The Impact of Light Intensity and Spectrum-Tuning on Cannabis Yields

Chris Edward

Well-Known Member
It is never my intention to argue with those that dont seek to and surely some objectifying middle ground must be reached if there is to be an underlying agreement.

I propose that at no point have leds overtaken hps and that increase you talk about was from a very low point and that exponentially it looks like you have overtaken everyone but in reality you are still that touch behind as at the present hps and cmh growers are yielding as much and normally more than led growers (fact, wanna argue...?)

I would report on the point that recipies for light are great but they do not and neither have Phillips or the scientific community found the recipe for biological efficiency which would support led claims and wild ppfd numbers more. When there is such science you may be able to say led is more efficient biologically (not just on paper) but until that point hps might have the better spectrum and cmh even better or worse meaning in reality those that guess write checks their ego will never cash as it can be simply disproved.

Led is not constantly evolving, its thermodynamically locked to certain mathematics and physical properties - may i suggest that many here have trolled some alter science and members like Kingrow are now busy re teaching every one heat from science not the back of an led packet that says its cool or this mundane site knowledge that teaches stupidity over how to set up an indoor environment before you even hjang a light.

I see the stupidity here, most need to keep their opinion to themselves or stop bitching that its hard to find info here on a site they previously trolled to death on the day they bought an exspensive pannel.

Let me sum up -

* Led have always made claims here - so why is hps and cmh still yeilding just as much if not more....?
* The odd led grower i like - the rest are literally site ruining wankers, we all know what led has done to us and the info, why bother its just a light not the HOLY fucking GRAIL.
* Led growers keep twisting and changing stories, ive heard that better than hps for over five years since ufos hit, ive heard that not needing ir and green spectrum bs for even longer. You say these new gen are evolved and better trhan hps but again thats because were on the fith version of yet another light thats the HOLY fucking GRAIL.

One point i have always mentioned - we can troll even harder, led users need to show some respect, were not the ones that talked shite here and caused arguments only to be wrong many many many times.

Oh and we have one more thing we all avoid - SNAKEOIL. You will notice this stuff is vastly followed and supported whilst costing loads but never does what its claims make - led fits snugly here- ya its a light that works but also an exspensive rippoff that so far has made constant claims that havent once worked or the whole site here of cmh and hps growers wouldnt be telling them to basically fuck off and stop trolling the site as its clear they have been (wanna argue that they have been good for internet sites....?)

So yes i like to slice these lights and fools up a different way, far too easy to smash their science to smithereens and just keep on teaching the science of heat and indoor growing and get waaaaay more respect than these idiots. Far too easy to point out that you and leds dont really know what efficiency truly is to a plant and hence why you choose that not so accurate ppfd that has seen constant evolution brcause your constantly wrong - fool thats just you fixing what is broke many times because you cant get that right not evolution lol

If at any point you disagree then i feel that some reading on ppfd from non led sites might help rectify your discussion and save me the obvious copy and paste led growers keep giving.

Thankyou :-)

Kingrow1,

I am not even sure how to comment to your post.
I don’t want to sound like a jerk, but your responses are sort of double-edged.
At this point I think you just want to argue and I am not going to engage you.

If you want to have a proper conversation, then that’s fine but if you continue to post similar posts, I will no longer respond…
Just so we are clear.

In closing…
You get good results with a method you are comfortable with.
I get good results with a method I am comfortable with.
We both want to tell others about how happy we are with our chosen path.
Just because a path works, doesn’t make all other paths wrong.

We can argue the minutiae till we are both blue in the face and at the end of the day, both of our minds will not be changed.


So, let’s just agree to disagree.
And end it at that…
 

Chris Edward

Well-Known Member
An opinion from the distance.I am not qualified to comment on either lighting system as I use neither.I know I'm a relic( an old one).But hear me out please.Rather you like him or not kinggrow is on to something here.his complaint as far as I can see is all the hype as to how the only way to grow is with LED.folks taking cherry picked info and building on it.I don't think most doing this even realize how arrogant they sound.Its in how you present it to me.And the way it has been presented I do not want anything to do with LED.Let me explain.I am a archery nut.I love to shoot bows, crossbows,hunting is a passion of mine.In the 70s,80s,early 90s.hunting was fun.Then came the need for speed craze and if you couldn't shoot over 300 feet per second then you were not a hunter.(starting to sound familiar)new hunters were being pressed to use this equipment by the marketing and manufacturers.newbies thought all they needed was the latest and greatest equipment and they were in like flint and everyone else was stupid.problem was most of them did not know the difference between a deer track and a pig track.nothing about deer habits and tendencies exct.or in other words lousy hunters.the tech made them a better shot but not a good shot.(sound familiar)come opening day the guy using an old recurve came out of the woods with a 10 point buck and the guy with the fancy $1,500 bow came out empty handed.how could that be?See it became about the technology and not respect and understanding for the majestic animal .I have all 3, recurve,compound and crossbow.and I can take a nice buck with either.the difference is to set up according to my understanding of each.but what happened is hunting got ruined by the tech craze,hunters were found arguing about tech issues instead of sharing good helpful knowledge about the game they hunted.they were so busy fighting it was not even about hunting any more.and now very few knowledgeable hunters even left.hunting is way down to expensive for most its a shame.my point is watching from a distance I see the same thing happening to growing weed.new growers spending a fortune and having terrible outcomes.opening morning comes around and the cfl grower comes out with fist size buds and the led grower comes out with nothing.Is it the lighting ? no.the lighting might help just like the compound bow can help,but when its not about the grow and the respect for the majesty and understanding of the beautiful plant any more and about ego.then you will ruin it for the average grower,and all there will be left is the big commercial grows and you will be forced to smoke what they give you.I was told by folks on here to be a real man and step up to LEDs if I wanted to grow good weed.REALLY-REALLY .kiss my as#. They never even seen or smoked my weed before.A bunch of real a#$holes.I know not all are like that.but do not stray to far from what its about.The grow,the plant.having fun enjoying it,learning about the living thing you are growing.Its not about a damn light.I use a simple t-5 lights,1 or 2 hits and your stoned buddy.One day I may use LEDs who knows.but the absolute truth is the cost is not worth it now.the quality is over exaggerated.can it help? likely yes but seriously how much,really.If I get quart jar size buds covered in frost,then my lighting is not a problem.understand these manufactures are out to make money off you any way they can and sell you.I'm just saying be careful.OK go ahead and drill me now.Just an opinion.lets not become our own worst enemy over this subject.Lot more to say but better shut up now while I'm still behind.
@old buzzard,

I see where you are coming from.

I don’t agree with some of the things you said, but I see that your heart is in a good place.

I will leave it there…
 

hillbill

Well-Known Member
PPFD is important since it indicates how much light strikes a particular area which is really what is important in the garden. That measurement can be taken at multiple points. Also various reflectors distribute generated light in different patterns and with varying efficiency. Light from HID must be reflected since it is cast in a 360* pattern. Not so much in a vertical grow.

It is simply an objective repeatable measurement which I consider quite relevant here.
 

Chris Edward

Well-Known Member
I really think the main reason that LED hasn't stood out as better is the lack of w/w grows. Very few LED growers actually run comparable wattage, they would rather save 30% on the electric bill then get 30% more yield. Thats how it works out guys. If you run w/w of light, you should be able to expect very similar results, but probably much better from LED because they out put more photons.

I totally agree that the biggest issue isn't the difference in lights, its the egos. Some of it is old guy egos, but a lot of it is young kids that have just got into growing in the last 2-5 years. I'm sorry, but you have a lot to learn before you start preaching which lights are the greatest. The LED vs HPS debate was going on back in 2008 when I joined this site. However back then it wasn't really a debate it was hype vs results. These days, the results are there on both sides if we all open our minds and look. Set up cost is the biggest difference at this point, and that is drastically reduced if you can DYI. If you can't DYI, then in the next few years I expect to see extremely affordable LED rigs on the market. The more competition grows, and tech improves, the cheap its getting.

From everything I've seen over the years these plants want light and lots of it. So running lower wattage might get ok results, but if you want to compare 2 different lights, they need to be comparable wattage. My biggest complaint about LED is the way they are marketed with equivalent wattage ratings. That is 100% bull shit. They need to market them on how much light they actually produce at comparable wattages.

I would bet money that if you get all these LED guys running similar w/sqft to the HPS guys the results will be better if not just indistinguishable.
@Thundercat,

I agree with you, to a point...

First there is no simple way to judge LED’s against HID.
There is no number, or formula that will make it all nice and tidy.
And this goes from complicated to even more complicated when you throw color LED’s into the mix…

Adding to this complication is that the forms of testing that are being offered, (spectrum, PPFD) are being scoffed at by HID users…
Who seem fine with spectrum tests when it’s on Gavita letterhead.

Yet measurements of lumens, Kelvin, and wattage are still widely accepted ways to compare all lights…
LUMENS for a grow light!!!
Seriously?
Lumens are for humans…

Plus let’s not ignore that all LED’s are being clumped together as if they are all created equally.
I am sure HID users have similar complaints about how all forms of HID are clumped together…

All of this mumbo jumbo just makes for a mess…

It’s like people have this incessant need to be at odds with each other.
If it’s not religion, it’s politics, or it’s nit picking their hobbies to death…
People seem to search for way to have to cause a divide among themselves…

It’s sad really…
 

Chris Edward

Well-Known Member
@old buzzard could grow more of his really great weed for less power used and less heat to deal with. I don't think anyone is an asshole for using HPS. That would be like saying “I used to be an asshole.”

And we all know that CMH growers are not near the assholes that HPS growers are.

People that use fluorescents are just nice folks, like people from Minnesota!
@hillbill
Oh geez!
 

Chris Edward

Well-Known Member
The whole point of this thread, and what the study pointed out was it didn't matter which light you had over the plants.....

The study said put more light over your plants for more yield period! It stated that the cost per watt for more light was outweighed by the added yield. Soo How about we all just stop arguing over which light system is "the holy grail", and just try to increase all of our ppfd until we can actually compare with the sun.

Secondly it has always amazed me how intolerant many stoners on this site are. Calling each other names, and attacking each other for being different rather then trying to come together and become better. Not to say everyone is at all, but there are more then I expected from a bunch of weed growers. Sadly I think egos take charge many times, and closed minds don't learn new things well.
@Thundercat,
Fuck you!!!
LOL
Sorry I had to do it...

I agree with you totally!
 

Chris Edward

Well-Known Member
you told me to try owning an hps so I would understand......

how is that a nice reply?

I do own an hps and have talked about it many times on this forum, which is what makes you "clueless" for telling me to try owning one...
@Thundercat,
Now you are just arguing with yourself, I don't think Kingrow1 is listening because the responses have become less and less coherent.
 

Thundercat

Well-Known Member
First there is no simple way to judge LED’s against HID.
There is no number, or formula that will make it all nice and tidy.
And this goes from complicated to even more complicated when you throw color LED’s into the mix…
Maybe I don't understand the science as well as I think I do? Isn't comparing wattage used vs intensity at a given distance a pretty fair way to judge any light sources? I know spectrum effects it a little, but based on this article we are talking about, they don't believe spectrum means quite as much as simpley the amount of intensity.


@Thundercat,
Now you are just arguing with yourself, I don't think Kingrow1 is listening because the responses have become less and less coherent.
I learn a while a go not to bother arguing with him, I usually say my piece and point out how he's wrong If he is and move on. I was just pointing out that he was again off base with his comment. It's rather frustrating because not all his info is bad, some is valuable, but that gets clouded by his bad attitude.
 

Chris Edward

Well-Known Member
Maybe I don't understand the science as well as I think I do? Isn't comparing wattage used vs intensity at a given distance a pretty fair way to judge any light sources? I know spectrum effects it a little, but based on this article we are talking about, they don't believe spectrum means quite as much as simpley the amount of intensity.

@Thundercat,

Not with LED’s because efficiencies are always changing and are not static from one company to another.
Plus it all depends on the LED package (through hole, SMD, COB, etc.), the LED bin, the CRI number, it’s goes on to madness…

In the 1990’s when “high output” 5mm DIP (dual in-line package) blue LED’s became somewhat affordable ($5 each!!!), they had the same stats as comparable SMD 5050 LED’s do today, however 5050’s are considerably brighter (at least twice as bright), yet they have the same forward voltage and use the same milliamps…

Just imagine what will be available in 10 more years…

The PPFD measurement has to do with the amount of light that actually makes contact with the plant.
So these numbers can be easily fudged as there is no standardization and that’s sort of what the HID people are banking on...
I won’t go into it, but the numbers can be fudged…

The only way to know for sure is to do a side by side test of your own, but sadly a decent quantum meter is like $400.
As far as I know, you cannot use a standard light meter with LED’s…
Though that may be only with the color ones.
The measurements given by a standard light meter are set up for filament lights, so they will give wonky numbers for LED’s.

As far as comparing wattage, this is generally fine when comparing HID to HID or LED to LED, but not HID to LED.
***Generic efficiency numbers alert***
HID's are reported to be 30% efficient, by “them”
LED’s are reported to be 60% efficient, also by “them”

So this means a 600watt HID bulb is only using 180 watts for light and 420 watts is being wasted as heat.

A 600watt LED fixture is using 360 watts for light and 240 watts is being wasted as heat.

So, I suppose if you matched “light" watts, then you could have a test that would be close…

But in the generic example above, the HID would have to be 1,200 watts (360 “light” watts, 840 "heat” watts) and the LED would have to be 600 watts (360 “light” watts, 240 “heat" watts).

This is something I am sure the HID folks will bitch about…
It’s just an idea of a possible way to compare the amount of wattage used as light.

Spectrum affects things we are unable to measure…
Just because we cannot measure these things doesn’t mean they are insignificant.
I posted a video earlier about a guy who did a lettuce growing experiment using CFL’s, all Red LED’s, all Blue LED’s, and Blurple LED’s.
I also posted a link to a pdf showing a study done on spectrum effects.

Spectrum effects more than just growth, it affects the nutrition, taste, texture, etc. of the plant.
So it depends on what matters to you the most, higher quantity yields, or higher quality yields.
Phillip’s has spent a fortune on this topic and they are keeping a tight lip on their findings, so it must be good.
If it hadn’t panned out, they would have dumped the url and product line by now because they don’t sell to you and I (though some folks do buy the lights and resell them); they sell to large scale commercial growers who aren’t going to spend money on bullshit.

There is a similar HID –vs- LED argument for every topic out there in the world….
 

Thundercat

Well-Known Member
@Thundercat,

Not with LED’s because efficiencies are always changing and are not static from one company to another.
Plus it all depends on the LED package (through hole, SMD, COB, etc.), the LED bin, the CRI number, it’s goes on to madness…

In the 1990’s when “high output” 5mm DIP (dual in-line package) blue LED’s became somewhat affordable ($5 each!!!), they had the same stats as comparable SMD 5050 LED’s do today, however 5050’s are considerably brighter (at least twice as bright), yet they have the same forward voltage and use the same milliamps…

Just imagine what will be available in 10 more years…

The PPFD measurement has to do with the amount of light that actually makes contact with the plant.
So these numbers can be easily fudged as there is no standardization and that’s sort of what the HID people are banking on...
I won’t go into it, but the numbers can be fudged…

The only way to know for sure is to do a side by side test of your own, but sadly a decent quantum meter is like $400.
As far as I know, you cannot use a standard light meter with LED’s…
Though that may be only with the color ones.
The measurements given by a standard light meter are set up for filament lights, so they will give wonky numbers for LED’s.

As far as comparing wattage, this is generally fine when comparing HID to HID or LED to LED, but not HID to LED.
***Generic efficiency numbers alert***
HID's are reported to be 30% efficient, by “them”
LED’s are reported to be 60% efficient, also by “them”

So this means a 600watt HID bulb is only using 180 watts for light and 420 watts is being wasted as heat.

A 600watt LED fixture is using 360 watts for light and 240 watts is being wasted as heat.

So, I suppose if you matched “light" watts, then you could have a test that would be close…

But in the generic example above, the HID would have to be 1,200 watts (360 “light” watts, 840 "heat” watts) and the LED would have to be 600 watts (360 “light” watts, 240 “heat" watts).

This is something I am sure the HID folks will bitch about…
It’s just an idea of a possible way to compare the amount of wattage used as light.

Spectrum affects things we are unable to measure…
Just because we cannot measure these things doesn’t mean they are insignificant.
I posted a video earlier about a guy who did a lettuce growing experiment using CFL’s, all Red LED’s, all Blue LED’s, and Blurple LED’s.
I also posted a link to a pdf showing a study done on spectrum effects.

Spectrum effects more than just growth, it affects the nutrition, taste, texture, etc. of the plant.
So it depends on what matters to you the most, higher quantity yields, or higher quality yields.
Phillip’s has spent a fortune on this topic and they are keeping a tight lip on their findings, so it must be good.
If it hadn’t panned out, they would have dumped the url and product line by now because they don’t sell to you and I (though some folks do buy the lights and resell them); they sell to large scale commercial growers who aren’t going to spend money on bullshit.

There is a similar HID –vs- LED argument for every topic out there in the world….

First let me say I'm not here arguing anything, I'm participating in a discussion about light intensity being one of the most important aspects of our grows.

I didn't really think I was confused or didn't understand, but I thought maybe you had some info I didn't about this. You really didn't say anything just now I didn't know though.

I understand ppfd can be messed with which is why I specified the comparison tests would need to be done at a fixed height above the canopy.

The type of light source doesn't matter because wattage used is wattage used. Yes some lights produce more or less light with that wattage. That doesn't change the comparison, that is the proof in the pudding if you will.

The point of comparing lights by wattage used vs photon output ,however you want to measure it, is that makes it totally fair.

efficiency is a benefit of LED so if you do a watt for watt comparison and see how much par or ppf is produced then that's a fair comparison it doesn't matter if LeD is more efficient. If that's the case then it should easily show that LeD produces 30% more photons by wattage and the discussion can then be moved to fine tuning spectrums but that's a whole other conversation, and according to this study not as important as just increasing the amount if photons reaching your plants.
 

Johnny Lawrence

Well-Known Member
Dude the last two troll bait led threads where you even posted side by sides and the site had a good laugh at those multicoloured plants under your leds all wilty and looking kike they just wet a round with a beaver.

Thats where exactly, too many times it all led is better than hos i can prove it.

Sheezzzz give me some real retorts this is too easy and i get bored if your not going to be challenging.

So far ive made a lot of points but im just trolled on your technicalities.

Ya see the problem with leds, no reply but another claim :-)
Hahahahaha

LMAO

You fail so fucking hard. Hey, FYI - the whole entire forum is laughing at you.

What a fucking joke.
 

Chris Edward

Well-Known Member
First let me say I'm not here arguing anything, I'm participating in a discussion about light intensity being one of the most important aspects of our grows.

I didn't really think I was confused or didn't understand, but I thought maybe you had some info I didn't about this. You really didn't say anything just now I didn't know though.

I understand ppfd can be messed with which is why I specified the comparison tests would need to be done at a fixed height above the canopy.

The type of light source doesn't matter because wattage used is wattage used. Yes some lights produce more or less light with that wattage. That doesn't change the comparison, that is the proof in the pudding if you will.

The point of comparing lights by wattage used vs photon output ,however you want to measure it, is that makes it totally fair.

efficiency is a benefit of LED so if you do a watt for watt comparison and see how much par or ppf is produced then that's a fair comparison it doesn't matter if LeD is more efficient. If that's the case then it should easily show that LeD produces 30% more photons by wattage and the discussion can then be moved to fine tuning spectrums but that's a whole other conversation, and according to this study not as important as just increasing the amount if photons reaching your plants.
@Thundercat,
I see what you are saying and in "theory" you are right, but if it were that easy then the test would have already been done a long time ago.

But...

There are a lot of variables that effect both HID's and LED's, so it's not like you could just pull some random lights off the shelf and compare them.
The results would be useless.
You would have to compile a database of as many bulb and fixture combos and LED setups as you could get your hands on and then work out an average based on this information and that would require some serious cash.

Then there would also be the need for a longevity test, which in the case of HID would take 6 months, but in the case of LED's, depending on how much the chips are under powered, could take 10-15 years.
The owner of California Lightworks claims that the first light prototype they made, over 15 years ago hasn't dimmed enough to be noticeably measured and they run their LED's at something like 75% their potential current.

Then on top of all this, you would have to find people who were interested in doing the test, but have no vested interest in the results, otherwise there will be bias.

But I see what you are saying, pit a 600-1,000 watt HID against a 600-1,000 watt LED and then suss out the results...
If the HID fails because it is a power hog, then so be it.
If the LED fails because it just can't produce the same PPF, then so be it as well.
At least then we would have a definitive answer to all this nonsense and we could put this silly debate to rest.
I am with you on that.

But I have a feeling that no matter how much data you present, the die-hards will still cling to their preferred light, no matter what and the debate will continue to rage on...

That's all...
 
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hillbill

Well-Known Member
The definitive tests have been done over and over and side by side also. On YouTube, other forums and here. People seem to think COB and Board growers never used the sacred hps. We switched because they grow more and better herb.

More light per watt, superior spectrum and less heat and worry. Simple choice like radial tires or graphite rods or Goretex or contacts for sports.
 

Chris Edward

Well-Known Member
The definitive tests have been done over and over and side by side also. On YouTube, other forums and here. People seem to think COB and Board growers never used the sacred hps. We switched because they grow more and better herb.

More light per watt, superior spectrum and less heat and worry. Simple choice like radial tires or graphite rods or Goretex or contacts for sports.
@hillbill
I see what what you are saying, but I am talking about something more along the lines of like Consumer Reports, where not just a few lights are tested, but everything on the market.
And next year or at specific times of the year the list will get updated...

Something like that will require backing, more than likely private funding, like some sort of crowd funding so it can remain unbiased.

Plus, when it comes to YouTube videos, it is hard to recommend decent comparison videos because so many of the videos on YouTube are just trash...
 

hillbill

Well-Known Member
Lots of sifting required but it is a far far different LED world than 5 years ago. COB and Phosphor technologies have progressed to the point of making extremely reliable fixtures capable of producing incredible amounts of high quality white light, all while becoming widely affordable.
 
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