning while it lasted..


----------



## massproducer

I just couldn't resist posting this... From the overgrow FAQ

Fan leaves account for the greatest area for the reception of photons on a plant, thus they account for the majority of photosynthesis which occurs within a plant. Cells in the plant's leaves, called chloroplasts, contain a green pigment called chlorophyll which interacts with sunlight to split the water in the plant into its basic components. Leaves only absorb about 15% of the solar energy that hits them, the other 85% passes through-- but they reflect all the green light, which means it looks darker below the leaf to a human than it does to the plant because our eyes are most sensitive to the green spectrum (Shipperke, 03.15.2002). 


hxxp://www.growfaq.net/growfaq/1546.htm


----------



## Dub_j

lol, even after 40 years of experience this thread remains pointless, i think people will just be confused by all the ego driven opinions.  there are so many ways to grow, the plants pretty much grow themselves once planted, it is called weed for a reason. regardless, now that we all know the meaning of penetration and how it is relevant to growing, lets not post fiction based opinions for everyone to be confused by.


----------



## POTUS

Dub_j said:
			
		

> lol, even after 40 years of experience this thread remains pointless, i think people will just be confused by all the ego driven opinions. there are so many ways to grow, the plants pretty much grow themselves once planted, it is called weed for a reason. regardless, now that we all know the meaning of penetration and how it is relevant to growing, lets not post fiction based opinions for everyone to be confused by.


 
Sorry pal, you're the one posting fiction. 

It's obvious by what you've just said that you have no idea what you're talking about. You should be silent. It's odd that you would try to pump your own ego by posting the unnecessary crap you just did, while trying to make others sound less than useful.

You're so wrong about how and why "weed" grows, that it's actually amusing to read your uninformed bull.

Please, keep posting. We all need examples of what isn't correct. You've helped supply that need.

What you CAN do is post what it is SPECIFICALLY that you think is fiction. The posters who presented it can have a chance to show their side of the argument instead of you just posting silly crap like what I just quoted.


----------



## POTUS

massproducer said:
			
		

> I just couldn't resist posting this... From the overgrow FAQ
> 
> Fan leaves account for the greatest area for the reception of photons on a plant, thus they account for the majority of photosynthesis which occurs within a plant. Cells in the plant's leaves, called chloroplasts, contain a green pigment called chlorophyll which interacts with sunlight to split the water in the plant into its basic components. Leaves only absorb about 15% of the solar energy that hits them, the other 85% passes through-- but they reflect all the green light, which means it looks darker below the leaf to a human than it does to the plant because our eyes are most sensitive to the green spectrum (Shipperke, 03.15.2002).
> 
> 
> hxxp://www.growfaq.net/growfaq/1546.htm


 
If you include all of the light that can be produced by the sun that isn't useful to plants, then yes, I would agree. We could also discuss moonlight, starlight, car lights and flashlights hitting the plants, but it wouldn't make any more sense than talking about the spectrum of light that make up that supposed 85%. Of course, the light produced by artificial means is much narrower in spectrum than that of the sun.

Plants use radiant energy of wavelengths in the 400- to 850-nanometer (nm) range.

The spectrum of electromagnetic radiation striking the Earth's atmosphere is 100 to 10,000,000 nanometer (nm). This can be divided into five regions in increasing order of wavelengths:

*Ultraviolet C or (UVC) range*, which spans a range of 100 to 280 nm. The term ultraviolet refers to the fact that the radiation is at higher frequency than violet light (and, hence also invisible to the human eye). Owing to absorption by the atmosphere very little reaches the Earth's surface (Lithosphere). This spectrum of radiation has germicidal properties, and is used in germicidal lamps.

*Ultraviolet B or (UVB) range* spans 280 to 315 nm. It is also greatly absorbed by the atmosphere, and along with UVC is responsible for the photochemical reaction leading to the production of the Ozone layer. 

*Ultraviolet A or (UVA)* spans 315 to 400 nm. It has been traditionally held as less damaging to the DNA, and hence used in tanning and PUVA therapy for psoriasis. 

*Visible range or light* spans 400 to 700 nm. As the name suggests, it is this range that is visible to the naked eye. 

*Infrared range* that spans 700 nm to 106 nm [1 millimeter (mm)]. It is largely responsible for the warmth or heat that the sunlight carries. It is also divided into three types on the basis of wavelength: 

Infrared-A: 700 nm to 1400 nm 
Infrared-B: 1400 nm to 3000 nm 
Infrared-C: 3000 nm to 1 mm. 

As shown above, with natural sunlight, it's WAY more than 85% of the available light that isn't used by plants. Many wavelengths pass directly through the leaf as though it wasn't there; "X-Rays" being the most obvious.

However, with the narrow restrictions of plant usable light, that light that can pass through a leaf from an *artificial* source of light is debatable. I'd like to read any data you have or can find that has been discovered through scientific method.

I love the grow faq, but please keep in mind that non-professionals wrote most of it. Proof of scientific claims should be able to be backed by studies done utilizing scientific method. If no proof can be found, then it doesn't mean that the data isn't correct; only that it can't be supported with proof.

Peace!


----------



## Hick

Dub_j said:
			
		

> lol, even after 40 years of experience this thread remains pointless, i think people will just be confused by all the ego driven opinions.  there are so many ways to grow, the plants pretty much grow themselves once planted, it is called weed for a reason. regardless, now that we all know the meaning of penetration and how it is relevant to growing, lets not post fiction based opinions for everyone to be confused by.



..." the plants pretty much grow themselves once planted,"... lol.. yoou should relate that to some of the folks posting in the "Sick Plants" section.. 
  ..huh.. and "I" thought it was a pretty informative discussion, carried out in a mature manner. Where contrary facts and opinions were expressed, dissected, discussed without personal insults being exchanged... at least by the "ones contributing" any relative information.   
  So called .. "weed" requires a few basic things in order to grow. Light being one of them.. But in order to "thrive" and grow to its potential, .."weed" requires quality light, in the proper spectrum, nutrients, in ratios and consistant supply, fresh air or co2 in abundance, ect. ect.  . .. "Weed" will grow with _less than ideal conditions_.. but this discussion was/is addressing more advanced  aspects of maximizing growth. Not just simply allowing it to "grow itself", and hoping for the best.
   If you have something to "contribute".. post it. If you don't, _don't post_.. pretty simple.


----------



## Dub_j

POTUS said:
			
		

> In fact, almost all light does NOT pass through the leaf barrier of a plant. The little that does, does nothing for the plant in regards to producing usable weed.



let me know if you'd like another..
i have done nothing but water and fertilize my plants, and as of now they are 5 feet outdoors, maybe i'm lucky... im not trying to be a jerk, its just seems like this thread/( your invitation  for someone to explain the prahse "penetration" in reference to lights) was more of a challenge for someone to provide more correct context than you did, rather than helping you understand the phrase.


----------



## massproducer

With chlorophyll being the main cell able to absorb light for plant use, but chlorophyll only being produced in narrow bands in the leaf, it would lead me to believe that the excess usable light must either pass through the leaf or become trapped within the leaf.  I subscribe to the passing through.

The structure of a leaf itself lends to my belief as well, as it has a transparant waxy layer on top used to hold in moisture and allow maximum amounts of usable light into the second layer of the leaf where the light absorbing cells are in narrow bands.  After that layer you are moving into the layer where the secondary pigment light absorbing cells are which absorb even less light the chlorophyll does.  After that layer we are moving into the stoma, and underside of the leaves.

Look at your very shaded leaves or buds that are close to the light, like lower buds on the main cola, I bet they will be still growing great but i also bet that they will be a very light green colour because they are recieving most of the spectrums but because they get no direct light rays they there is no green light to filter as such no green colour.


----------



## massproducer

Instead of me always trying to prove my point, why doesn't someone show me why they would think that light can not pass through leaves?  Because I failed to find anything stating the likes.

This has now evolved into the Question of

Can usable light penetrate leaves?  Which I believe it can and at a very high rate


----------



## massproducer

Lets just try and keep things civil, i love a good debate but lets try and stay above the belt.


----------



## POTUS

massproducer said:
			
		

> Instead of me always trying to prove my point, why doesn't someone show me why they would think that light can not pass through leaves? Because I failed to find anything stating the likes.
> 
> This has now evolved into the Question of
> 
> Can usable light penetrate leaves? Which I believe it can and at a very high rate


 
I'll explain easily why the usable light *isn't* passing through the leaf.

Visible light and light that is usable to a plant are mostly in the same spectrum with the exception of some UV.

If you return to my statement about using a light meter beneath the plant canopy, you'll see that the lux that passes through the leaf is degraded to the point of almost not being there.

That's the same light that the plant needs to use.

The very first layer of leaf might actually let enough light through to help the second layer, but that's two layers of what? Twenty or so?

By the time the light has reached it's stopping point, it's not reached anywhere near the bottom of the canopy of plants that form a thick canopy at the top, (four footers or so).

With a good breeze blowing through the plant, it might displace enough leaves to let light through, but that's the only light I see doing any good.


----------



## massproducer

visable light and light the plant uses are not exactly the same spectrum... Visable light is mainly in the green and yellow spectrum, which are the spectrums that plants use the least and as such reflect.  Yes we can see from 400 - 700, but we mainly see what the plant doesn't, which is right in the middle, the green and yellow, that is what our eyes are most conditioned to see.  That is a reason that a halogen bulb does really nothing for plant growth, but sure seems bright to our eyes

That is 2 layers of 3-4, you have to do a bit more research on the structure of a leaf and the photosynthesis.

hxxp://en.wikipedia.org/wiki/Leaf


*Quantum mechanical effects*
Through photosynthesis, sunlight energy is transferred to molecular reaction centers for conversion into chemical energy with nearly 100-percent efficiency. The transfer of the solar energy takes place almost instantaneously, so little energy is wasted as heat. However, only 43% of the total solar incident radiation can be used (only light in the range 400-700 nm), *20% of light is blocked by canopy*, and plant respiration requires about 33% of the stored energy, which brings down the actual efficiency of photosynthesis to about 6.6%

hxxp://en.wikipedia.org/wiki/Photosynthesis#Origin_of_chloroplasts


How can 20% of the light be blocked by the canopy if it can not penetrate the leaves.  Funny how this sound similar to the numbers that I posted in an earlier post, where the overgrow synopsis on fan leaves stated that up to 85% of light pass through leaves with the plant's cells only absorbing 15% 

So are you saying that you have tested your theory with a light meter?  Because as I said, all of the research I have been doing are showing me that light can easily pass through leaves.


----------



## massproducer

To me it is somewhat simple...If light were blocked by leaves then firstly leaves would have to be opaque, which we know they are not, they are more like smoked glass, and light sure gets through smoked glass, secondly you couldn't grow buds that were being shaded because they would recive absolutly no light, but I also know that that is not true, shaded buds grow find, just a bit lighter green because they are no getting enough green light to reflect.


----------



## massproducer

A light-adapted eye generally has its maximum sensitivity at around 555 nm (540 THz), in the green region of the optical spectrum 

http://en.wikipedia.org/wiki/Visible_spectrum

So we see light mainly in the green spectrum, but that happens to be the exact colour that plants can not use and so reflect it.  This is the reason I can understand that people would think that light is just reflected if not absorbed, but in fact it is just because we have an easier time seeing the green that is being reflected while the wavelengths that are passing through we have a much harder time seeing.  That will cause it to look rather dark under the canopy but that does not mean light is not passing through


----------



## POTUS

massproducer said:
			
		

> So are you saying that you have tested your theory with a light meter? Because as I said, all of the research I have been doing are showing me that light can easily pass through leaves.


 
Yes, I've seen the lux drop under a full canopy. The plants were just going into flower and almost no light was reaching below the canopy. A friend who was a professional photographer was taking pics of his grow. I wasn't close enough to see the digits on the meter, but the reading dropped like a rock. He had to use supplemental light to take his shots.

If you can borrow one from someone and do the test yourself, you'll understand what I'm saying.

I think perhaps we're disagreeing on what light passes through a leaf. I'll have to dig a little and see if I can come up with some reputable studies that mention the subject matter in enough detail to mean something to our discussion.

I mentioned scientific method in an earlier post. Again, I have to caution you that neither Wikopedia nor most of the quoted "scientific" facts in the Grow Faq are the results of scientific method. I'm sure there are lots of facts on this subject that *are* proven via scientific method, and I'll try to find some on the net.

If you have any test results that have proven your argument via repeatable testing using scientific method, then I would love to read it and would gladly admit having learned something different from what I currently hold true.

From: The Solar Greenhouse Book

Only 37% of the energy in sunlight is within the wavelength (colors) useful for photosynthesis, while 62.4% is infrared (thermal energy) and the remaining 0.6% is ultraviolet. Photosynthesis in the plant leaf is powered by 1% of the sunlight that falls on the plant, 10% of that 1% is reflected and *10% passes through the leaf*. The leaf will retain 80% which is used for transpiration. Some of the light is re-radiated, while the fraction that remains is used for building food from the carbon dioxide, minerals and water.

****

The 10% that passes through the leaf will then follow the same ratios when it strikes the second leaf from the top, which on my grows is about 4 inches below the top layer. By the time the light has passed through two leaves, virtually no usable light remains. It's mostly green and at a very reduced intensity.

If you like, I can order that book and research it's bibliography. Through a simple trail of references, we can dig up a cart load of data on the subject.

Do you have a library near you that you can order books through the "Intra-Library Loan" service? Mine does for any book in print. All I need is the ISBN number and about three weeks.

If you do, you can order a few for review and I'll do the same. We'll have a ton of references that will show the test results from repeatable testing via scientific method.

We can put this on hold until the data is collected.

Paperback: 328 pages 
Publisher: Rodale Pr (February 1978) 
ISBN-10: 0878572228 
ISBN-13: 978-0878572229 

The Solar Greenhouse Book (Paperback)
by James C. McCullagh (Editor) 

Interlibrary Loan / Purchase Request
Your request has been successfully submitted, you will be contacted when the request has been fulfilled.

***
I'll get this one and see what references he has.


----------



## POTUS

massproducer said:
			
		

> A light-adapted eye generally has its maximum sensitivity at around 555 nm (540 THz), in the green region of the optical spectrum
> 
> So we see light mainly in the green spectrum...


 
No, that's not what that means at all. It means exactly what it says; "Maximum sensitivity", not mainly seen. The human eye sees all the spectrum's from blue to red. Literally, if we didn't, we couldn't see a "rainbow" or any prism deflected colors clearly. Green would be the brightest and sharpest if that were true. We see almost all the colors at close to the same intensity. We are just "more sensitive" to green variations.


----------



## Tater

I have nothing to add other than encouragement.  These are the types of threads that belong in grow faqs well once we sort the wheat from the chaff.


----------



## POTUS

Dub_j said:
			
		

> let me know if you'd like another..
> i have done nothing but water and fertilize my plants, and as of now they are 5 feet outdoors, maybe i'm lucky... im not trying to be a jerk, its just seems like this thread/( your invitation for someone to explain the prahse "penetration" in reference to lights) was more of a challenge for someone to provide more correct context than you did, rather than helping you understand the phrase.


 
"let me know if you'd like another.."

I have no idea what you mean by this. Please explain it in a complete sentence.

"the plants pretty much grow themselves once planted, it is called weed for a reason."

Another quote of your opinion. It seems that you don't follow your own judgement very well; "i have done nothing but water and fertilize my plants", well, that's NOT what happens to weeds. Please tell me the last time you went out and watered and fertilized the weeds in your yard. Exactly, NEVER. You've supplemented the actions of nature by providing more water than nature did and you also provided nutrients that weren't supplied by nature.

"im not trying to be a jerk, its just seems like this thread/( your invitation for someone to explain the prahse "penetration" in reference to lights) was more of a challenge for someone to provide more correct context than you did, rather than helping you understand the phrase."

It seems that the only thing you have done is to post comments that make you sound like a jerk, so denying it is pointless. Obviously, the discussion is beyond your comprehension. I would suggest that you be quiet and try to learn something.

Frankly man, your story gets worse every time you post. Instead of being a smart mouth to gain attention, I would suggest that you stop posting until you know what it is you're saying.

Maybe you'd be happy at one of those other groups where people look up to wise azzes.

This one doesn't.

If your comment "let me know if you'd like another.." means to let you know when I want you to post more nonsense, then I'll tell you the obvious now; I'd like you to be quiet until you have something worthwhile to say. However, people who act like you are seldom keep quiet. It seems against their nature and doesn't get them the attention they require, so I have no doubt we'll hear more negative baloney from you.


----------



## Tater

Whoa whats that all about?  If you don't want to be part of the discussion and are happy with the way you are doing things then fine don't be part of the discussion.  Other people (including myself) have enjoyed this thread and have been able to take something from it.  Whats wrong with debate and discussion?  Its you that is out of line, and the back button is located at the top of your browser feel free to use it if you don't like what you are reading.


----------



## massproducer

Wow, what happened here.  Good info Stoney, I don't understand why things have to be like this.  I am done as well, but it was good while it lasted.  Good info stoney


----------



## POTUS

massproducer said:
			
		

> Wow, what happened here. Good info Stoney, I don't understand why things have to be like this. I am done as well, but it was good while it lasted. Good info stoney


Thanks massproducer, after reflecting on the issue, I've decided to continue with our discussion. I'm not going to let a couple of people with bad attitudes stop me from having a decent conversation.

I'll retrieve that first book, read it, gain the bibliography from it and go from there.

We'll continue in a few weeks when the book comes in.

Stoney.


----------



## Hick

Sorry mass', potus, kgb, tater... and anyone else that has been following along, possibly learning something along the way.
  I guess some failed to "grasp" the message from my last post. 


> If you have something to "contribute".. post it. If you don't, don't post.. pretty simple.


  I will be monitoring this as much and as often as is feasable. Please, carry on the discussion. I'm sure the 'greater' majority are enjoying and learning something from it.


----------



## Larnek

Tater said:
			
		

> In my opinion I do agree with you that worrying about light reaching the lower branches is a futile effort in most grow situations and most likely will not increase yields enough to be worth it.
> 
> Tater


I kinda want to go back to this statement and see if I can prove it false. I'll even try to close with a little guesswork on penetration! By no means am I a MJ expert, the complete opposite in fact. But I am almost done with a degree in biology and have studied effects on some plants, but not those with fruiting bodies or other special production (THC etc.) Its well proven that the more area of canopy and leaf that a plant has light hit, the better off that plant will be. The chloroplasts in a leaf have special compounds that absorb the energy of photon. This energy is used during the carbon cycle to fix carbon and create the sugars in the plant. The sugars are then transported thruout the plant and used to grow. So if you have a great canopy that blocks light to the bottom, the canopy is using that light energy for the benefit of the whole plant, yay! However those lower leaves are receiving photons with less energy and are unable to pass off as many electrons to the carbon cycle, thus less sugars. Lighting the plant from the bottom and sides will increase the area of leaf that is receiving optimum lighting, thus increasing the sugars produced, thus increasing the productivity of the plant. I'd love to do an actual test of this but I have a very small area for growing, and its just not worth it to me to have plants that may produce less than optimal results right now. My whole argument is likely only viable in an indoor environment. The amount of energy given off by the sun is far more than what lighting with under lighting would do for you. The reflection of sun off the ground is likely more than manmade lighting can do! (At least with reasonable expense). So my conclusion there is that throwing a couple CFLs or such under the canopy will indeed give more energy to the plant and thus should increase the yields all over the plant, not just at the base buds.
As for penetration I'd have to hazard and guess that light from a larger light source would have photons of a higher energy level (quanta) and so give more light to those leaves beneath the canopy. If I can remember my hated chemistry right photons have different energy levels corresponding to amount of electrons that can be knocked free. This is dependent on the amount of energy that created said photons as well as the wavelength in which is travels. This is where it gets tricky as you have to delve into quantum physics where light becomes a particle as well as a wave and is seriously wacky and more in depth than I want to remember. Basically the photon (particle) of light strike the chloroplast and gives energy to electrons in the chloroplasts freeing them from their bonds. The number of electrons knocked off would be equivalent to the number of electrons the chloroplasts are able to move to the electron chain which feeds the carbon cycle. This part is true, I even went back and grabbed my old notes! What I don't know for sure is whether or not a 1000w light actually creates photons of a high energy level or just more photons on a whole. If they are stronger they would:
1. Give more energy to those chloroplast stacks per each photon.
2. If the stack is bombarded with more photons than it can use at one time its possible for those photons would actually pass thru the leaf matter as a high energy photon has been shown to pass through solid matter. Or bounce off where it could be reflected by another leaf and end up traveling farther deeper into the canopy than a photon at a lower energy level. Both would truly give that higher wattage light a deeper penetration.

Where it is also tricky is that I don't know what exactly a lumen meter reads. If it reads the wavelength of light it would indeed be less under the canopy even tho there are still high energy photons bouncing around because the speed in which said photon travels would be disrupted, altering the wavelength. 
So there is my brief hypothesis on both the lighting and penetration factors. Take all of that with grain of salt as I have no experimental proof saying that is what happens, I'm just using the concepts that I know. I'd love to test it someday, or I'd try to help setup a experiment where we could legitimately test this hypothesis. If only my school would let me use their funding and equipment....


----------



## POTUS

Hello Larnek, well thought out post. There are a few things that have to be considered in your offered hypothesis.

1. Plant hormones and how they're used by the plant.

2. Light reflection is virtually non-existent from the canopy.

3. Individual Photon strength doesn't vary in this application to any useful degree. The amount of Photons most certainly does, but in essence, that results in only more Photons being reflected by the canopy. Not enough pass through the physical leaf to matter and unless the leaf barrier is disturbed enough to allow light penetration, the additional light would only be added to that which is already reflected by a lesser strength light.

However, the amount of light that can be utilized by the plant is much more than most people direct at the plant. Natural sunlight supplies approximately 10K lumens per/sq ft on a clear day at the equator. To supply this amount in an indoor grow would cause an offset cost to deal with the generated heat and wouldn't be economically feasible. With the cost factors considered, a 5K lumen per/sq ft supply is about as large as anyone would want to go. The results balance with the costs of maintaining a proper environment for the plants.

4. Ground reflection is something that is not desired. When the underside of a leaf is hit by reflected light, the plant enters into a competitive cycle of growth. The plant reacts to the reflection as being from another plant that is competing for the available light. The plant reaction will be to send more growth hormones to the stems to enable them to grow faster and taller, thus outgrowing it's neighbors. With MJ, this is counter productive in an effort to maintain close intranodal length to maximize bud production per/cu ft of available space. This problem of competitive growth as a result of reflected light is a well known phenomenon that is most obvious in the low light conditions of the lower branches of tall plants.

5. If more lumens are provided to the lower branches while leaving them in their natural position, the result will be negligible. The plant will continue to send most of the growth hormones to the upper branches and as a result, the lower branches will benefit only slightly from the additional light. The exception to this is when LST is used to redirect the hormones to alternate locations on the plant. If this is done, the "new" top growth will show a marked increase in growth as a result of the redirection of plant hormones. If this new top growth is what *was* bottom growth prior to the redirection, then yes, the now top growth will be heavier with bud growth in respect to MJ. However, the "old" top growth, now not receiving the same growth hormone levels it was, will negate any advantage of the effort. Nothing will be gained in regards to harvest weight.

I think I covered each of your ideas. Your thoughts are well directed, but have already been tested via scientific method and the results published in countless articles.

Great post man! Gains cannot be realized until *someone* pushes the envelope. Sometimes, the known steps must be done over and over with only slight variations to discover something that has inadvertently been missed by everyone else.


----------



## Larnek

I was actually unaware of the ground reflection causing stretch, not surprising as I'm not a plant major but a microbio major, just had to do some of those classes on the way. Interesting stuff!
The thing I think about lighting the bottom is this:
1. I'm not worried about increasing the size of the bottom with lighting, tho that may or may not occur. I'm saying that the increase in sugar production allowed by further lighting of the bottom should increase the amount of energy that is given to the top areas of the plant, which should increase the size of the top cola(s). I'd think that the increase in production would more than offset cheapness of running 2 or 3 CFLs lighting the bottom. That was my mine hypothesis, I sort of rambled off after that.  Basically what I'm saying is the more area of leaf that can be used to produce sugars should then increase the total yield of the plant. Maybe not a huge increase in any one area, but a small increase over a large area of buds, (especially if you're doing 5 foot indoor trees!?) would be significant. 1/2 gram or so per bud site over such a huge plant would end up pretty significant in my opinion.


----------



## POTUS

Larnek said:
			
		

> I'm saying that the increase in sugar production allowed by further lighting of the bottom should increase the amount of energy that is given to the top areas of the plant, which should increase the size of the top cola(s).


I agree, providing the side light was added in a manner that prevented any bottom leaf lighting. I seen people put linear fluorescents down the middle of the plant in a manner that made it impossible for the leaves to adjust position enough to redirect the leaf tops towards the light. When light is coming from as many as three directions at once, it becomes a negative influence instead of a positive addition.

Whether or not the additional bud growth would offset the cost of the additional lighting would of course be determined by how much current draw resulted from their use as compared to the amount of weight increase after curing. If proper testing was done, it would indeed be interesting to find out.


----------



## Larnek

Yeah, that's what I was saying, definitely one of those things you'd have experiment with scientifically as possible, same strain, same nutes, same grow condition other than one gets lit from above, other from a side or some other way that'd have to be figured out. Of course since I'm one of those people with linear fluorescents I guess I'm a potential test subject. I will be using the same strains next grow, tho its nirvana's citral which from reading here is notoriously unstable genetically so even then it wouldn't work great.


----------



## 100percent

Larnek said:
			
		

> As for penetration I'd have to hazard and guess that light from a larger light source would have photons of a higher energy level (quanta) and so give more light to those leaves beneath the canopy. If I can remember my hated chemistry right photons have different energy levels corresponding to amount of electrons that can be knocked free. This is dependent on the amount of energy that created said photons as well as the wavelength in which is travels. This is where it gets tricky as you have to delve into quantum physics where light becomes a particle as well as a wave and is seriously wacky and more in depth than I want to remember. Basically the photon (particle) of light strike the chloroplast and gives energy to electrons in the chloroplasts freeing them from their bonds. The number of electrons knocked off would be equivalent to the number of electrons the chloroplasts are able to move to the electron chain which feeds the carbon cycle. This part is true, I even went back and grabbed my old notes! What I don't know for sure is whether or not a 1000w light actually creates photons of a high energy level or just more photons on a whole.


There are two things you need to consider when dealing with photon beams: intensity and energy.  The intensity concerns _how many_ photons per unit area are striking the plant's leaves.  The energy deals with the energy of _each individual photon_.  Think of intensity like traffic on a freeway (light or heavy) and energy like the speed of the cars (fast or slow).

Intensity
With bulbs, intensity is the strength or power output.  It's basically how many lumens the bulb emits.  A 2000 lumen bulb will do the same job as two 1000 lumen bulbs.

Energy
With bulbs, energy is the spectrum of the light.  Ever heard of warm or white or sunlight or (insert description of light) bulbs?  These depend on the energy of the light.  Sometimes you will see a temperature on the bulb package, like 4000K, 5500K, or 6500K.  (The K stands for Kelvin, the internationally accepted scientific standard for temperature.  To convert to Celsius just subtract 273.)  Obviously the light bulb isn't actually getting that hot; this just denotes the spectrum of energy that would typically be emitted by black body radiation at that temperature.  Hint: the sun can be considered a black body.  Wikipedia says the sun's surface temperature is 5778K and that's why if you're using fluorescents, many suggest getting 5500K bulbs.  That is, they mimic the sun's light spectrum.  Two 2500K bulbs *WILL NOT* be the same as one 5000K bulb.

If you remember the first equations they taught in Physics, energy is dependent on the wavelength of light.  Since light bulbs emit many wavelengths it's appropriate to talk about the spectrum of wavelengths.  But as *Larnek* pointed out, light is best described using a wave-particle duality theory.  That's why you can think about discrete photons (particle) that have a wavelength (wave).  There are some really neat experiments that show how light _simultaneously _acts as both.

Photosynthesis
The electrons everyone's concerned with are in the reaction center of the chlorophyll.  They are highly-conjugated systems that have evolved to have the same energy gaps that correspond with the strongest portions of sunlight's energy spectrum.  Basically what happens is photons, either from the sun or your bulbs, hits the pigments in the reaction center of clorophyll.  These pigments have their electrons excited, redox reactions occur, etc ad nauseum.

Putting it all together, a stronger bulb will produce more photons.  More photons hitting the leaf will cause photosynthesis to proceed faster and the plants will grow faster.  A stronger bulb will emit approximately the same spectrum as a weaker bulb.

One might ask if a bulb with more energy would help.  If a bulb was used with a spectrum that had more high-energy wavelengths than low-energy wavelengths, what effect would that have?

Think about it.  The plant's pigments have spent millions of years evolving to match the sun's spectrum as best as possible.  If the sun's spectrum peaks at XXX nm, YYY nm, and ZZZ nm (nm=nanometer, a convenient unit of measure for wavelengths), then the top three pigments in the chlorophyll are best excited by XXX nm, YYY nm, and ZZZ nm light.  So a higher-energy bulb isn't necessarily what you want.  The farther you shift your bulb's spectrum from that of sunlight, the less energy the pigments can absorb.  The thing about quantum mechanics is that energy levels are discrete; you can't just pump in any amount of energy.  The electrons need discrete quanta and giving it _too much_ energy (like UV light) won't help.

If you've ever thought about LED lights, they work by emitting a very small range of wavelengths.  A light bulb that encompasses all visible light will have wavelengths of 400 nm to 750 nm with portions at higher (infra-red) wavelengths, too.  LEDs only deliver a few Watts of light but they invest it all in one (in reality, a small range) wavelength.  That's why they always have a color; blue LEDs emit 450-460 nm.  Their wattage is low so the intensity is low; few photons are being emitted compared with other bulbs.  But the energy is tweaked the match precisely the energy pigment electrons need to enter photosynthesis.  So the argument for LEDs is that they use less power but more of it is absorbed by the plant.  (I understand the many arguments but I won't present them here.  I'm just trying to apply quantum mechanics to LEDs as an example.

This whole reply was basically a lesson on the symantecs of intensity and energy.  Gotta go harvest now!


----------



## POTUS

Thanks 100%, that was a hell of a post! This is the type of information that is needed in abundance here on MP!

To be totally honest, the starter post I made for this thread was an attempt to gather some posts that contain pure information that has been discovered and confirmed through proper scientific method.

I was starting to see too many anecdotal instructional posts and too few really informative, accurate, detailed posts.

Please help the site with more information about anything you might feel beneficial to the group.

The next time you start thinking of some of the more detailed and specific points of interest in growing our favorite plant, please start a thread to examine that process in detail. This is something the entire group can benefit from.

Thanks again, and I look forward to reading more of your information in the future!

Stoney.


----------



## Larnek

100percent brings up a point that I would love to experiment with sometime as well. I'm really interested in using LEDs not as a main light but as a supplemental with my HPS. I think LEDs would far far FAR surpass fluorescents as a supplemental due to the specificity of the light wavelength. I think growing with just LEDs is a bit of a pipefream as far as big yields are concerned. Just not enough light energy for the plant to produce large buds. But I think with an HPS the LEDs would give a much needed boost to plants. People complain about the stretch the HPS produce in veg and even in flowering. I wonder if LEDs would allow the plant to reduce stretch in flower with the HPS. I know that they stretch in flower because thats what they're genetics tell them to do, but I'm curious as to whether or not LEDs would reduce the stretch and promote more bud growth. Just something I've been wondering about while reading some guys grow journals here with LEDs. No one has used them as a supplement yet and I want to know! I'm also still kinda messed up from a late late late night/morning partyathon so I hope this makes sense.. I wish I had some bud now to help out with the dead feeling.
Oh and pretty awesome for one of your first posts 100percent.


----------



## POTUS

Larnek said:
			
		

> I'm really interested in using LEDs not as a main light but as a supplemental with my HPS.


From what reading I've done concerning NASA's quest to find the absolute best form of plant growing that can be done in the smallest space with the least amount of energy, LED's are the number one choice of lighting that they've tried so far.

Lots of our present day gadgets and commodities are byproducts of research done by NASA during it's history. Because of the inherent challenges presented by space exploration, they have drawn some of the most intelligent, best paid, perfectly logistically resourced people on the planet.

They are currently researching how to increase the output of plant usable lumens and exactly what precise spectrum and spread to use to gain the most from every watt of energy.

If you discover anything really interesting in your trials, give them an email. If you route it to the correct person, they'll read it and either dismiss it as something they've already discovered or they will call you for an interview. (No kidding).

Good luck to you in your research and I hope you stick with it until you discover something that is currently unknown.

I would keep the marijuana plant thing from them however. Perhaps you could experiment on some maters too! hehe


----------



## Larnek

No way, if I found something really important I would totally attribute it to MJ. Take that government!  
As for the LEDs I do think they are a great form of lighting, just not feasible on a private scale right now due to costs. Well to me anyways, maybe to some big timers. I was looking at some new LED grow lights, the UFOs you mighta seen, something like $600 a light- "Consuming only 80 watts of power and producing virtually no heat, it boasts light intensity and growth rates exceeding that of a 400W HPS system" they also go on to state that its good for 3x3ft areas. Very interesting but yeah that cost thing again. I'd believe that 80 watts of LEDs IS getting close to the level necessary for growth but I think you'd still need several in order to get a good yield. Long term for big grow schemes, yes I think it'd be worth it due to lessening the cost of power and ventilation systems. I'd love to see some results from that light but haven't found any yet.


----------



## Larnek

Found this test on tomatoes in a 3x2 area with the UFO with good results. So yeah its possible, still think you'd need more tho.
hxxp://www.greenpinelane.com/ufo_light_test.aspx


----------

