Ok so I found these articles in a deep rabbit hole dive. I’m no expert when it comes to lights but I have fallen for a few of these “gimmicks”. At the end of the linked article there is a few more white lie articles about LEDs.
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theyre doing some lies themselves… im guessing to sell their lies - i mean, lights.
for example, they say most of green light is not absorbed. while many might cite the mccree curve, the quantity is still more absorbed than reflected, specially under high intensity circumstances (like we grow cannabis under).
i prob sound like a parrot, but looking for info on this by Bugbee or DesignLight Consortium (independent light qualifier) is probably more reliable than getting your info from just another competitor in a market filled with incomplete info and disinformation, like the grow light market.
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Consider the source
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I only read the first article but, what is the issue? He seemed to just be stating the obvious, without explaining the specifics, such as how, although higher luminous efficacy often indicates superior performance, it doesn’t necessarily mean that the LED is the best fit for all application and, that other factors such as color quality, lifespan, and cost-effectivene should also be considered.
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I’ve been looking at that companies offerings for a while now for a 3x3, the 2 channel driver looks the treat.
The cost is not a ‘treat’…
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I’m a budget grower and I don’t see many people talking about Bestva, I Have their 100w and 200w pro versions in my 2x3, too much light for the space, the pair of them was under $300 and I absolutely love them. Been my go to ever since. I personally always over light my space that way I can always dim them.
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What? that’s like all the thing says… but for real. The real value i’m seeing is these UV/FR/IR diodes in there as well. Like. those 365nm and 395nm UV diodes don’t spec out well. same w/ the deep reds and IR’s. the efficiency is shit. but the effects are great.
I’m starting to feel like an expert on lights. I’ve had enough smaller ones to review, and got my Evo10 setup. drivers mounted outside the room. FloraFlex 730w covers the other side of the room.
I started with a 500w szhlux light. has uv/ir diodes. lm281. that thing produced constantly great plants. I see a lot of these other lights skipping out on the UV diodes. which just makes bigger buds with more reds. but doesn’t get the complex purple side the UVA produces. like. that was one of my deciding factors. Plus I have PAR meters and UV/FR meter. so I can see what kind of light these things give off, i can measure things.
Yeah. the Finnchy 250w and 125w had the hottest UV and FR didoes on the lights. They were some great lights.
I think mfgr’s cheap out on the UV diodes, and you lose a bit of quality without that UV light.
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Unpopular opinion:
Spectrum is not really a big deal. I’ve flowered under blue with excellent results.
Full spectrum is a myth perfect spectrum is a myth and pretty much anything reasonable will do the job.
I’m not going to argue that my reds are 7% redder than your reds.
To me having a light that’s pleasant for my eyes to look at is more important than perfect spectrum for ultimate photosynthesis.
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This 
Plants don’t receive a steady spectrum 100% of the time out in the real world so why force it on them indoors. I Suspect even if a light could provide an absolutely full spectrum of light you would need all other factors to be on point 100% of the time in order for the plant to cope with the increases in photosynthesis.
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I believe all advertisers can be guilty of white lies, that is why I do not use their words, but hunt for folks using the item, but not from influencers, or presenters, as they are just another form of advertisers, pushing white lies.
Been waiting for @Northern_Loki to post, I’m sure it will be better than the post I was going to make. 
Will come back later and see what he says.
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“Efficacy is the single most important spec of a grow light”
For a grow light, I don’t know of anyone who is saying that but it remains an important consideration to anyone paying attention. Key phrase they’ve stated “single most important spec”. The only source to that statement per the top Google search results is Kind LED.
Maybe for those in a large facility … power is expensive and likely a top line concern. I also doubt they’d ignore quantum efficiency or heat at that level when evaluating lifetime costs.
Here are some thoughts:
I prefer my power consumption for a fixture, for an equivalent amount of photons, to be cheaper … and cooler.
Take two equivalent fixtures. Both have the exact same photon output but one of these has less efficacy. The fixture with less efficacy will result in more power consumption and it will also generate more heat.
Top tier fixtures will be utilizing the most modern LEDs, within the last couple of generations, primarily to improve efficacy while reducing heat generation produced from the fixture. Theoretically, this means an increase in the cost of the LEDs but, conversely, a decrease in the size of the power supply required and the amount of heat dissipation.
Cut rate fixtures tend to choose older and less efficient LEDs because … they tend to be less expensive to purchase. Remember those Gull Winged LEDS? Those were horrible but they continued to be used, up until fairly recently, because they were old tech and dirt cheap.
Further, even for the most modern LED components, they are bin graded. Which means, during manufacturing, some of the LEDs produced are better than the other LEDs produced … from the same manufacturer. A premium is charged for these binned LEDs because they have better efficacy values.
Efficacy is a metric that some manufacturers, to this day, continue to hide or fudge. We’ve even caught certain manufacturer’s using counterfeit LEDs simply so that they could claim better efficacy numbers. This state of affair has improved, though, primarily because folk are testing and sharing real world results. I’d like to think we’ve influenced them to an extent.
Efficacy of the LEDs used to manufacture fixtures increases with time as semiconductor process and technology improves. Also note, efficacy in a purchased fixtures only decreases with time due to aging.
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UV LEDs are, relatively, very expensive. They also have a very short lifetime, are inefficient, and with output that degrades quickly. Industry is working to improve output and lifetime but it’s a difficult problem and is in the stone ages compared to modern White LEDs. It is also why some folk currently choose fluorescent UV bulbs as they are inexpensive and more efficient than UV LEDs. Same factors apply, cheaper UV LEDs will typically have less output and/or lifetimes.
Which also brings up another point of interest. Volume production. UV LEDs are produced at a much smaller scale than white LEDs.
The volume of LEDs produced is tremendous for white because it is used everywhere. So, we get cheaper LEDs because volume, we get improved efficacy because technology, we get reduced heat generation because efficacy.
UV LEDs are trailing behind our desires. Personally, I’d still use them though for the integrated aspect. Maybe not as a deciding factor.
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Seen Mammoth LED? They’re specifically including green led’s as they say at high ppfd, green is actually better absorbed then red or blue. Dunno how true any of this stuff is, but the results kinda speak for themselves i think 
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Some thoughts on the spectra ideas. This research is a bit old but probably recognizable. The McCree curve. McCree, et al in the 70’s evaluated the photosynthetic quantum efficiency over a broad spectra. Where it’s old is that the light intensities utilized were low relative to the what we think about today. There are real effects such as over saturation and plant photo-protection mechanisms that can not be seen from his research but has been shown in later research … usually with exceedingly high PPFD. I’d also expect that the ability for a plant to utilizes photons at varying intensities to be non-linear. That is, as intensity increases, the overall efficiency decreases. Maybe the curve stays the same but the plant begins slowing in it’s ability to produce chemical energy where some of that energy is shunted into a non-useable sink … such as heat. And, his experiments were not on Cannabis, per se. A modern version, perhaps at varying intensities, would be interesting. Most researchers still utilize McCree’s teachings. Knowing this, here is the McCree curve:
Relative Quantum Efficiency (RQE) indicates how efficient the plant is at photo-synthetically converting photon energy into chemical energy. This is normalized to 100%, e.g. relative to the highest point of quantum efficiency.
As a guide, here is the Bugbee breakdown of spectra of interest:
287-320nm : UVB
320-399nm : UVA
400-475nm : Violet-Blue
476-550nm : Cyan-Green
551-700nm : Green-Yellow-Red
701-850nm : Far Red-NearIR
or, an easier variant:
400-500nm : Blue
500-600nm : Green
600-700nm : Red
Note that this graph does not say anything about photo-morphology. Rather, efficiency of photosynthesis. Also this is different from efficacy being discussed.
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Excellent comment. The degradation of diodes within a narrow range wouldn’t show up so simply when taking PPFD readings either. Only an astute observer may notice a slight dip and begin to chase where it went. These ideas as they relate to light signaling are an important topic for hobbyists who make use of LED lighting. Many blessings and much love
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Right. You’d need a spectrometer for that (or, maybe some filters but good luck) which can be quite expensive and not always easy to use.
And, all LEDs are going to degrade over time. Some faster than others and depending on how much you stress them (heat being one factor).
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Totally agree, it would take an astute observer to even notice such things and then to consider the appropriate tools and resources needed to actually pinpoint the diodes and spectral ranges being degraded basically puts it out of reach from most anyone outside of professional settings. The rare hobbyist may have these tools and resources but it would certainly not be the majority.
I still recommend HID to hobbyists, I don’t necessarily go around putting LED’s down but think HID is a more ideal driver of indoor plant horticultural practices. At least as the primary source of photons that plants receive. It could also be because I’m older and the LED’s are the new kid on the block. The short board when everyone was surfing longboards. The thruster when it was all singles and twins. Heck, even the fin itself as before that there were just subtle humps and such carved into the wood.
So to say, like surfboards made for a variety of styles and waves, so too can light arrays be constructed and designed for a variety of plant types and growing styles across all types of different climates. Many blessings and much love
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You really don’t need such tools in practice, though. Being aware of what is going on, the advantages/disadvantages/pitfalls, is of primary significance when selecting different lighting technology.
Which can become a complicated. Maybe proportional to the level of OCD or expense. When, perhaps, 90% of the benefit to the plant is from just having more PPFD.
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My God does you peoples brains have that stuff bouncing around inside them like that all the time? All that knowledge gave me a headache just readin it. Impressed beyond words!
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