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LED and BUD QUALITY

Ca++

Well-known member
There are many UVB CFL's around. Most are 5 or 10% but the 12% tends to suppress the uva output a bit more. In ratio terms.
Try to mount horizontally, as it's difficult to reflect. Many papers delve into exotic metal mixes and layering surfaces. They tend to fall back on aluminium, with about 50% reflectivity that rapidly drops with surface contamination.


These kind of things are known as smart cobs, or driverless leds.
iu

The little chips are over-driven in every example I have seen. They are thermally reactive though, so back off on the power to attain the right temperature. In use, a 50w chip might start off at 50w but will drop quite a lot. Let me see..


I grew with some of these next ones, that are driven a little differently. They do make the 50w rated.

Unfortunately, when we see these in floodlights, in our stores, the efficiency stated ranges from 80-100 lumens per watt.

Ultimately, we are buying 50w chips that are 50w if we can recognise them. Giving us 4000 lumens for about $3. Plus the real cost, the heatsink. This, as a package, compares favourably with an e27 domestic lamp in outlay. Only the smart cob uses 50% more power, and you have to make it.

I got involved as I wanted a project. I had my lights looking out through a window cut in some ducting. It was more elegant than it sounds. Honest. Then again when I wanted a spot frequency. That is where these champion. You can specify colours. Beware, testing of the burples has seen numbers like 30 lumens per watt. It's for experimental use. Not viable plant lighting. Many of the designs are very old in our terms.

The last couple of years, these smart chips have been paired with Samsungs on bigger boards. Again the heatsink stops us buying them. With the smart chip efficiency really eating into the light units efficiency. Making a Mars a better option for most. Here is a complete unit, just to see one https://www.aliexpress.com/item/2255800112355797.html





Altitude doesn't just see more UV. The whole spectrum of colours is tipped. As we move from the sun, light attenuation is proportionate to wavelength. The seasonal disorders in people are due to lower blue levels. Down here, the red is getting through better. Up there, the white balance is better, as there is less attenuation of the green, and even less of the blue. For this reason, the better weed at altitude observations shouldn't be thought of as uv. Though it's a sign.
What we have seen is light ratio research where the red and blue rations are looked at. The result that neither should be far ahead of the other. With red able to take a greater lead, but shouldn't be more than 60% of the spectrum, if we don't want to see bleaching at even moderate light levels. These tests tell a story along with altitude. Our plants like a good white balance.
We don't have good white balance in our lights, though some of seen higher CRI as better than more umol. One of the goals to date, has been making the most useful light for the least electricity. Red is easier to make, so LEDs have been leaning heavily on red production to get them umol/j numbers higher. This works until we start using amounts of light on our high value crops, that other crops couldn't expend. As we push, we see the problems with poor white balance. Remember a few years back, we were all burple. Then white mixes. Now we are white with red and blue mixes. Plot out our direction. The very latest research has me about to swap out my panels for one's without extra reds. After my last swap was to get better reds. Crazy. Though the 301 evo isn't for us I don't think. As it moves away from a good white balance. With it's eyes set on leafy greens. It has low red levels that some 660s won't address in terms of even spectral output.
I have one thorn in my side. Our microgrows section. The comparisons thread. People liked warm white over cool white. I suspect the cool whites used red doping that wasn't as red as that in the warms. That is if could see the spectrum of each, we wouldn't just see less of the same red, but actually a shift of the red peak towards a shorter wavelength. It's the only way my mental image of whats happening can work. Which is an image of the sun being a good measure to replicate, as plants evolved to use it. Though I don't buy into the UV story, which I have run on 3 occasions. A 4th I put a plant under just UV-C, no other lighting. They can see it. I just haven't found it useful. Actually... I have not run uv-b since going LED. Now I just read the reports of the big players, which is the best thing about legalisation. Though some things you still have to do yourself.
 

Three Berries

Active member
^^^^ Those are the type of COBs I was using in the end. 100W wired directly with 120v. I screwed them to a big heat sink with a 3" fan on the top.

Those slim black ones I had but they burnt up. They need a fan on them. Scrapped them all.
 

Ca++

Well-known member
^^^^ Those are the type of COBs I was using in the end. 100W wired directly with 120v. I screwed them to a big heat sink with a 3" fan on the top.

Those slim black ones I had but they burnt up. They need a fan on them. Scrapped them all.
Very hot.. I keep them as emergency spares still, but ran them without the lens fitted. First thing Clive noticed was the heat radiation. Letting it out was useful. Though in my app I was extracting both past and through them. At that time I had nobody I wanted to show, so no pics. However..
1staircooled.jpg

This did nothing for bud quality, but did show me LED was viable. And cold.
 

JKD

Well-known member
Veteran
With the Fohse Pleiades you could potentially run it with HIDs - have the HIDs run through something like a Gavita or Dimluxx master controller that will auto dim them at a temperature set point. The Pleiades has ‘light harvesting’ as it’s designed as a greenhouse supplemental, when your HIDs dim it should brighten, but dim itself when the HIDs brighten.
 

Cerathule

Well-known member
@Cerathule "THC content increased from 25 to 32% (Lydon et al., 1987), suggesting that 19 -THC was a UV-B photo-protectant"

thank you for this link, this saves me a lot of time experimenting.

i have used a 1500 watt 4000k football stadium mh light in a geodesic dome lined with reflectix. one of these with 5 horti 1k's and i noticed a large increase in visible trich coverage on a strain that i was very familiar with but i had no way to quantify chemically at the time.

this bulb came with uv warnings.

now i need to find a few screw-in uvb leds.

this thread is turning into a useful tool.

has anyone looked at the fohse A3i yet? it looks like the most state of the art light out there. a lot of options.
Here's the full study, this one is really controversial. Bugbee completely denies it, and there are some newer studies finding no benefits of UVB, too.
Lydon tested 2 genetics but only 1 responded positively. That was a Colombian landrace used to harsh high altitude sunlight and high ppfd. Chances are medical strains suffer too much from genetic losses via generations of indoor cultivation. It's a good read, even Lydon speculates alot about his inconclusive results.
Many growers report positive experiences with UVB or A, but can't deny Bugbee as he's such an authority on that field.
Daily effective UVB dose.png
 

Attachments

  • UVB radiation effects on photosynthesis, growth and cannabinoid production of two Cannabis Sat...pdf
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Ca++

Well-known member
Oh wow and that didn't kill the plant?!
The plant grew to the lamp, with strange characteristics. Somewhat like reveg, or pure green experiments. Where the plant knows where the radiation is coming from, but has no real idea what to do. Unfortunately the experiment only lasted a few days. The soft tissue around my eyes swelled up from extended exposure, so I couldn't see at all. My flatmate ended the grow, and had to feed me instead.

Might be a lesson in there somewhere.
 

Ca++

Well-known member
Here's the full study, this one is really controversial. Bugbee completely denies it, and there are some newer studies finding no benefits of UVB, too.
Lydon tested 2 genetics but only 1 responded positively. That was a Colombian landrace used to harsh high altitude sunlight and high ppfd. Chances are medical strains suffer too much from genetic losses via generations of indoor cultivation. It's a good read, even Lydon speculates alot about his inconclusive results.
Many growers report positive experiences with UVB or A, but can't deny Bugbee as he's such an authority on that field.
View attachment 18741698
I can't see the PDF. However if they used the UV to restrict plant growth, then the thc per gram would increase. It's not thc per plant in that case though. It's not indicative of a gain
 

JKD

Well-known member
Veteran
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Ca++

Well-known member
Time lapse of one forming might be useful. As a secretion, that shape is interesting. My zits and blackheads never look like that
 

Ca++

Well-known member
A red photon carries 1.8ev (electron volts) and a blue carries 3.1ev
This is why two reds make a blue, and blue takes more energy to make.
Any light with more blue, has a lower ppf/w.
This doesn't help marketing.

The UV discussion revolves around plant protection. Someone posted 19-thc is a uvb absorbent. Overall, a coat of resin is diminishing the light on our buds through shading. Implications for pruning techniques, perhaps.

Someone spoke of a German forum last year. They were adding violet. Right where blue becomes UV. I didn't see the thread, but it's interesting.

I'm feeling favourable towards more blue. Though it can't go to 40% of the spectrum as harm has been seen. Like with red past 60%. Suddenly we see some relationship between independent testing of blue and red levels, and the energy. Not a perfect relationship, but we don't have illumination levels, the same teams, or the same plants. However it wasn't about quantity of light, but ratios. Where the right ratio's showed my photo-bleaching at 2500ppfd, which is as high as they tried.

There is a huge volume of evidence pointing towards sun-like colour distribution. With anything else we have looked at, having a negative effect.

It's 30 years since I heard the rumour. The Dutch grew better under poly, but didn't know why. Now everyone seems to choose glass so it as perhaps just rumour. However, glass reflects UV quite well. It's used in solar mirrors. Just maybe, with every other colour well presented, the UV treatments work better. Today, it's all about red heavy LEDs and UV testing. For me it was SON lamps and UV. Neither mimics the sun.


Quick pic of some 301s
iu

Just 3 there really.
I once found a vendor of QBs using 4000K+660 but never stock.
 

GoatCheese

Active member
Veteran
A red photon carries 1.8ev (electron volts) and a blue carries 3.1ev
This is why two reds make a blue, and blue takes more energy to make.
Any light with more blue, has a lower ppf/w.
This doesn't help marketing.
For some growers who are into SE Asian and C American sativas or Hazes blue color in the spectrum is a desired factor cause it keeps the plants from stretching so badly and creates more natural spectrum which is less stressful for these sativas.

Many people use a bluer MH bulb along with a redder HPS or just a MH bulb to bloom landrace sativas here on ICMAG. MH bulbs range from around 4500K up to 10 000K in color, iirc, so there’s quite alot of variation in the MH types.

I bought the 3500K Cree cobs rather than the 3000K cause they have more blue in the spectrum, so some people want it there.
 

Cerathule

Well-known member
I can't see the PDF. However if they used the UV to restrict plant growth, then the thc per gram would increase. It's not thc per plant in that case though. It's not indicative of a gain
I'm getting a download error as well, but still the .pdf makes it into the download folder and can be opened.
The study has been carried out to recreate the exaxt ratios of sunlight that this cultivar gets in his adapted habitate, then the UVB increased in several steps, to get this linear increase.
No growth inhibition was observed for both genetics, the dosage was still low and not detrimental to foliage or floral tissue.
 

Cerathule

Well-known member
The plant grew to the lamp, with strange characteristics. Somewhat like reveg, or pure green experiments. Where the plant knows where the radiation is coming from, but has no real idea what to do. Unfortunately the experiment only lasted a few days. The soft tissue around my eyes swelled up from extended exposure, so I couldn't see at all. My flatmate ended the grow, and had to feed me instead.

Might be a lesson in there somewhere.
My own trials with UVC-254nm wreaked great havoc at all plants exposed, even in short time-frames, such as 30s per day.

60904 (1).jpg

I been using a Mercury-low-vapour fluorescent lamp after studies showed these reliably convert foremostly into 254nm photons, though the lowest spike at around ~180nm must be blocked by the glass so that no O3 is generated:
Emission-spectrum-of-the-employed-low-pressure-mercury-vapor-lamp.png

Even a single dosage of UVC made the plants droop, and while the 3s, 8s, 30s plants recovered, the 2min & 8min exposed cultivars showed a lot of damage right after the first night after the start of the experiment.

They also didn't grow as well as the others, the 8min actually not at all except for some internode elongation:
60904.jpg


A week after the experiment terminated the 8min plant died:
60904 (3).jpg


60904 (2).jpg


60904 (4).jpg


There are quite a number of open studies available when using UVC on plants and you are right, they can "see" it, via the UVR8-monomer in the upper regions of UVC, and the cryptochromes.
They do show some specific reactions towards these wavelengths - mostly defensive types, like to build up sunscreen pigments & antioxidants in the exposed tissue.

But most problematic is the genotoxic & mutagenic effect caused by destruction of DNA from UVC absorption:
user434028_pic1366550_1419625807.png

Screenshot_20220323-092853~3.png

As you can see, even UVB has that already. It actually starts briefly before there so UVB can be regarded as the transition into really dangerous frequencies.
With the UVB receptor having its strongest excitation peaking at 285nm - it's like a warning system for extremely dangerous radiation in earth's earlier days, where there was almost no ozone-layer.

But that doesn't mean that other wavelengths can't be destructive, it boils down to strength of influx & also, what molecules the beam actually affects.

Even UVA begins to show a growth inhibition:
user434028_pic1366653_1419643309.png


But also positive effects like an increase response to repair the damaged proteins which transfix chlorophyll-molecules:
user434028_pic1368960_1420061535.png
 

GoatCheese

Active member
Veteran
@snakedope..

What kind of led light did you have again, bro? ... I think you mentioned it already but it’s easier to ask than trying to find the post. Hah-ha

What kind of distance did you keep to canopy with it when you bloomed plants? ..did you run your lights on full power all the time?


There sure was a learning big learning curve when i switch to use my Cree cobs. I’ve noticed i have to be tinkering my lights and exhaust to suit the plants thru out the year/seasons, and the winters up here are a real bitch with leds cause the air is so cold and dry. During the summers i can use maybe 25-30% more power out of my Crees compared to winter and colder times.

If you ran your light full power during a heat wave – perhaps you should have dimmed it down abit or raised up a little or both, but i don’t know the full picture – With leds it’s also about finding the best compromise with power and hanging height for best efficiency, atleast for me.


One thing i have noticed is, that even the air movement from a circulating fan in a tent - if it blows directly at some plants – the dehydration effect is much more dramatic on those plants and the effect on yield and bud size can be quite dramatic as well.

I had one wide Afghan Kush plant in my tent awhile ago- one half of the plant got blown at by the fan and it was missing about half the yield of the other side that wasn’t in the direct line – that plant was too tall and wide all ready and i couldn’t do anything about it – my tent is only 160cm tall.
Potency suffered alot too and how aromatic the weed was and how oily the resin. dramatic difference between the two half of the same plant..

I just changed a 20cm wide circulation fan to a 15cm one with lower rpm setting and it seems to have also improved the dehydration-situation a bit. I have it blowing on the cobs and their heatsinks not on the plants and i feel this way i get the warm air moving in the tent to get the RH% to raise little better.

Air movement seems to be a sensitive thing with leds, how it hits your canopy. At least for me.

My tent is very small 50cm x 90cm x 160cm so little variation in climate or set-up changes usually have fairly dramatic effects ..but it forces you learn how to make it work – and I’m still learning and improving things. Leds are a different animal compared to a hps.



Could the “poor resin heads” led-issue you’re seeing be caused by dehydrated plant tissue = lack of moisture in the resin/plant tissue won’t allow the resin heads to grow properly??

Cause i checked my CBD Cure keeper - that’s on 5th week of bloom – with a 10x loop yesterday and i don’t see an issue with the resin. Most of the resin are globular and i can’t imagine the resin heads on my 250w hps grown plants being any larger.

My point being..
..maybe you could make leds work better for you if you’d try hanging your light abit higher above the canopy and make sure fans aren’t blowing directly at your plants. ..maybe tinker with the exhaust blow out depending on the season/climate -I use a timer on my exhaust –now it’s 15 min ON 1 hour+ OFF during lights on.

:::

For me there’s no going back to the hps. I get same the bud/smoke quality and yields/plant – if not little better with my Cree cobs compared to a Cool Tubed 250w hps . But i only use 85 watts off the wall atm . + i get much better light coverage with three cobs than a single 250w hps, which means bigger yields/tent footprint or grams/watt if you want to use that term.

The costs in energy saving is so huge that there’s no going back to a hps for me. ..if i have to struggle with the cobs during northern winter, then that’s how it is. My plants didn’t like the dry/cold winter during my hps days either so it’s never a perfect situation up here in the winter, unless you have a perfectly controlled room/tent.
 

snakedope

Active member
@snakedope..

What kind of led light did you have again, bro? ... I think you mentioned it already but it’s easier to ask than trying to find the post. Hah-ha
LEDs i have a bunch, but in different watts, all are samsung latest diodes with MW drivers, some are 800w, some 650, some 75\150 (only 2 dim options on those)
What kind of distance did you keep to canopy with it when you bloomed plants? ..did you run your lights on full power all the time?
I tried every option, every height, every dim, i did see a notable difference when i dimmed the panel down and took it more up, i relate that to the light source itself being harmful for humans and plants, my logic and i think pretty much every growers logic is more light more good, at least from my own growing thats what ive seen over the years, LED made me scratch my head... when they are too close plants will die, you call it a side effect of hot spots, could be, but i dont think thats the case.
We need to think about more theories why this happens, my theory is that its just a harmful light, its speculation and i dont really speculate but i dont see other valid reason for this effect.
There sure was a learning big learning curve when i switch to use my Cree cobs. I’ve noticed i have to be tinkering my lights and exhaust to suit the plants thru out the year/seasons, and the winters up here are a real bitch with leds cause the air is so cold and dry. During the summers i can use maybe 25-30% more power out of my Crees compared to winter and colder times.

If you ran your light full power during a heat wave – perhaps you should have dimmed it down abit or raised up a little or both, but i don’t know the full picture – With leds it’s also about finding the best compromise with power and hanging height for best efficiency, atleast for me.
I have a AC inside my 8x4 tent, never got more then 26-27c, as the panels dont give off too much heat, not like HIDs thats for sure, they run cooler but in those watts (the 800w ones) heat is probably 60-70% of HPS from what i saw.
One thing i have noticed is, that even the air movement from a circulating fan in a tent - if it blows directly at some plants – the dehydration effect is much more dramatic on those plants and the effect on yield and bud size can be quite dramatic as well.

I had one wide Afghan Kush plant in my tent awhile ago- one half of the plant got blown at by the fan and it was missing about half the yield of the other side that wasn’t in the direct line – that plant was too tall and wide all ready and i couldn’t do anything about it – my tent is only 160cm tall.
Potency suffered alot too and how aromatic the weed was and how oily the resin. dramatic difference between the two half of the same plant..
You are absolutely right, the effects of direct wind on the plants without stopping is destructive, i saw other growers breaking their head trying to figure out why this happens to them, they tried everything, just didnt move the fans from the plants haha finally they did, and problem solved.

I just changed a 20cm wide circulation fan to a 15cm one with lower rpm setting and it seems to have also improved the dehydration-situation a bit. I have it blowing on the cobs and their heatsinks not on the plants and i feel this way i get the warm air moving in the tent to get the RH% to raise little better.

Air movement seems to be a sensitive thing with leds, how it hits your canopy. At least for me.
I think its sensitive with every grow light, think about it, when u sleep at night with a fan blowing on you, you wake up all dry mouth and woozy, same happens to the plants i think, anyway, i found its not good to blow air on your plants all the time, and if you do, do it with small fans.
My tent is very small 50cm x 90cm x 160cm so little variation in climate or set-up changes usually have fairly dramatic effects ..but it forces you learn how to make it work – and I’m still learning and improving things. Leds are a different animal compared to a hps.



Could the “poor resin heads” led-issue you’re seeing be caused by dehydrated plant tissue = lack of moisture in the resin/plant tissue won’t allow the resin heads to grow properly??
I think this can be a great factor if you have that specific problem, but i didnt had it, also 95% of growers here dont have it, they know what they are doing, they supplied us with killer funk for decades.
Cause i checked my CBD Cure keeper - that’s on 5th week of bloom – with a 10x loop yesterday and i don’t see an issue with the resin. Most of the resin are globular and i can’t imagine the resin heads on my 250w hps grown plants being any larger.
The thing about zoom, is that you cant really know, i judge my plants and other people buds and plants according to what i see, (no talking about pics right now), and i see, feel, smell, nothing, nothing like the good ol days, which was 1 year ago lol
I never said your resin wont be globular under LEDs, but the heads will be smaller, from what ive seen in real world, scores of strains, med and hobby, small heads.
If you cant imagine thats 1 thing, reality will sometimes play with you, we all need to better check everything before we jump the gun.
My point being..
..maybe you could make leds work better for you if you’d try hanging your light abit higher above the canopy and make sure fans aren’t blowing directly at your plants. ..maybe tinker with the exhaust blow out depending on the season/climate -I use a timer on my exhaust –now it’s 15 min ON 1 hour+ OFF during lights on.
I believe what you say will improve overall health and protection measures in LED grows as there are a number of things that make the effect we are looking for, some more and some less, not just 1 measure. also COBs will do better work for LED growers just beacuse they are able to pack more diodes in a smaller chip\space
:::

For me there’s no going back to the hps. I get same the bud/smoke quality and yields/plant – if not little better with my Cree cobs compared to a Cool Tubed 250w hps . But i only use 85 watts off the wall atm . + i get much better light coverage with three cobs than a single 250w hps, which means bigger yields/tent footprint or grams/watt if you want to use that term.
LEDs are the king of spread, im the first to admit it, when you have such low w diodes, you can spread them from here to heaven and remain on the same watt output of a normal HID light but put much more plants under it, as most plants dont need much light to GROW.
Now, the coverage you are talking about is photon coverage, and that you get from your COBs or Panels, but you have completed only 1 side of the matter, the side of ensuring you have enough light total in the space, and this light is good for vegging, as its high photon count overall (by adding the COBs or panels output, like most LEDs mfg do, they add the system output.)
The other side of the coin is what rate (intensity) are you providing that light.
Now i hate repeating it cuz u guys call me a troll, but those diodes lack the rate of any other light source in the market (except very low w cfl, which also make more intensity then the diodes, but are also worthless in terms of flowering because they are under the threshold of luminous flux needed for this type of stress production)
The costs in energy saving is so huge that there’s no going back to a hps for me. ..if i have to struggle with the cobs during northern winter, then that’s how it is. My plants didn’t like the dry/cold winter during my hps days either so it’s never a perfect situation up here in the winter, unless you have a perfectly controlled room/tent.
Look, if something is working for you, and you like it, no one in this world (even not me ;) ) can tell you its not good, just not gonna work.
If u are happy with your results, all i have to say is im very happy for you too.
But science dont lie, science said you need light stress, heat stress, water stress, maybe some bug stress (sounds not valid but ok) and maybe 1-2 things more i dont remember
So, with that being said, with LEDs you provide the light, not the stress ;)
When the diodes reach a point that they will deliver high intensity output (2000+ lm per sec), i do believe we will have the perfect all around growing\flowering machine, but from what i know, they are not gonna make high intensity leds anytime soon.
 
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Ca++

Well-known member
You can get about 1700 from a lm351d in white, or over 2000 in red. Though why you want it from a single LED I'm unsure. I think we have that covered.
 

snakedope

Active member
You can get about 1700 from a lm351d in white, or over 2000 in red. Though why you want it from a single LED I'm unsure. I think we have that covered.
1659921379058.png

You mean this ? i didnt know samsung had such big diodes... never saw them on a panel i think.
Dont most of us get the mid power diodes ?

those output numbers you speak of are at full power i assume, as its 515 at 1050 mA, so maybe 1500 LM at full power ? Very respectable.
Here i am for 15 pages talking about high intensity diodes and you only now remember to show me they have those ? haha :p

Thank you for this, although its still a lil too low, and will need to work at full power at flowering, which makes it not so practical but worth a try, its a good start though for building a DIY for vegging in low amps then flowering in max power... sounds like a plan, and those ones are better then the mid power ones for sure... calculations will have to be different in terms of watt\space as those high power diodes take a lot of electricity compared to the 0.2-0.4w ones.

"I think we have that covered."
Objection ! lol
Why do you think i rant about those mid power low count diodes ?
You have covered the subject of qty of photons\light needed to grow plants in the space by placing many small light emitting sources, like i said, very very good, LED is best at spreading many lights to many places
But whats the cost\catch ? you neglected the intensity, by lowering the intensity of each light source to 80 LM you were able to place much more, but at the cost of dividing the initial intensity source to x diodes you have, see, if you have 600w panel with 1200 diodes, lets say each diode has 80 LM, you have 96000 LM of total light in the space, but you dont have a single source that makes that 96000 LM per sec, you have multiple sources that each makes 80 LM per sec to reach 96K.
INTENSITY IS THE RATE OF LIGHT BEING PRODUCED PER SEC, NOT TOTAL LIGHT IN THE SPACE !
Ask any scientist, Any light expert, ask bumblebee, bugsbee, and the honey bee also

Flowers need light stress (that is if you want the reaction to that stress (glue) to be at its peak. if you want seeds maybe you dont need it too much, if you flower males for pollen maybe also you dont need stress too much (unless your name is hammerhead haha ;) ) more then anything else. heat is also very good inducing stress measures as we all know.
 

led05

Chasing The Present
There are many UVB CFL's around.
the uniqueness of the ones I linked earlier is they are almost exclusively UVB, nothing else, it allows of course for more accurate testing and or to only give nearly pure UVB band and nothing else vs a mix of UV's like nearly every other bulb offers....

LEDs i have a bunch, but in different watts, all are samsung latest diodes with MW drivers, some are 800w, some 650, some 75\150 (only 2 dim options on those)

I tried every option, every height, every dim, i did see a notable difference when i dimmed the panel down and took it more up, i relate that to the light source itself being harmful for humans and plants, my logic and i think pretty much every growers logic is more light more good, at least from my own growing thats what ive seen over the years, LED made me scratch my head... when they are too close plants will die, you call it a side effect of hot spots, could be, but i dont think thats the case.
We need to think about more theories why this happens, my theory is that its just a harmful light, its speculation and i dont really speculate but i dont see other valid reason for this effect.
Now we're sharing, I'll give it a go..... IMO

Your LED's are blasting too narrow a specturm of light and thus your plants are not cycling minerals properly (I'm not going into the 14 or 15 key elements individually but it causes tons of imbalances, I promise you), especially at the lower temps your running for the amount of usable light blasting them from LED in the 400-700nm range.... nearly all LED suck at 745nm +, this matters more than many realize or account for (think how the sun feels on a summer day - seems so simple, that energy matters more than many give credit for, why HPS do so well, it's heavily weighted 600nm + and heavy in IR & Radiant), but you can bleach your plants when youre giving them too much light, it's very obvious, if their not bleaching you can give them more light, LED light too of course - haha.....

I bet you’re watering is tricky, moisture levels off not playing nice like HPS…? Transpiration issues, tacoing leafs, droopy, pointed down ever…?

I have a AC inside my 8x4 tent, never got more then 26-27c, as the panels dont give off too much heat, not like HIDs thats for sure, they run cooler but in those watts (the 800w ones) heat is probably 60-70% of HPS from what i saw.
Brrrrrrr..... I'm freezing in here...... without any radiant / IR that HID / HPS give, let it get warmer bro...... Give more Ca, less Mg too, pretty much everyone can benefit from that....

Range over a week or so of a LED Only room in summer here, common… winter it can be 50F-90F some days, plants don’t seem to mind much - I heat my garage… but point is, under LED especially id let it get warmer buddy

869F1401-2171-4B71-9A75-E81558090EAD.jpeg

You are absolutely right, the effects of direct wind on the plants without stopping is destructive, i saw other growers breaking their head trying to figure out why this happens to them, they tried everything, just didnt move the fans from the plants haha finally they did, and problem solved.


I think its sensitive with every grow light, think about it, when u sleep at night with a fan blowing on you, you wake up all dry mouth and woozy, same happens to the plants i think, anyway, i found its not good to blow air on your plants all the time, and if you do, do it with small fans.
Circulating fans, nothing new there.....


I think this can be a great factor if you have that specific problem, but i didnt had it, also 95% of growers here dont have it, they know what they are doing, they supplied us with killer funk for decades.

The thing about zoom, is that you cant really know, i judge my plants and other people buds and plants according to what i see, (no talking about pics right now), and i see, feel, smell, nothing, nothing like the good ol days, which was 1 year ago lol
I never said your resin wont be globular under LEDs, but the heads will be smaller, from what ive seen in real world, scores of strains, med and hobby, small heads.
If you cant imagine thats 1 thing, reality will sometimes play with you, we all need to better check everything before we jump the gun.

I believe what you say will improve overall health and protection measures in LED grows as there are a number of things that make the effect we are looking for, some more and some less, not just 1 measure. also COBs will do better work for LED growers just beacuse they are able to pack more diodes in a smaller chip\space

LEDs are the king of spread, im the first to admit it, when you have such low w diodes, you can spread them from here to heaven and remain on the same watt output of a normal HID light but put much more plants under it, as most plants dont need much light to GROW.
Now, the coverage you are talking about is photon coverage, and that you get from your COBs or Panels, but you have completed only 1 side of the matter, the side of ensuring you have enough light total in the space, and this light is good for vegging, as its high photon count overall (by adding the COBs or panels output, like most LEDs mfg do, they add the system output.)
The other side of the coin is what rate (intensity) are you providing that light.
Now i hate repeating it cuz u guys call me a troll, but those diodes lack the rate of any other light source in the market (except very low w cfl, which also make more intensity then the diodes, but are also worthless in terms of flowering because they are under the threshold of luminous flux needed for this type of stress production)

Look, if something is working for you, and you like it, no one in this world (even not me ;) ) can tell you its not good, just not gonna work.
If u are happy with your results, all i have to say is im very happy for you too.
But science dont lie, science said you need light stress, heat stress, water stress, maybe some bug stress (sounds not valid but ok) and maybe 1-2 things more i dont remember
So, with that being said, with LEDs you provide the light, not the stress ;)
When the diodes reach a point that they will deliver high intensity output (2000+ lm per sec), i do believe we will have the perfect all around growing\flowering machine, but from what i know, they are not gonna make high intensity leds anytime soon.
plants don't require a specific flow rate of lumens / second to be happy, - it's just like DLI in any species plants, it's accumulation that counts during a day, a week, a month - not a nano second flow rate.... You're failing IMHO with LED's for many reasons, just none of the reasons that you believe it to be, and focusing on one, a flow rate of photons / second (arbitrary thing in your mind) is your hang up.....

This is just some friendly advice

GL and peace
 
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