LED vs H.I.D

Boatguy said:

Sad that we are still entertaining threads with led vs hid..
It has been proven that led can produce more gpw than hid.
Why people are still trying to push hid anywhere outside of a greenhouse sized grow or other large scale thing is mind boggling. The benefits of led even have large scale growers making the switch.. Plants dont care about the artificial light source, and love the lack of issues associated with being outdoors

Click to expand...

People who are purchasing and consuming do not care about GPM they care about quality. HPS is better quality. I don't care what scientist and studies in labs have shown. I listen to those who smoke it and tell me which they like most and it is the HPS grown flower. I wish it wasn't true because I enjoy using LED's a lot. Mixed spectrum is where it is at best of both worlds.
Another note, those saying HPS cost more ect ect I did not find it true with 7 years running Leds I spent some years 5% more or 5% less not enough to matter. With Leds you have to run a lot more humidifiers vs HPS that uses more AC which also humidifies while cooling. Also heating in winters cost more with led. And that is with running both lights on at night so the heating period was during the warmer parts of the days.
Also Leds made strains I had ran for years take on avg 2 weeks longer to finish and wanted to keep pushing new hairs and I believe that is from the higher ppfd. Most Leds are too focused on higher ppfd when it stresses the plants too much. Less truly is more.

cage said:

If the Hortilux Super Blue really was the pinnacle of flowering quality, you'd still see them in use by winners of Emerald Cup or Spannabis. But most of them have gone LED, even the old-school breeders are switching over.

Most recent Cannabis Cup winners (2019–2024) increasingly use high-end full-spectrum LEDs

Some legacy winners from the 2010s did use CMH or HPS, often combined with heavy CO₂ and environmental control, but rarely MH or dual-arc bulbs like the Hortilux Super Blue.
Masonic Smoker, Compound Genetics, Jungle Boys, and Connected Cannabis Co. — known for top-tier flower — have either switched to LEDs or hybrid LED/CMH setups in recent years.

According to the 2023 State of the Cannabis Lighting Market report by Cannabis Business Times, LED lighting has become the predominant choice among commercial cannabis growers:

- 73% of commercial cultivators reported using LEDs for flowering in 2023, up from 15% in 2016.
- 62% of growers cited "crop quality" as the primary reason for adopting LED technology, surpassing considerations like yield (16%) and energy efficiency (12%).

DogHouse Supreme Cannabis, a five-time Dope Cup award winner, has transitioned to using Sunscape LED lighting systems. The cultivator reported significant benefits, including up to a 70% reduction in electricity usage and enhanced terpene production, particularly during the final two weeks of flowering .

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Thats odd because all the growers I know have either fully gone back to hps between 2024 and now or to mixed light because the quality just was not there with LEDs. They did not care what the lab results were they listen to customers. Only way to know what is best is by doing so not reading lab test sorry, it can be helpful in some ways but it doesn't and never will tell what is the real fire bud.

HazeIsMids said:

People who are purchasing and consuming do not care about GPM they care about quality. HPS is better quality. I don't care what scientist and studies in labs have shown. I listen to those who smoke it and tell me which they like most and it is the HPS grown flower. I wish it wasn't true because I enjoy using LED's a lot. Mixed spectrum is where it is at best of both worlds.
Another note, those saying HPS cost more ect ect I did not find it true with 7 years running Leds I spent some years 5% more or 5% less not enough to matter. With Leds you have to run a lot more humidifiers vs HPS that uses more AC which also humidifies while cooling. Also heating in winters cost more with led. And that is with running both lights on at night so the heating period was during the warmer parts of the days.
Also Leds made strains I had ran for years take on avg 2 weeks longer to finish and wanted to keep pushing new hairs and I believe that is from the higher ppfd. Most Leds are too focused on higher ppfd when it stresses the plants too much. Less truly is more.

Click to expand...

The idea that AC humidifies is factually not correct. Though it may regulate rh a bit upwards in some situations since lowering temps will make the air hold less absolute humidity the AC tends to draw out water from the air as it cools it; thats why you need that little drain/tank. Enjoy growing

Rocket Soul said:

The idea that AC humidifies is factually not correct. Though it may regulate rh a bit upwards in some situations since lowering temps will make the air hold less absolute humidity the AC tends to draw out water from the air as it cools it; thats why you need that little drain/tank. Enjoy growing

Click to expand...

24-25C AC drops RH by 5-10%
If you lower the temps even more, RH will become steady at what it was when you began

LEDs was unleashed on the world to do one thing only, destroy living tissues.
Plants and humans are alike, we both suffer from those lights
All of the tests being done on weed and other plants show they are no match for real noble gas/magnetic arc tech, which mimic the sun best for more than 50 years.

If your customers don't care and they like your LED bud and you save $$$ while doing it, good for you or them, but it wont change the reality of their specs or the tech itself from being harmful and lacking.

PTS.Genetics said:

24-25C AC drops RH by 5-10%
If you lower the temps even more, RH will become steady at what it was when you began

LEDs was unleashed on the world to do one thing only, destroy living tissues.
Plants and humans are alike, we both suffer from those lights
All of the tests being done on weed and other plants show they are no match for real noble gas/magnetic arc tech, which mimic the sun best for more than 50 years.

If your customers don't care and they like your LED bud and you save $$$ while doing it, good for you or them, but it wont change the reality of their specs or the tech itself from being harmful and lacking.

Click to expand...

I dont really know how to respond or what youre responding to; my comment was that AC dont humidifies, dont raise humidity. Just as you say it removes humidity from the air.

I have lots of sympathy for peeps having problems growing with leds, especially what you find on todays cookie cutter spectrum market. But the "leds unleashed" sounds very conspiranoia to me.

The "all the tests" without any source or reference is hard to take serious if you can wrap your head around that ive seen something different in tests of my own, both led vrs HPS and CMH and different leds vrs eachother with serious differences in spectrum. All i can assume is that the tests you talk about was not using what we use. Sadly almost all modern grow leds have a spectrum which i dont quite like the end quality of in comparison to various lights.
But ill happily grant you that some genetics do bad with leds, our mandarine kush was never really right under leds. Our amnesia haze was both yieldier, denser and better quality/smell than the HPS side in the same growspace, and environment was more geared towards the hps side then the led side in that side by side.

When it comes to testing; leds offer one thing that hps dont; the possibility to modify specific parts of the spectrum to see how it affect end quality. With HID you only have your base spectrum, or variants due to mixing of bulbs.
A lot of the spectrum design i did witht the lights ive tested i had one eye on the HPS spectrum - not in trying to recreate it but keeping in mind that HPS have certain nm balanced against eachother in specific bioreactive ranges which your standard cold white + red led dont have.
My best advice re leds that dont give you the results you want: way too much green and 660red, not enough wide coverage of the blue violet uv end.

I aldo admit that theres a subjective factor involved: terp levels % in is only part of the story, the other part is how it hits your own nose/lungs/mind.

"If your customers don't care and they like your LED bud and you save $$$ while doing it, good for you or them, but it wont change the reality of their specs or the tech itself from being harmful and lacking."

This is an unusually respectful way of talking, both in this age old discussion a d generally for online behaviour. I hope i dont sound to snarky and i want to extend the same invitation: grow buds with bulbs and enjoy.
Going with leds for us had somewhat to do with power savings (or not reaching our baby amp limit) but more to do with environment: it was just impossible to keep going with HPS as a light source due to temps and summers getting so hot that you couldnt cool down the space no matter how we tried, and AC was not an option unfortunately.
If youre ever forced to change tech then remember there is someone who made it work, youre welcome to hit me up.

All the best and many happy grows

Rocket Soul said:

The idea that AC humidifies is factually not correct. Though it may regulate rh a bit upwards in some situations since lowering temps will make the air hold less absolute humidity the AC tends to draw out water from the air as it cools it; thats why you need that little drain/tank. Enjoy growing

Click to expand...

your correct because what I meant was dehumidifies. Mistype sorry.

Thats what i meant, no disrespect
If you and your crowd are good with it, go with it, why not
Just know the facts, claiming leds are better than hids just shows what kind of joke people have bought into, again, no disrespect, use what you want, but dont claim its superior when you know its not.
I wont dig up a test or peer review anytime someone new to this bs wants, if you are really interested in this subject, research it.
Come back and tell me if what i said about other plants grown under leds were successful like HIDs or the sun.
Do your own research and draw conclusions.
And just because something sounds "conspiracy like" to you, doesn't mean its not valid, it just means you are better at deflection with high words that were made for this purpose, dismiss opinions and people.
Now you know why i never take you seriously Rocket Soul, you are a led salesman, never took the time to study the tech you sell, busy calling people's opinions and facts for that matter, conspiracy.
Good luck for all indeed, they are gonna need it.

PTS.Genetics said:

Thats what i meant, no disrespect
If you and your crowd are good with it, go with it, why not
Just know the facts, claiming leds are better than hids just shows what kind of joke people have bought into, again, no disrespect, use what you want, but dont claim its superior when you know its not.
I wont dig up a test or peer review anytime someone new to this bs wants, if you are really interested in this subject, research it.
Come back and tell me if what i said about other plants grown under leds were successful like HIDs or the sun.
Do your own research and draw conclusions.
And just because something sounds "conspiracy like" to you, doesn't mean its not valid, it just means you are better at deflection with high words that were made for this purpose, dismiss opinions and people.
Now you know why i never take you seriously Rocket Soul, you are a led salesman, never took the time to study the tech you sell, busy calling people's opinions and facts for that matter, conspiracy.
Good luck for all indeed, they are gonna need it.

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kingrow1?

Same condescending tone either way.

PTS.Genetics said:

Thats what i meant, no disrespect
If you and your crowd are good with it, go with it, why not
Just know the facts, claiming leds are better than hids just shows what kind of joke people have bought into, again, no disrespect, use what you want, but dont claim its superior when you know its not.
I wont dig up a test or peer review anytime someone new to this bs wants, if you are really interested in this subject, research it.
Come back and tell me if what i said about other plants grown under leds were successful like HIDs or the sun.
Do your own research and draw conclusions.
And just because something sounds "conspiracy like" to you, doesn't mean its not valid, it just means you are better at deflection with high words that were made for this purpose, dismiss opinions and people.
Now you know why i never take you seriously Rocket Soul, you are a led salesman, never took the time to study the tech you sell, busy calling people's opinions and facts for that matter, conspiracy.
Good luck for all indeed, they are gonna need it.

Click to expand...

Links to LED Vs HPS controlled studies:

Trial A: Photosynthetic Performance and Potency of Cannabis sativa L. Grown under LED and HPS Illumination link: https://www.scirp.org/journal/paperinformation?paperid=108091

Trial B: Light Quality Impacts Vertical Growth Rate, Phytochemical Yield and Cannabinoid Production Efficiency in Cannabis sativa Link: https://www.mdpi.com/2223-7747/11/21/2982

Trial C: The Effect of Light Spectrum on the Morphology and Cannabinoid Content of Cannabis sativa L. Link: https://karger.com/mca/article/1/1/19/189037/The-Effect-of-Light-Spectrum-on-the-Morphology-and

Trial D: Cannabis lighting: Decreasing blue photon fraction increases yield but efficacy is more important for cost effective production of cannabinoids Link here: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0248988

Trial E: Influence of Light Spectra on the Production of Cannabinoids Link here: https://www.sciencedirect.com/science/article/abs/pii/S0926669021001151

Phytoplankton said:

Links to LED Vs HPS controlled studies:

Trial A: Photosynthetic Performance and Potency of Cannabis sativa L. Grown under LED and HPS Illumination link: https://www.scirp.org/journal/paperinformation?paperid=108091

Trial B: Light Quality Impacts Vertical Growth Rate, Phytochemical Yield and Cannabinoid Production Efficiency in Cannabis sativa Link: https://www.mdpi.com/2223-7747/11/21/2982

Trial C: The Effect of Light Spectrum on the Morphology and Cannabinoid Content of Cannabis sativa L. Link: https://karger.com/mca/article/1/1/19/189037/The-Effect-of-Light-Spectrum-on-the-Morphology-and

Trial D: Cannabis lighting: Decreasing blue photon fraction increases yield but efficacy is more important for cost effective production of cannabinoids Link here: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0248988

Trial E: Influence of Light Spectra on the Production of Cannabinoids Link here: https://www.sciencedirect.com/science/article/abs/pii/S0926669021001151

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Great posting this, PP, i dont think ive seen these before except for D.

PTS.Genetics said:

Thats what i meant, no disrespect
If you and your crowd are good with it, go with it, why not
Just know the facts, claiming leds are better than hids just shows what kind of joke people have bought into, again, no disrespect, use what you want, but dont claim its superior when you know its not.
I wont dig up a test or peer review anytime someone new to this bs wants, if you are really interested in this subject, research it.
Come back and tell me if what i said about other plants grown under leds were successful like HIDs or the sun.
Do your own research and draw conclusions.
And just because something sounds "conspiracy like" to you, doesn't mean its not valid, it just means you are better at deflection with high words that were made for this purpose, dismiss opinions and people.
Now you know why i never take you seriously Rocket Soul, you are a led salesman, never took the time to study the tech you sell, busy calling people's opinions and facts for that matter, conspiracy.
Good luck for all indeed, they are gonna need it.

Click to expand...

It’s not a “claim” when it’s supported by data. LEDs being more efficient, cooler-running, and capable of delivering targeted spectrums isn’t up for debate anymore, it’s just reality. The real joke is pretending we accidentally created the perfect grow light for cannabis with 90s-era street lamps.

What I find predictable is that whenever people can't actually back up their stance with peer-reviewed research or real-world results, they default to “do your own research.” It's a way to avoid accountability for weak arguments. If you have real data or controlled comparisons to support your beliefs, please share them. If not, don't expect others to carry the burden of proving you wrong when you haven’t proven yourself right.

You're clearly emotionally attached to HID lighting, and that’s fine. But your identity is so tied to it that any criticism feels like a personal attack on you. That’s why you’re not engaging with the facts, you’re defending your ego.

LED tech didn’t surpass HID because of marketing or “the herd.” It surpassed it because it actually got better, higher umol/J efficiency, lower heat load, full spectrum tuning, longer lifespan, and lower operating costs. If that threatens your worldview, that’s on you, not on the people moving forward.

And calling someone a “salesman” for pointing out facts just shows you're out of ammo. You don’t have to like LEDs, but pretending they aren't superior today is just denial.

I kind of stopped reading when they said they had the HPS, 4 FEET Away.
Given they didnt state, or I didnt read far enough. They didnt specify if they were using 1150w DE HPS like a Gavita ect, or a 1000w Hortilux HPS.

Given that, I run the DE 1150w Gavita at 36in-40in, and a 1000w Hortilux at as close as 15in-18in, which is blasting the crap out of them vs 4ft away. And the DE we use, is a FOOT closer than what they tested with, from what part I read.

Also the Very First Advertised, For Growing Weed Grow Light was??

In 1977-78, and it came from the Navy Sub Program. Nuclear subs, would often have no contact, for 6 months, or more, so they used 1000w Metal Halide to grow fresh veggies. Tomatoes for one, which supplies an abundance of vitamins, and minerals. Think Scurvy. 1 good sized tomato, can supply 40% of RDA for Vitamin C.
The bulb was advertised in High Times, and it was so fragile, they would not warranty it for shipping. So if it arrived damaged? Tough luck.
6 months later they came out with the Supernova, and also an 8 x 5 gallon-9 with res, container Hydro Unit called the Octagarden. And Yes, I had both. Never used the Hydro part, but used the containers.

So HID grow lights predate 90s street lights by at least 13 years. And 70s vs 90s. 3 decades difference.

I never switched to HPS, until Hortilux took the HPS, and added some Blue in it. HPS grown under those old HPS, with no blue, were horrendous, IMHO. Though, they are 165,000 Lumens!!!!! So one would often combine 100,000 -110,00 lumen Halide, with a 165,000 HPS, back in the 80s, is what I did.. Plants need Blue.

And while LED may spread light a bit better, in a 4 x 4 area, a 1000w Hortilux HPS, supplies enough power to grow any strain to its genetic potential.

And as far as spectrum A Hortilux Blue has a spectrum of 280nm-2000nm+. Same for the MMS 6000k Halide. No LED can anywhere near that.

I myself find the combination of a 1000w Hortilux HPS, and 2x Solacure Flower Power Bulbs, to be the best combination, for me, and I own an 680w Mammoth, which is IMO one of the better LED.

Im bettin at 15 inches, and using a 1000w Hortilux HPS, a Raptor Reflector, very few are pushing any more umol than I am, in a 4 x 4 regardless of light source.

jimihendrix1 said:

I kind of stopped reading when they said they had the HPS, 4 FEET Away.
Given they didnt state, or I didnt read far enough. They didnt specify if they were using 1150w DE HPS like a Gavita ect, or a 1000w Hortilux HPS.

Given that, I run the DE 1150w Gavita at 36in-40in, and a 1000w Hortilux at as close as 15in-18in, which is blasting the crap out of them vs 4ft away. And the DE we use, is a FOOT closer than what they tested with, from what part I read.

Click to expand...

I enjoyed skimming the links and kept my mind open to the science. I saw that also about the 4 ft distance. That is standard for a warehouse grow with 50 or more 1000w cheap hps bulbs. Not sure what size the grow was that was using that distance.
A lot of these studies are heavy in references and the growers aren't likely to be equally as good at both types of lighting.
IMO both grow excellent weed when dialed in, LED does it more efficiently.

HazeIsMids said:

People who are purchasing and consuming do not care about GPM they care about quality. HPS is better quality. I don't care what scientist and studies in labs have shown. I listen to those who smoke it and tell me which they like most and it is the HPS grown flower. I wish it wasn't true because I enjoy using LED's a lot. Mixed spectrum is where it is at best of both worlds.
Another note, those saying HPS cost more ect ect I did not find it true with 7 years running Leds I spent some years 5% more or 5% less not enough to matter. With Leds you have to run a lot more humidifiers vs HPS that uses more AC which also humidifies while cooling. Also heating in winters cost more with led. And that is with running both lights on at night so the heating period was during the warmer parts of the days.
Also Leds made strains I had ran for years take on avg 2 weeks longer to finish and wanted to keep pushing new hairs and I believe that is from the higher ppfd. Most Leds are too focused on higher ppfd when it stresses the plants too much. Less truly is more.

Click to expand...

AC doesn't humidify, it dehumidifies.

1212ham said:

AC doesn't humidify, it dehumidifies.

Click to expand...

yup I addressed my mistype in the replies I am very well informed that AC's dehumidify autocorrect can mess up anyone's post sorry bout that!

Kushash said:

I enjoyed skimming the links and kept my mind open to the science. I saw that also about the 4 ft distance. That is standard for a warehouse grow with 50 or more 1000w cheap hps bulbs. Not sure what size the grow was that was using that distance.
A lot of these studies are heavy in references and the growers aren't likely to be equally as good at both types of lighting.
IMO both grow excellent weed when dialed in, LED does it more efficiently.

Click to expand...

Recommended distance, from Gavita, for an 1150w DE HPS, is 36in-40 inches from canopy.

Im going to start using my UVA/B according to this study. This is the most detailed, published study Ive seen on, UVA/B supplementation on Marijuana.

They used multiple ratios/times/w/sq/m ect, and determined that only ONE WAY to use UVA/B was found to be of benefit, and it increased 3 terpenes, BIG TIME.
Linalool being increased by 29%.
Limonene increased 25%
Myrcene 22%,
This seems to be pretty big shit, especially when you combine the %%%s of all 3. Thats an astounding 76% increase on the 3 combined chemicals!!!!!

A study published in the journal Frontiers in Plant Science by researchers from Humboldt-Universität zu Berlin examines how different UV spectra and intensities impact cannabis growth, yield, and secondary metabolite composition.

Study: UV Light Intensity and Spectrum Influence Cannabis Growth …​

themarijuanaherald.com/2025/01/study-uv-light-intensity-and-spectrum-influence-c…


The study tested three UV light spectra at five intensity levels, analyzing their effects on photomorphogenesis, inflorescence yield, and the chemical profile of cannabis. While none of the UV treatments altered cannabinoid concentrations, significant changes were observed in terpene profiles under certain conditions.

Notably, the UV treatment labeled L3_1, which emitted UVA:B at a 99:1 ratio and an intensity of 1.81 W/m², increased concentrations of key terpenes. Compared to the control group without UV exposure, linalool rose by 29%, limonene by 25%, and myrcene by 22%. This treatment maintained consistent yield and cannabinoid levels, making it the most practical option for commercial cannabis cultivation.

Additionally, UV exposure affected growth and leaf morphology. Higher UVA levels increased leaf area, while elevated UVB levels resulted in smaller leaves. However, only the L3_1 treatment was deemed viable for large-scale cultivation due to its ability to enhance terpene profiles without compromising plant yield or cannabinoid content.

The findings suggest that selective use of UV light could help optimize terpene production in cannabis, offering potential benefits for both growers and consumers.

Below is the study’s full abstract. The full text of the study can be found here.

The raising economic importance of cannabis arouses interest in positively influencing the secondary plant constituents through external stimuli. One potential possibility to enhance the secondary metabolite profile is the use of UV light. In this study, the influence of spectral UV quality at different intensity levels on photomorphogenesis, growth, inflorescence yield, and secondary metabolite composition was investigated. Three UV spectra with five different intensities were considered: L1 (UVA:B = 67:33, 4.2 W/m2), L2 (UVA:B = 94:6, 4.99 W/m2), L3_1 (UVA:B = 99:1, 1.81 W/m2), L3_2 (UVA:B = 99:1, 4.12 W/m2) and L3_3 (UVA:B = 99:1, 8.36 W/m2). None of the investigated UV treatments altered the cannabinoid profile. Regarding the terpenes investigated, light variant L3_1 was able to positively influence the terpene profile. Especially linalool (+29%), limonene (+25%) and myrcene (+22%) showed an increase, compared to the control group without UV treatment. Growth and leaf morphology also showed significant changes compared to the control. While a high UVA share increased the leaf area, a higher UVB share led to a smaller leaf area. Of the UV sources examined, only L3_1 with 1.81 W/m2 and a radiation dose of 117.3 kJ m2 d-1 is suitable for practical use in commercial cannabis cultivation. The terpene concentration for this group was in part significantly increased with constant yield and cannabinoid concentration.

Click to expand...

jimihendrix1 said:

And as far as spectrum A Hortilux Blue has a spectrum of 280nm-2000nm+. Same for the MMS 6000k Halide. No LED can anywhere near that.

Click to expand...

LEDs can produce NIR(near infrared) just fine.
People just don't want them in their grow lights,
since it's just extra heat.

jimihendrix1 said:

Im bettin at 15 inches, and using a 1000w Hortilux HPS, a Raptor Reflector, very few are pushing any more umol than I am, in a 4 x 4 regardless of light source.

Click to expand...

Plenty of LED fixtures that put out more PPF,
but most don't need as much since their lights are not hanging from the greenhouse roof all the way up.

jimihendrix1 said:

I kind of stopped reading when they said they had the HPS, 4 FEET Away.
Given they didnt state, or I didnt read far enough. They didnt specify if they were using 1150w DE HPS like a Gavita ect, or a 1000w Hortilux HPS.

Given that, I run the DE 1150w Gavita at 36in-40in, and a 1000w Hortilux at as close as 15in-18in, which is blasting the crap out of them vs 4ft away. And the DE we use, is a FOOT closer than what they tested with, from what part I read.

Also the Very First Advertised, For Growing Weed Grow Light was??

In 1977-78, and it came from the Navy Sub Program. Nuclear subs, would often have no contact, for 6 months, or more, so they used 1000w Metal Halide to grow fresh veggies. Tomatoes for one, which supplies an abundance of vitamins, and minerals. Think Scurvy. 1 good sized tomato, can supply 40% of RDA for Vitamin C.
The bulb was advertised in High Times, and it was so fragile, they would not warranty it for shipping. So if it arrived damaged? Tough luck.
6 months later they came out with the Supernova, and also an 8 x 5 gallon-9 with res, container Hydro Unit called the Octagarden. And Yes, I had both. Never used the Hydro part, but used the containers.

So HID grow lights predate 90s street lights by at least 13 years. And 70s vs 90s. 3 decades difference.

I never switched to HPS, until Hortilux took the HPS, and added some Blue in it. HPS grown under those old HPS, with no blue, were horrendous, IMHO. Though, they are 165,000 Lumens!!!!! So one would often combine 100,000 -110,00 lumen Halide, with a 165,000 HPS, back in the 80s, is what I did.. Plants need Blue.

And while LED may spread light a bit better, in a 4 x 4 area, a 1000w Hortilux HPS, supplies enough power to grow any strain to its genetic potential.

And as far as spectrum A Hortilux Blue has a spectrum of 280nm-2000nm+. Same for the MMS 6000k Halide. No LED can anywhere near that.

I myself find the combination of a 1000w Hortilux HPS, and 2x Solacure Flower Power Bulbs, to be the best combination, for me, and I own an 680w Mammoth, which is IMO one of the better LED.

Im bettin at 15 inches, and using a 1000w Hortilux HPS, a Raptor Reflector, very few are pushing any more umol than I am, in a 4 x 4 regardless of light source.

Click to expand...

Where did you get information that the navy grew tomatoes in submarines with HIDs in 77-78?

I cant find any documentation of it. What i can find is information from the mid 2010s that the Navy started growing hydroponics under LEDs.

jimihendrix1 said:

Im going to start using my UVA/B according to this study. This is the most detailed, published study Ive seen on, UVA/B supplementation on Marijuana.

They used multiple ratios/times/w/sq/m ect, and determined that only ONE WAY to use UVA/B was found to be of benefit, and it increased 3 terpenes, BIG TIME.
Linalool being increased by 29%.
Limonene increased 25%
Myrcene 22%,
This seems to be pretty big shit, especially when you combine the %%%s of all 3. Thats an astounding 76% increase on the 3 combined chemicals!!!!!

A study published in the journal Frontiers in Plant Science by researchers from Humboldt-Universität zu Berlin examines how different UV spectra and intensities impact cannabis growth, yield, and secondary metabolite composition.

Study: UV Light Intensity and Spectrum Influence Cannabis Growth …​

themarijuanaherald.com/2025/01/study-uv-light-intensity-and-spectrum-influence-c…


The study tested three UV light spectra at five intensity levels, analyzing their effects on photomorphogenesis, inflorescence yield, and the chemical profile of cannabis. While none of the UV treatments altered cannabinoid concentrations, significant changes were observed in terpene profiles under certain conditions.

Notably, the UV treatment labeled L3_1, which emitted UVA:B at a 99:1 ratio and an intensity of 1.81 W/m², increased concentrations of key terpenes. Compared to the control group without UV exposure, linalool rose by 29%, limonene by 25%, and myrcene by 22%. This treatment maintained consistent yield and cannabinoid levels, making it the most practical option for commercial cannabis cultivation.

Additionally, UV exposure affected growth and leaf morphology. Higher UVA levels increased leaf area, while elevated UVB levels resulted in smaller leaves. However, only the L3_1 treatment was deemed viable for large-scale cultivation due to its ability to enhance terpene profiles without compromising plant yield or cannabinoid content.

The findings suggest that selective use of UV light could help optimize terpene production in cannabis, offering potential benefits for both growers and consumers.

Below is the study’s full abstract. The full text of the study can be found here.

Click to expand...

This is the second time you've shared this, how exactly do you plan on hitting 99:1 UVA:B at 1.81w/m squared? Id love to hear how you're going to achieve the exact ratio so I can apply it myself.

waytoofaded said:

It’s not a “claim” when it’s supported by data. LEDs being more efficient, cooler-running, and capable of delivering targeted spectrums isn’t up for debate anymore, it’s just reality. The real joke is pretending we accidentally created the perfect grow light for cannabis with 90s-era street lamps.

Click to expand...

Huh ?
The data says no led can come close to HID spectrum wise
So it spread light better, and make more light from each watt but like we said before, that light is no match in spectrum to HIDs, never will be.

waytoofaded said:

What I find predictable is that whenever people can't actually back up their stance with peer-reviewed research or real-world results, they default to “do your own research.” It's a way to avoid accountability for weak arguments. If you have real data or controlled comparisons to support your beliefs, please share them. If not, don't expect others to carry the burden of proving you wrong when you haven’t proven yourself right.

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Im not your teacher or father bud, grow up, you are clearly not interested enough in facts or truth, if you were, you would have researched this subject on your own, you didnt, just shows you lack wisdom and knowledge on the subject.

waytoofaded said:

You're clearly emotionally attached to HID lighting, and that’s fine. But your identity is so tied to it that any criticism feels like a personal attack on you. That’s why you’re not engaging with the facts, you’re defending your ego.

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Lol
Emotionally attached
Clearly you are bad at addressing facts, but good at addressing authors
Take a rain check buddy, go check the facts again, you are too confused.

waytoofaded said:

LED tech didn’t surpass HID because of marketing or “the herd.” It surpassed it because it actually got better, higher umol/J efficiency, lower heat load, full spectrum tuning, longer lifespan, and lower operating costs. If that threatens your worldview, that’s on you, not on the people moving forward.

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Lol x 2
Leds spectrum is no where near hids, sorry mate, you have no idea what you are talking about, unfortunately.
Higher lumen output, yes, in lame spectrum.
Lower heat... Is that an advantage? Ked growers struggle to keep rh and temps in range, its known, they end up spending more on AC haha
Keep thinking your moving forward lol

waytoofaded said:

And calling someone a “salesman” for pointing out facts just shows you're out of ammo. You don’t have to like LEDs, but pretending they aren't superior today is just denial.

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NO friend, calling someone what he is, is facts, not lack of ammo.
And again, if you researched the facts, you would have known they are far from being superior, hell, even CFL are better.
LEDs emitt dangerous radiation that kills living tissues in all living things.
No matter what advantages this tech holds, this downside is enough for it to be thrown in the trash.

To me, personally, its perfect that so much people growing with leds, just makes my buds sell quicker and for a much better price as they compare them to the shit led bud they buy all the time and much prefer the ol trusted hids product.