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LED and BUD QUALITY
- Thread starter Tropical Sun
- Start date
greyfader
Well-known member
the bulbs are 14 watt 120 volt walmart household bulbs with the diffusers cut off. lately i found even cheaper ones on amazon. look for the world famous "Great Eagle" brand. they all last a very long time.Sure it comes down to a complex interaction of genetic and environmental factors. Genes determine the maximum possible expression of a quantitative trait such as thc and terpene content, bud mass, body height, IQ or whatever, and environmental factors determine how much of that potential is actually realized. The light source does not just determine spectrum but has an impact on other environmental factors such as ambient temperature, leaf surface temperature, transpiration rate, nutrient uptake, metabolization and therefore thc/ terpene synthesis rate, and thc/ terpene evaporation rate and they all affect quality.
I can also imagine that some terpenes are being synthesized at a higher rate at different temperatures and definitely they volatitilize at different temps and that might be a reason for some phenotypes seeming to perform better under LED, some better under HPS, because the terpenes etc that are characteristic for their smell and taste are synthesized at a higher rate and/or retained better (though that could be compensated by taking measures tonincrease/decrease temps, then).
My LED grows are significantly cooler on the average than my HPS grows were and I like that. My anecdotal experience says the optimum temps are around 22 celsius but then I never had the chance to do side by sides which is one reason why I am so keen to see those.
Plus the fact I can reach g/w ratios similar to or better than a 600w HPS grow with 20 watt screw ins, scalable from 20w and North of that.
Are these screw ins in your pic Osram Superstar e27 20.5 watts by chance? If so, how many runs do you use them.before you replace them?
And by incandescent you mean those regular bulbs that we used before LED and fluorescents and in which ratio do you use them? Sorry if you have already gone into this earlier.
Btw what you're saying about starving thebplants to "enhance" thc and terpenes, if you mean by that increase their production during the last days/ weeks of flower, that would definitely have an effect on the taste of the end product? The more terpenes the less harsh/ plant matter -like the smoke would be?
i just run them until i see a weak one in the row, pull it out, shitcan it, and put in a new one. a slow, continuous changeover. i don't see a noticeable gradual degradation so it is probably occurring slowly and slightly.
some of these bulbs are 3 years old.
i don't have the gear to measure the relative strength of the LED's compared to incandescent.
i do know the watt ratio. during the red light phase i had 924 watts of 2700k LED and 150 watts of tungsten incandescent in the form of 6 25 watt appliance bulbs spread evenly over the canopy. which was a 4x4.
next time i intend to up the ratio of incandescent slightly.
sorry, i forgot to mention that in dr bernstein's literature there is a paper showing starving nitrogen enhances cannabinoid and terpene synthesis. i don't have it right in front of me but there's a reference to it in the bibliography of the 90 min. podcast.
Rocket Soul
Well-known member
I think its based on this paper (sadly paywalled
) its the only thing ive found regarding this. Fair enough it may give somewhat better photosynthetic efficiency at high intensity (most of the famous macree action spectrum is based on low to medium light intensity). Ive never seen the rest of the paper so cant really speak about it. What makes me think green=less quality is the not very well known Green response in horticulture and plant morphology. Its resumed as
- lower transpiration/stomata closure
- inhibition of blue response
- more fibery or support role tissue growth.
Im sorry, cant find the link for it but should be goolgable with "green response horticulture".
The best way to try to wrap your head around it: where in the plant do you have the highest relative green content? Intracannopy or anywhere lower in the cannopy. Red and blue are all very easily absorbed by the leaves so when you get into the cannopy the remaining spectrum is very heavy in green and far red.
What type of growth does the plant favor in the lower cannopy? Support growth, stem and branches, which are more fibery. My reasoning is that this doesnt favor a strong flower response; the plant is expending energy in building fiber. And i believe its the very same reason why 4k based leds make very dense (as in weight/volume, not the same as hard bud) bud, but slightly uninteresting in the flavour/high department.
Caveat: this is my theories and understanding, from looking at bud grown with different light sources (weve done HPS/CMH/multitude of different leds) i dont have hard evidence in the way of papers. Its not been very well studied in cannabis but the green response has been described in traditional horticulture. Bugbee seems to think green has no morphological effect but i havent allways been so impressed with his experimental designs. But anyone i show our "special spectrum" bud next to straight 3000k 80cri (or 4k+660) prefer the special bud, you can even smell the difference, especially in our Rainbow cut.
greyfader
Well-known member
like the wild prowling leo's!
yes, there's now literature showing that green can drive photosynthesis nearly as well as red but not until high light levels are reached. the ratio of efficiency goes up with the intensity.
editing to add that @Rocket Soul beat me to it but green has greater penetration in plant tissue than blue or red and the sun has a huge portion in the PAR range.
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Rocket Soul
Well-known member
You really should look into Bridgelux Vesta strips if youre going for 5000k/2700k - forget about changing all those bulbs, its as easy as just connecting/disconnecting a wago. They are also relatively cheap, about 10 for a 25w strip. 90cri aswell, which means extra red content and the red peak shifted from around 600nm to around 630nm.
It also allows you to run both channels at the same time for a better efficiency "full cycle" spectrum of around 3700K. And it opens up the DIY rabbithole...
greyfader
Well-known member
shame!It would be interesting to see comparative lab results on the same clone grown under top bin leds and top of the line hps. So far that does seem to be missing from this thread. My money is on them not being different enough for 99% of people to notice. I have a sour clone drying that I did this with, one led one cmh, but I am not in a legal place so can’t get proper lab results but will share my observations once the cmh stuff is dry.
**Just realised this isn't the HPS vs LED thread...
I Care
Well-known member
All the haters are the same.
Platinum info
I prefer the term haters, I feel it is politically correct… sensitive times man.
Platinum info
I think its based on this paper (sadly paywalled
What makes me think green=less quality is the not very well known Green response in horticulture and plant morphology. Its resumed as
- lower transpiration/stomata closure
- inhibition of blue response
- more fibery or support role tissue growth.
Im sorry, cant find the link for it but should be goolgable with "green response horticulture".
The best way to try to wrap your head around it: where in the plant do you have the highest relative green content? Intracannopy or anywhere lower in the cannopy. Red and blue are all very easily absorbed by the leaves so when you get into the cannopy the remaining spectrum is very heavy in green and far red.
What type of growth does the plant favor in the lower cannopy? Support growth, stem and branches, which are more fibery. My reasoning is that this doesnt favor a strong flower response; the plant is expending energy in building fiber. And i believe its the very same reason why 4k based leds make very dense (as in weight/volume, not the same as hard bud) bud, but slightly uninteresting in the flavour/high department.
Caveat: this is my theories and understanding, from looking at bud grown with different light sources (weve done HPS/CMH/multitude of different leds) i dont have hard evidence in the way of papers. Its not been very well studied in cannabis but the green response has been described in traditional horticulture. Bugbee seems to think green has no morphological effect but i havent allways been so impressed with his experimental designs. But anyone i show our "special spectrum" bud next to straight 3000k 80cri (or 4k+660) prefer the special bud, you can even smell the difference, especially in our Rainbow cut.
greyfader
Well-known member
yes, i've been jumping down "DIY rabbitholes" for quite some time. i'll get around to it when i get things going a little smoother in my new place.
i do know how to use wagos and i can solder pretty good so i'm running out of excuses.
but what i'm really interested in is learning how to build lights that run off a DC power supply. where i live i've got fairly predictable wind and sun.
talk about freedom!
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greyfader
Well-known member
hater's lose!
Rocket Soul
Well-known member
When you get to it my dms are always open
As far as solar directly to led: i looked into it a bit, think you need to have some device, maybe even just some batteries, to stabilize voltage. And then some kind of current regulation. To be honest for your first build just use regular drivers for ease. Then try to get a solar solution. If you find the right driver you would be able to run of dc anyways.
I thought wind would be AC, its turbine based?
Rocket Soul
Well-known member
Thx
Its theories really, as always we never have the full picture nor from science papers nor from observational "bro science". But if you combine and correlate the both, and actually take the time to grow with different spectrums and look at others grow you can draw conclusions which get closer and closer.
Hoping to build some boards based on this as ive recently found all parts and components i need in a nice package. Just need the cashflow now which seems to always be whats eluding me...
greyfader
Well-known member
i would use a battery bank, you would have to for constant voltage.When you get to it my dms are always open
As far as solar directly to led: i looked into it a bit, think you need to have some device, maybe even just some batteries, to stabilize voltage. And then some kind of current regulation. To be honest for your first build just use regular drivers for ease. Then try to get a solar solution. If you find the right driver you would be able to run of dc anyways.
I thought wind would be AC, its turbine based?
wind turbines can generate either ac or dc. the reason we all run on AC current today is that it travels well over long distances. DC works great for short distances. lots of sailboats use small dc wind turbines for charging battery systems off which they run lights, refrigerators, ac's. almost all AC household appliances can be had as DC devices as well.
I Care
Well-known member
This is a good crowd man. I bought a toolbox off a guy once. He said Covid… he sold out of RVs and he and the wife were already considering retirement. Well that man gave me a quote that will stick with me forever. “..just tryin’ to make chicken salad out of chicken shit” pretty much been my moniker since
Rocket Soul
Well-known member
"Not my circus, not my monkeys" have been a mantra keeping me sane lately...
Rocket Soul
Well-known member
Wheres these boards youre talking of? 90cri?
I recently harvested 2 clones of ThaiA5, one indoors grown under LED and one outdoors grown under intense sub tropical sun (27S). I'm very fussy about quality and in all honesty there's barely a difference between the two. The outdoor bud structure was better and maybe the terps were slightly stronger under the sun. If the sun grown is stronger by a couple of percent THC you can barely notice. It might translate to needing 5 hits instead of 4. No big deal.
Similarly, years ago when I transitioned from HPS to LED I saw no reduction in quality. At the time I was growing an NL2 clone. If anything it seemed better under LED, but again the change was minor.
Genetics is everything (almost) and differences under various lighting is pretty minor in my experience. Having said that if I had the choice I would choose sun, but living in an illegal area indoors under LED is much less stress and the quality is there.
Similarly, years ago when I transitioned from HPS to LED I saw no reduction in quality. At the time I was growing an NL2 clone. If anything it seemed better under LED, but again the change was minor.
Genetics is everything (almost) and differences under various lighting is pretty minor in my experience. Having said that if I had the choice I would choose sun, but living in an illegal area indoors under LED is much less stress and the quality is there.
I Care
Well-known member
eBay, private seller selling boards and kits of what they have left in stock.
Edit: it’s listed as a “sun board”, can probably find the seller like this
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D
Deleted member 539861
I grow with Osram Superstar 20.5 Watt screw in LEDs with the bulb removed, I can't find the data sheet right now but it has plenty of green and I can't complain, neither about low yields nor not getting high enough. I have also read that above a certain light saturation additional green light will lead to more additional photosynhetic activity than additonal red or blue.
