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

[hillbill]

I have Walmart 24” under cabinet led strip lights that put out 100 lumens per watt at 5000k I use in shop room. I am sure they would do fine growing our favorite plant. Just that people building lights specifically for growing use the most efficient diodes or COBs or Boards they can.

I would think fo moms and clones these would be great and at $11.97 less than $1 per watt and can be daisy chained.

Using some of these would just be a hoot.

I don't work for Walmart.

 

[Kingrow1]

And waste a lot of energy.

Not for plant receptors and then again photosynthesis which is photon related... Hmmm could you expand on this or are you only using blanket suggestions today.

The lack of understanding of hps spectrum is the reason we can stupidly hype the led one, on paper great... on a website of good growers it hasnt made the grade, cmh and hps can grow just as much watt for watt even t5 will give led a run for its money.

Not sure some have grown long enough to know hype and hysteria from real world and science, why do led users cite such easy troll bait as ppfd and claim superiority without even understanding why ppfd was made as a scale.

 

[hillbill]

Ode to Kinggrow 1

 

[Thundercat]

Perhaps if someone or some company would make an LED spectrum Light EXACTLY THE SAME as the HPS spectrum .......
View attachment 4282965
That would be interesting.

Instead of targeting the hps spectrum I think we should target the sun. Everyone agrees that the sun grows better weed then anything else right? Well then let's aim to make our lights as close to the sun as possible..... Full spectrum with uv for a good tan!

Step two intensity, and this is where lots of people that run LED go a stray I think. The sun puts an average of 1500 ppfd onto a canopy over the day. Most LED growers I see turn their lights down for efficiency and only run a few hundred ppfd. That isn't how you replicate the sun....

 

[Kingrow1]

Instead of targeting the hps spectrum I think we should target the sun. Everyone agrees that the sun grows better weed then anything else right? Well then let's aim to make our lights as close to the sun as possible..... Full spectrum with uv for a good tan!

Step two intensity, and this is where lots of people that run LED go a stray I think. The sun puts an average of 1500 ppfd onto a canopy over the day. Most LED growers I see turn their lights down for efficiency and only run a few hundred ppfd. That isn't how you replicate the sun....

I have seen enough tests trying to replicate the suns UV but still outdoor plants win in that area which goes to show it is very complicated and above our meager hobby

 

[Coalcat]

I never said I knew the best spectrum...the study said spectrum didn’t matter.

I said that leds produce photons the most efficiently. Which seems to matter the most. If you actually care about spectrum make the leds do whatever spectrum you want.

I actually grow with a 1000w and a small 400w hps. I don’t have any leds. The cost payback doesn’t make sense for me yet.

I thought the study was interesting an illuminating.

And when you know the most efficient spectrum maybe publish dont troll since were all waiting for this science you seem to know but as yet the world havent worked out and is one darn complex subject.

You didnt think owning an led and copy paste made you in the know about science did you.... It dont

 

[Thundercat]

I never said I knew the best spectrum...the study said spectrum didn’t matter.

I said that leds produce photons the most efficiently. Which seems to matter the most. If you actually care about spectrum make the leds do whatever spectrum you want.

I actually grow with a 1000w and a small 400w hps. I don’t have any leds. The cost payback doesn’t make sense for me yet.

I thought the study was interesting an illuminating.

Hehe sounds like we are in the same boat. I thought the study was a great read, and it seemed fairly un-biased which can't be said for many other similar comparisons . I'm all for improving light intensity over my canopy. my 1k hps does great over a 4x4, but I think 1k of LED spread more evenly over/around my 4x4 would totally improve yields and quality. It's just not in my budget yet.

 

[Midnight Warrior]

Wow! All LEDs finished 5 days sooner than HPS! 8% less time so you can flower a new batch 5 days sooner! And smoking it almost a week sooner! Not to mention the energy savings. Win! Win! Win!

Very very interesting study for led users. Basically amount of light is more important than specific spectrums. Commercial broad spectrum leds (strips/3000k boards)are better than tuned (burple). Finally leds are about 40% more efficient at doing this than hps.


https://poseidon01.ssrn.com/delivery.php?ID=872119091124113027026103000122093087049073070064025021111113076102071094101118124000120032062006006027002112107105105071026004000029026049019118078084024092091011034006054124064097004065096123067073028002112079070124096107086115103082104101070125086&EXT=pdf

No examples of light sources are given. Reads like a college student's essay, not from a university study.

 

[Johnny Lawrence]

Yer less wattage is more managable for you, eitber that or you sucked at hps (likelty scenario).

Just cause you did better dosent mean they are better, easily debunked lol

I've been growing successfully under HIDs for longer than you. You're a scrub.

I'm not even gonna get into it, because at this point, anybody that is a reg at this forum understands that you're a clown.

Cry more about LEDs, Nancy. WTF?

 

[Chris Edward]

I have a whole closet full of 600 and 1000 watt Hortilux bulbs. Nothing but "clutter" for me. I will most likely never use an HPS again.
LED technology has hit the point of far superiority to HID in most circumstances. It will only get better and better.
Like comparing modern tv to the old "consoles". Led will always have their "doubters" for a while longer.

Bah humbug, LED's are a fad!
Just like "The YouTube" and "The Interweb"...

LOL...

 

[Chris Edward]

I read everything you wrote and intresting stuff but the matter still exists that hps growers yeild as much as any light watt for watt from rthe wall or the whole site led grows would stand out as far better in everyway and that simply has never been the case here.

Im glad Phillips know the perfect spectrum.... anytime they want to tell us an exact formula so we can dismiss the rest and focus on one spectrum only per species... I mean ive waited years for that science if you have that....

Hps old.... yes, broke.... you calling us growers lights here shite...insult much cause we have always stood our ground and your tests, mainly led growers need us hps growers to teach you science lest you view our measky few hundred watts like super heaters, be more inclined if most led growers werent so arrogant and flipant to science basico 101....

If i changed it would be cmh, single point light rules your flimsy wattage problems... Next youll be quotting me ppfd like your god ugggghhh.

So ya i like your info just disagre with your led market hype, your led future is some wet dream also and jacking your orices past us hobbyists who see very little loss of money when we spread the cosy not a $1000 upfront for thirty year old diode tech older than the dawn of man mr stonage guy....your flogging very old tech, ideaa far too costly till now but still costly

@Kingrow1,

You seem upset…

I never said HPS is shit.
Basically what I said is that it is a tried and true method that many feel “isn't broken, so why fix it."
Essentially I said people are stuck in their ways…
HPS is wasteful, but effective.

LED’s have changed a lot in just the past few years…
When I was a kid and the first “high output" LED’s came out, their outputs were dim candles compared to the flood lights that now exist. And these current LED’s use similar voltage and current.
LED tech is constantly evolving and it’s always getting better.
The same however cannot be said for HID lights, despite a few percent gains here and there, the format has reached it’s limits.
Not unless something way out of left field comes into play like another LEP type arrangement.

Just like the vacuum tube had to move over for the transistor and people resisted, so too will be the case with HID and LED’s, eventually.

As soon as I can find that PDF that has a bit of light recipe info I will be more than happy to share it.
Phillips on the other hand only shares limited light recipe info when you purchase a shit load of lights and more than likely require you pay into some subscription program (I haven’t looked into it that deeply).

If I come off as arrogant, I am sorry.
That isn’t my intention.
I am sorry you feel that way.
If it is something I have specifically said (rather than “LED users” in general), please tell me so I will know how to not sound like a prick in the future…

The point of RIU seems to be about learning from each other so we can all be better growers; it’s not cutting each other and slinging hate, that’s what politics is for.


Talk to you later

 

[Chris Edward]

Listen...it all comes down to efficiency. Leds just make photons more efficiently than other methods. Even in your house 100w bulbs replaced with 23w cfl replaced w 14w led. And if you want to argue spectrum you can really make leds do anything...broad or narrow. You could make the spectrum exactly the same as a hps if you want. It all comes down to light cost vs electric cost vs payback. You can’t argue against the efficiency.

@Coalcat,
Preach!!!

 

[Chris Edward]

I find it odd that people are more concerned about the color of diodes than actually growing cannabis. It's like some think the only way you can grow good weed is with the latest LED technology. I can set a plant outside and grow good weed. This is getting crazy stupid with the LED crap. People grow great weed without LED's.

YOU DON'T NEED THE LATEST LED LIGHTING TO GROW GOOD WEED!

Half of the posts about LED's are shill accounts from LED manufacturers or people selling LED's.

Only stoned pot growers are gullible enough to fall for all the nonsense.

@xtsho,

Normally I agree with you, but not this time.

The HID vs LED question is the cannabis growers version of Mac or PC…

We all have our reasons and we have all convinced ourselves that these are good reasons and we will fight for those reasons dammit!!!

Here’s my reason…
Where I live if I put any plant outside it will either dry up, freeze, or be eaten because the climate is so harsh.
I would love to grow outdoors, but very few plants can grow here outside.

So I have to grow indoors.
I also live in an area where electricity is cheap (thankfully) but if they see a spike in your power they will come snooping…
So, if I can use an LED light that uses no more wattage than an electric heater or a couple of box fans, then no one is going to notice anything and that's the way I like it.

When people set up their grow rooms they spend a small fortune on heat and scent extraction, but seem to pay so little attention to electricity spikes, which in my book is just as important.

So for me, using LEDS is less about having the newest gadget to impress a bunch of my stoner friends with and more about NOT having a bunch of fuzz ramming in my door just because I decided to grow my own seizure and anti-anxiety medication.

Plus I like building things, so for me it's a win-win…

If I used HID, I would probably make the bulbs…lol

 

[Chris Edward]

Here's that PDF I have going on about that talks a little bit about Light Recipes.

Just to prove my point about how light recipe information is now being guarded, a few years ago this PDF was all over the Internet, now there are basically two ways to get it.
01. Join a research paper database, which requires an institution email address for approval.
02. Purchase it.

ResearchGate:
https://www.researchgate.net/publication/274075124_Leaf_Shape_Growth_and_Antioxidant_Phenolic_Compounds_of_Two_Lettuce_Cultivars_Grown_under_Various_Combinations_of_Blue_and_Red_Light-emitting_Diodes

The 2013 study was updated in 2015 and this is selling for $40 on SpringerLink.
https://link.springer.com/article/10.1007/s13580-015-1064-3

All the new study includes is data on green light which we already know has no real effect.

 

[Chris Edward]

Can anyone suggest a video hosting site where the signup doesn't require having to give personal information?

I have two videos I would like to share and RIU doesn't accept mp4 format and they are both over 10mb...

They are only a few minutes each.
They are excerpts from a British TV show called "Food Unwrapped" which is a show that does some basic surface investigation on food production, nothing too deep.

One video is a mini tour of Philips light recipe lab and the other is about an herb producer who uses spectrum to help the herbs deal with transportation stress and shelf life.

There's no technical data, but it is nice to see this sort of thing in a

 

[Chris Edward]

Here's a video for you COB heads out there...
With the misconceptions out there, this made me laugh...
I hope you get a chuckle from this too...

 

[hillbill]

These COBs and Boards are not your parents' LEDs.

 

[Chris Edward]

These COBs and Boards are not your parents' LEDs.

I love Big Clive...

 

[Chris Edward]

These COBs and Boards are not your parents' LEDs.

I love Big Clive...

 

[Kingrow1]

@Kingrow1,

You seem upset…

I never said HPS is shit.
Basically what I said is that it is a tried and true method that many feel “isn't broken, so why fix it."
Essentially I said people are stuck in their ways…
HPS is wasteful, but effective.

LED’s have changed a lot in just the past few years…
When I was a kid and the first “high output" LED’s came out, their outputs were dim candles compared to the flood lights that now exist. And these current LED’s use similar voltage and current.
LED tech is constantly evolving and it’s always getting better.
The same however cannot be said for HID lights, despite a few percent gains here and there, the format has reached it’s limits.
Not unless something way out of left field comes into play like another LEP type arrangement.

Just like the vacuum tube had to move over for the transistor and people resisted, so too will be the case with HID and LED’s, eventually.

As soon as I can find that PDF that has a bit of light recipe info I will be more than happy to share it.
Phillips on the other hand only shares limited light recipe info when you purchase a shit load of lights and more than likely require you pay into some subscription program (I haven’t looked into it that deeply).

If I come off as arrogant, I am sorry.
That isn’t my intention.
I am sorry you feel that way.
If it is something I have specifically said (rather than “LED users” in general), please tell me so I will know how to not sound like a prick in the future…

The point of RIU seems to be about learning from each other so we can all be better growers; it’s not cutting each other and slinging hate, that’s what politics is for.


Talk to you later

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