3500k vs 4000k vs 5000k ?

Sativied

Well-Known Member
yes but why are the light sources that "bring out the colors" like cobs and 93-cri LEC beating hps across the board on yield as well?
I think you missed the point there.

Cuz more photons at same watts? :bigjoint:
Nope.

One of the main reasons is because they use space more efficiently lol. Ask Rhaz about yield-ppfd relationship, different discussion.

Professor Bugbe at Utah state University who is one of the foremost experts on plant lighting has conducted tests saying that photon output is the main reason for growth and there is no propf that a higher blue spectrum increases vegitstive growth or node spacing in plants.
Appeal to authority without quote... you probably took that way out of context. I'm not going to debate the effect of blue, that would be too silly. Anyone can confirm this easily based on the many books and scientifc papers as well as the many factual results.

You kids don't seem to understand the value and importance of led as grow light. Not to get you high but to continue to feed the population.

Blue for photomorphogenesis, red for assimilation.

https://www.wageningenur.nl/en/newsarticle/Steering-compactnes-with-blue-light.htm
Just one example, large trials with additional blue light is already used on hundreds of thousands of meters of plants to replace grow regulators. You know, more efficient growing rather than producing photons efficienctly.

Couple of more:
https://www.wageningenur.nl/en/newsarticle/LED-lighting-in-greenhouse-horticulture.htm
Photosynthesis at different wavelengths
http://www.tuinbouw.nl/sites/default/files/documenten/20120413 GTB-1151_LR.PDF

Just a few examples of the endless amount of proper research and science I can tap in to. ANY farmer here using led knows far and far more about what they grow than any of you.

Those trials and real world results involve more than a few professors, doctors and all unbiased experts.

Indeed, but it seems that photons matter more than spectrum acording to Prof Bugbee at Utah state.
You don't have a unlimited amount of ppfd. Do you use npk 1-1-1 too? Do you use solely blue light because it's way more efficient to produce.... Lol...
 

Sativied

Well-Known Member
"Why some stems are red: cauline anthocyanins shield photosystem II against high light stress"
http://jxb.oxfordjournals.org/content/61/10/2707.full

http://link.springer.com/article/10.1007/s11099-011-0042-y
"Anthocyanins act as a sunscreen, protecting the chloroplasts from high light intensities. This shading effect causes a lower photosynthetic CO2 assimilation in red plants compared to green plants, but a higher quantum efficiency of photosystem II (PSII). Anthocyanins contribute to photoprotection, compensating for lower xanthophyll content in red plants"

(The "but" conflicts with some other research, but hey... Intellectual honesty...)

Why some stems are red: cauline anthocyanins shield photosystem II against high light stress
http://jxb.oxfordjournals.org/content/61/10/2707.long
The photoprotective effect appears to be a widespread phenomenon.

Just a few examples... I can go on and on as you all know lol
"Nature's Swiss Army Knife: The Diverse Protective Roles of Anthocyanins in Leaves"
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1082902/

"https://www.researchgate.net/publication/275836722_Leaf_anthocyanin_photosynthetic_light-use_efficiency_and_ecophysiology_of_the_South_African_succulent_Anacampseros_rufescens_Anacampserotaceae"

I got nearly the whole set in my closet. Red, pink and purple. Some examples

image.jpeg image.jpeg image.jpeg image.jpeg

Those (PCK) are genetically high in anthocyanin. I have not been able to compare except for using high blue mh and hps and one thing is obvious, lowest yielding plants I had. Which can be explained by many reasons, above all being heavily inbred landrace, but one fact stands, they would do so much better under blurple with the high amount of red.

Everyone knows they can get purple when cold right? That's anthocyanin for very similar reasons.

I don't breed for red or purple but high anthocyanin. Why? Because I can. There are obviously up and downsides, but one thing is undeniable, they are pretty as fuck.
 

Yodaweed

Well-Known Member
Straight 4000k flowers smaller, denser, frostiest nugs Ime. It's better to mix 3000k and 4000k. The 3000k seems to elongate the nugs while the 4000ks keep the density and frost up. Both spectrums work awesome on their own, but the mix has worked best for me.


Sent from my iPhone using Tapatalk
That's because 3k has more far red in the spectrum, the 4k will make more stout plants.
 

churchhaze

Well-Known Member
The plant effectively filters out the blue/green to protect chlorophyll and prevent overloading the system, by changing the absorption spectrum, correcting your cob choice mistake and the poor match to the action spectrum as a result, reducing the amount of photons actually used for photosynthesis.
Talk to @RM3. :dunce: You're preaching to the choir here. Notice how until recently, everyone was using 3000k, which does NOT have too much blue. Your buddy RM3 uses WAY WAY WAY too much blue and I've been saying this for months.

(@Rev.thenatural = @RM3 )
 
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churchhaze

Well-Known Member
To make things worse, RM3's ultrablue T5 tubes cost 32 dollars a piece! More than the price of a vero29. So if you hate the concept of people thinking they can buy epeen, go give him hell. Otherwise you show contradictions which shows your obvious bias against LED users.

 
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Yodaweed

Well-Known Member
To make things worse, RM3's ultrablue T5 tubes cost 32 dollars a piece! More than the price of a vero29. So if you hate the concept of people thinking they can buy epeen, go give him hell. Otherwise you show contradictions which shows your obvious bias against LED users.

That guy is pretty funny to talk to, he is convinced pouring boiling water on his plants is good.
 

tstick

Well-Known Member
I think you missed the point there.


Nope.

One of the main reasons is because they use space more efficiently lol. Ask Rhaz about yield-ppfd relationship, different discussion.

Appeal to authority without quote... you probably took that way out of context. I'm not going to debate the effect of blue, that would be too silly. Anyone can confirm this easily based on the many books and scientifc papers as well as the many factual results.

You kids don't seem to understand the value and importance of led as grow light. Not to get you high but to continue to feed the population.

Blue for photomorphogenesis, red for assimilation.

https://www.wageningenur.nl/en/newsarticle/Steering-compactnes-with-blue-light.htm
Just one example, large trials with additional blue light is already used on hundreds of thousands of meters of plants to replace grow regulators. You know, more efficient growing rather than producing photons efficienctly.

Couple of more:
https://www.wageningenur.nl/en/newsarticle/LED-lighting-in-greenhouse-horticulture.htm
Photosynthesis at different wavelengths
http://www.tuinbouw.nl/sites/default/files/documenten/20120413 GTB-1151_LR.PDF

Just a few examples of the endless amount of proper research and science I can tap in to. ANY farmer here using led knows far and far more about what they grow than any of you.

Those trials and real world results involve more than a few professors, doctors and all unbiased experts.


You don't have a unlimited amount of ppfd. Do you use npk 1-1-1 too? Do you use solely blue light because it's way more efficient to produce.... Lol...
-excellent video! Thanks for your contributions! I always enjoy reading your posts.
 

Sativied

Well-Known Member
Ok one more:

"Under blue and green light we found the most outspoken effects: plants grown under green light were tallest with the largest leaf area whereas plants grown under blue light were shortest, had their stomates widest open, had low leaf temperatures and the lowest total plant weight. "
https://www.wageningenur.nl/en/newsarticle/LED-lighting-in-greenhouse-horticulture.htm



Similar tests are performed for hundreds of varieties. As I mentioned before, led grow light is not about pushing lum eff everytime you can. That's what led itself is about. The potential for led grow light is much and much larger than just the inherent, inevitably increasing, lum/eff where this forum is mainly about.

Perhaps it's more obvious now why cree has a xpe assortement specifically for horticulture and why white cobs alone are rare compared to more efficient (for the plant) led grow lights. The companies selling led grow light in the cannabis industry are doing pretty much the same thing as some of the guys here, I'd frankly put more trust some sellers here for at least trying out their lights themselves.

@alesh: https://www.fluence.science/physiospec/
It's hard to say if they just picked up some stuff from the web but at least they go further than pushing the more efficient white cobs with wrong spectrum. I don't know much about them, I think compared to them diy is the way to go. I think I have answered your other question with the above posts too.

Do you guys have something like dragon's den specifically for inventions? We have "the best idea of NL". Many inventions are dismissed because they are nothing more than combining/applying inventions from others... there is a huge difference between hooking up cobs and designing a grow light.


And while I am at it:
https://community.greentech.nl/crops/b/knowledge-inspiration/posts/why-diffuse-light-works (see my led corn bulb red herring... Err, thread about light direction...as well as several comments about the directional top lighting led approach leading to photoinhibition at the top...)

@Rhaz:

Ppfd still doesn't quite cut it. It's on horizontal plane, and not as I mentioned here (or maybe dutch forum) about uniformity across a 3D plant. In any case, ppf can be pushed higher across the entire plant. Enter the stage: intra/inter/side lighting.

If max efficiency at the plant and max yield from a space was the intention, you guys would be thinking very differently. I'm thinking rockhard 3-4 feet tall colas. Fuck horizontal, fuck vertical, let's go 3D. There is much more to efficiency of light at the target than just the efficiency at the light source and as I've been saying from the start your bibled efficiency numbers cannot be translated 1-1 to gpw. In practice it can be rather exact, but that's from many more factors.
 

churchhaze

Well-Known Member
As I mentioned before, led grow light is not about pushing lum eff everytime you can
You keep using that term... :dunce:

Even if you mean luminous efficacy, you're still wrong. The point is to push efficiency, not luminous efficacy or luminous efficiency. You take the concept of straw man to the extreme.

Not luminous efficacy... Not luminous efficiency... Just efficiency. Because you keep getting this wrong, I keep having to assume you don't understand what you're talking about. Please at least get on the same level before you continue to make your long winded posts.

Your writing reminds me of the menus in chinese restaurants that use 3 different spellings for the same word all right next to each other in hopes one of them are correct.
 
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Atulip

Well-Known Member
Ever just walk into a thread and say.. I'm too high for this shit?

Considering we've been growing some fine weed under 20cri hps that peaks at what 560-600nm? Cutting watts at the wall(and the biggest cost of indoor growing) without sacrificing quality is most people's goal.



What's the QER of 90cri 3000k anyway? I know the LER is lower, so the efficiency is there...
 

churchhaze

Well-Known Member
@Sativied, we're still waiting to see your blurple grow. Show us what you can do by chasing the 660nm peak and with low yellow/green. Show us what happens when you realize the hard way that photosynthesis of algae in a petri dish is different than growing buds on tall weed plants.

Don't just talk. Show. At least @PSUAGRO. is actually putting his love of 660nm to the test. Go look at his results under a spectrum heavy in 660nm and light in yellow and green. Compare it to his new grow that's mostly white cobs with only some 660nm supplementation.
 

Sativied

Well-Known Member
Considering we've been growing some fine weed under 20cri hps that peaks at what 560-600nm?
That's just a fallacy I responded to already. If you are merely building a light to beat hps, you can do so with 80 and 90 cri. Handy to get a rough idea how much cob light you need to replace hps, but choosing a lower cri led because hps is much lower anyway is a fallacy.

I'm sure some people clearly are too high but I don't think it's cannabis...

Cutting watts at the wall(and the biggest cost of indoor growing) without sacrificing quality is most people's goal.
Which you can do with 80 and 90 cri in any case. And again, where does that end. At some point your energy bill will be low. Lowering low with 5% isn't going to make a difference.

At some point it will be, already is, low enough to fill the max ppf with the best and most useful wavelengths. When you do that with a suboptimal spectrum, you effectively will sacrifice quality and quantity.

Absense of evidence does not equate to evidence of absense...
 

Sativied

Well-Known Member
Courtesy of @alesh

Total QER...
View attachment 3696385


Strictly 400-700nm QER...

View attachment 3696383


total...
80cri=4.87...90cri=4.91

400-700
80cri=4.66...90cri=4.51
For those who don't see what happened there. The values for the 90cri were reduced because text book par knowledge involves "par range is 400-700.

Essentially dismissing the value of FarRed, while I'm sure gg's aware of Pfr and the emmerson effect. (Honestly don't know how much the latter applies, fact remains that light is not useless and trading some blue for Fr would be wise).

In any case, it does not refute the main point, you can still make up for the difference by either running the same cobs harder or add cobs to maintain efficiency.

Honestly, I would gladly pay a few bucks a month for slightly less efficiency and a slighlty higher cost upfront just to have my plants look so beautiful. Am I the only one who got a hardon seeing neverenuf's grow... Nearly perfect colors for photos and diagnosing.

One of main arguments from led folk is that the investement in led can be earned back in x years by energy savings. Is the suboptimal spectrum really worth it for people to make that x years minus 10%... No, do the math, convert to factual energy cost savings. If you're going to use a light that long, build a proper one from the start. It will hold its value longer too.
 

Greengenes707

Well-Known Member
I hate 400-700 as "PAR" I always prefer everything the light source has to offer...UV or IR sides of it.

PAR by definition is anything that drives photosynthesis. With that said...all the way up to 725nm has over 25% RQE. It seems pretty silly to only use 400-700nm to me...plants feel that way too, whether for slight growth, or photomorphis and in turn gaining surface area to have more photosynthesis via more reactions, not faster rate of photosynthesis(efficiency).

The question is always are the gains worth the losses. Do you get a net gain...? Experimenting is and has been going on. It will come to light eventually, but right now there is nothing definitive within the parameters we are working with.
 

churchhaze

Well-Known Member
But what if the 80cri spectrum is actually better? You're making an educated guess that the 90cri spectrum will produce a better yield, better buds, or both.

You're the only one here claiming to know what the perfect spectrum is. Everyone else posting here knows for the most part that they're just guessing and trying what they think is the best.

@Sativied, you sound exactly like the LED fans of 2003. They were so excited that they would be cutting out wasteful colors like yellow and green and concluded that they could grow with traffic signals.
 

churchhaze

Well-Known Member
I hate 400-700 as "PAR" I always prefer everything the light source has to offer...UV or IR sides of it.

PAR by definition is anything that drives photosynthesis. With that said...all the way up to 725nm has over 25% RQE. It seems pretty silly to only use 400-700nm to me...plants feel that way too, whether for slight growth, or photomorphis and in turn gaining surface area to have more photosynthesis via more reactions, not faster rate of photosynthesis(efficiency).

The question is always are the gains worth the losses. Do you get a net gain...? Experimenting is and has been going on. It will come to light eventually, but right now there is nothing definitive within the parameters we are working with.
Think of it like band pass filters. The -3db points are where the bandwidth frequencies officially start and end, but there's obviously a lot of frequency range affected that's not included in the bandwidth.

It's an approximation that's done all the time. Same thing is used for output pattern angle. Obviously some light gets out past the 120 degree cone, but 120 is where it becomes "negligible". (Edit: i guess this one is a bad example considering light outside 120 degrees is counted in the total output) There's really no other way to pick cutoff points without doing it arbitrarily, and the scientific consensus seemed to have been 400-700.

edit again: I'm not saying it's the best.. but there's really no reason to discount it either. It is what it is. It would be harder to do the math against a weighted curve like mccree rather than just gating it with the PAR range.
 

JorgeGonzales

Well-Known Member
Think of it like band pass filters. The -3db points are where the bandwidth frequencies officially start and end, but there's obviously a lot of frequency range affected that's not included in the bandwidth.

It's an approximation that's done all the time. Same thing is used for output pattern angle. Obviously some light gets out past the 120 degree cone, but 120 is where it becomes "negligible". (Edit: i guess this one is a bad example considering light outside 120 degrees is counted in the total output) There's really no other way to pick cutoff points without doing it arbitrarily, and the scientific consensus seemed to have been 400-700.
I dunno man, how many dB an octave are we talking here? I don't think that analogy works at all. Strawman! Ad hominem! Argument from Graham Bell!

Yeah.
 
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