Will a brighter LED light improve the frostiness of the bud?

[Rocket Soul]

Oh yea was going to say, maybe for live rosin or resin folks would like the enhanced smell but Im after yield. Yield is everything its my currensy, I dont get paid if it dont yield as I just dont smoke anymore. Dabs only for over 2 yrs or so and providing my own flower rosin for just over a year now.

We were talking about my comment that Id read people say sungrown produces more hash. So I wanted to see if I could figure out how to increase yield indoors for hash like flower rosin. I dont remember what was said would have to read it again but it wasnt simple.

I think you said what you thought might do it but would have to involve pheno specific and more than uv. Anyway thats what inspired me. I just was under impression I could find a knock out pheno first and try that at that time.

Right now Im learning as much as I can about keeping mothers and making s1’s and running those. To confirm theyre good and then make a bunch to complete the majority of the project. Make a copy of mother in form of seeds. Might not even need to do that since its inbred so much it might not work out.

I might find a keeper that can be selfed better that hasnt been inbred yet, Im growing other strains too. Im just obsessed with the idea of really having “that” pheno as you really dont have it until then.

I guess its like growing, you grow once youre not a grower. You grow a certain amount of times and solved a few problems, now youre a grower. Same with breeding so not really a breeder. A major rule of breeding is not to create something that exists already.

Tbh just some 400nm already changes the way it smells. Try to add some uv together with whatever reds your light is missing, that way you dont up your blue levels too much which can act against yield.
Where to get it? Try just googling uv led 3535 cree and look for links, even aliexpress could ve an easy source for these. Theyve been fairly efficient for a few years now so your bound to find something but avoid other foot prints like 3528 which tend to be less efficient. Theres also alibaba but usually you have to buy quite a few for it to work out with shipping.

 

[medidedicated]

Tbh just some 400nm already changes the way it smells. Try to add some uv together with whatever reds your light is missing, that way you dont up your blue levels too much which can act against yield.
Where to get it? Try just googling uv led 3535 cree and look for links, even aliexpress could ve an easy source for these. Theyve been fairly efficient for a few years now so your bound to find something but avoid other foot prints like 3528 which tend to be less efficient. Theres also alibaba but usually you have to buy quite a few for it to work out with shipping.

I use mars hydro fce1500 only use one viparspec ks3000 but tend to switch to mars too since theyre discontinued. Im not sure what reds its missing and what to add, do you have any suggestions? Also is this also for increase in cannabinoids? From what I gather folks tend to say more flower rosin yield seems to indicate more cannabinoid production.

Im just not sure how to look at the spectrum and know, like where should it be that the reds are missing?

 

[Rocket Soul]

I use mars hydro fce1500 only use one viparspec ks3000 but tend to switch to mars too since theyre discontinued. Im not sure what reds its missing and what to add, do you have any suggestions? Also is this also for increase in cannabinoids? From what I gather folks tend to say more flower rosin yield seems to indicate more cannabinoid production.

Im just not sure how to look at the spectrum and know, like where should it be that the reds are missing?

My working hypothesis about the red end and the blu/uv end of the spectrum is that you want them to be sloping downwards, a bit like you see in sunlight. And that you want at least as much red <650nm as you have above. The vipar already has this on the red side, the mars not so much: big 660 spike. Try to find 630-640nm diodes with good efficiency: latest gen osram reds are best ive found but they arent very easy to find on the market.
Ive also added 680nm which seems to have worked well, again a bit hard to find nad you would have to add some extra 640 to compensate them. This is just my hypothesis but it seems plausible from what ive seen both in garden results, research litterature and from how the more successful old blurple lights made their spectrums.

 

[Delps8]

I use mars hydro fce1500 only use one viparspec ks3000 but tend to switch to mars too since theyre discontinued. Im not sure what reds its missing and what to add, do you have any suggestions? Also is this also for increase in cannabinoids? From what I gather folks tend to say more flower rosin yield seems to indicate more cannabinoid production.

Im just not sure how to look at the spectrum and know, like where should it be that the reds are missing?

The lights that you're using will generate a good yield of high quality cannabis.

What light levels (dimmer + hang height or PPFD) are you running on your lights now?

 

[medidedicated]

The lights that you're using will generate a good yield of high quality cannabis.

What light levels (dimmer + hang height or PPFD) are you running on your lights now?

Usually 100% about 12-14” away but lately like 16” and 75% since its spring/summer grow. I really dont measure it I just wing it, as bright at close as possible or raised but its hot this season so 75% for less heat and heat/light stress.

I like to hang high 100% and aim for 600-800ppfd across canopy for tops and lowers. Sometimes I hang it closer to push it and step back if I see signs of too much. I just expose everything to decent light and get good results with plant training. I just want to see if playing with lights can raise flower rosin yield aside from genetics as flower rosin is all I do.

 

[medidedicated]

Did some massive defolly more like swazzing. Fuck powdery mildew, whatever avoids it Il gladly swaz. Its growing extra bushy this run. Thick buds all throughout tops tho. Id say light might actually be like 18” high.

 

[Delps8]

Usually 100% about 12-14” away but lately like 16” and 75% since its spring/summer grow. I really dont measure it I just wing it, as bright at close as possible or raised but its hot this season so 75% for less heat and heat/light stress.

I like to hang high 100% and aim for 600-800ppfd across canopy for tops and lowers. Sometimes I hang it closer to push it and step back if I see signs of too much. I just expose everything to decent light and get good results with plant training. I just want to see if playing with lights can raise flower rosin yield aside from genetics as flower rosin is all I do.

Cannabis will thrive at light levels of up to 800-1000µmol, depending on the strain and assuming light is the limiting factor.

If you're not growing at those light levels, I'd switch the conversation away from spectrum because, right now, by turning up the "crop size" dial, you get more weed.

If your plants can't grow at those levels, you might want to check your grow environment because cannabis, as a species, will thrive at those light levels and it will do so as early as week 3-4. Yeh, 1000µmol by week 4. My grows hit that at week 5 but, after having my growing processes reviewed, I'm expecting to get them to 1k a week earlier.

Why so much so soon? Because more light results in a bigger plant which results in a larger crop with higher harvest and bud quality. And you can't add more light later to make up for it.

That doesn't mean that increasing light levels to a plant that's in flower is pointless. The goal is to maximize growth in veg so there's a big foundation that the plant can use to grow lots of flower.

Below is a table I created based on the attached research paper. It shows the percentage of yield increase as light levels were increased.

The difference between 600µmol and 1000µmol is pretty significant, roughly 40%.

Does this hold true for every plant? No, there's no claim of that but what is does show is what cannabis research indicates which is that cannabis thrives at very high light levels (up to 1800µmol in this case) and that yield and crop quality increase as light levels increase.

 

[medidedicated]

Just goes back to what I said first on this thread, genetics and adequette lighting or just fries it. Hash is my goal otherwise I could find a smoker that yields a pound in one plant. Flower yield is the goal too but right now I mothered a plant two yrs ago that yields about half pound one plant and 20% flower rosin yield.

Im new in my studies its not always 20% especially now that I might of lost the pheno its 13% atm. Its like my first car in highschool, learning how to check oil.. Carry a passenger.. Crash it.. Learn from it. I learned that hand trimming can go from 12% to 20% but then lost the pheno?

I only got those yields for a couple runs and it plummitted. I had 20% samples and mini clones before that indicating it was there since the beginning. It was a learning curve but I dry 60/60, no agitation. Very dialed in rosin pressung proceedure maximum consistency.

Only to be worse than ever, if I machine trimmed some of these last clones Id end up with less return I ever got from my pheno, somethings wrong. Hopefully not the dreadful hlvd I doubt it. Just no mother keeping strategies employed. Clones of clones no mother infact. No sterile no back tracking to reselect or monitor all this until too late.

I need to harvest this run its a mother reselection but if im too late its like copying a blurry photo. Its gone. Anyway so my pheno hunt and breed project Im looking for unicorn, 30% flower rosin and high yield, 8oz or more per plant.

Weve talked about this before, my veg plants need unusually dim lighting to grow. Only thing anyone could suggest is raise temps. I did that already just this run I moved to flower room to veg warmer. It didnt want any brighter light but it did grow a little more vigorous but yield to be determined.

With a fresh pheno I got 7-8oz without trying the first few times. As the pheno aged it started to need extra veg time like 10wks vs 7-8wks. Now Im getting clones like last run, 6oz or less with one doing 8.3oz.

I highly suspect manipulating light schedule from veg and flower made it prioritize finishing. Over that pre structure you say before making buds and eventually only buds. More light of course better but its a back and forth thing, I see all is well so I bump it up. If its looking too rough and continueing to be I take some light back.

Its probably 1000ppfd in a lot of places like the center as usual. Maybe more. I cant really do much but control the general canopy and fix the light to that. As you can see parts of it are down lower and some higher. Sometimes its perfect but perpetuating for yrs non stop bound to have a few lesser great looking plants.

I have grows I can bump light up and others where I just cant. Season matters tho. I wont force it on them. My vipar ks3000 only hit 75% never more it just starts to mess with them. Infact this run its on 50%. Ive done it that more more than I have 75%.

Its a good point not to try messing with different lights if I cant get them up to full brightness. Like I said I usually get there with my ts1000 or fce1500 but its just real hot this year. The vipar was always finicky. More veg time just clearly made more yield, now that I recall that 8.3oz clone was 11wks veg as the others were 2 wks behind 9wks veg that round.

The rest is just keeping plant healthy. I considered if something is wrong with my grow but its just been bang on. Some plants dont finish the best but still strong. No one can say anything Im doing wrong for me to improve with all the info I show when all is well. I just ran a new strain and it looked beat to hell where it was too close to light.

Before I forget that reminds me, you really cant get a uniform canopy with the mars hydro. Its like most lights where its below optimal on edges. So its just a balance, provide the best across the canopy and I learned from another user if you raise light like 18-24”.. It becomes uniform like a good 600 edges, 700 around center and 800 dead center.

So thats the balance I look for. Sometimes I lower it a little but forget that. 40% yield increase is just lol, be my guest if you can take over my setup and show me how with my pheno. There are studies and nute manufactures and commercial growers might see an increase doing this or that. Im sure theres more to it.

I get plants that dump yield in a square ft but you increase the space and light etc you dont get the same performance. Same with 2x2 to 2.5x2.5 or 3x3. Im raising yield by genetics first. Its in my 100 seed hunt to find that higher flower yielder on top of dumping hash. Not by forcing light on em when they clearly want less.

Its a process from outside the buildings environment, to inside the building, inside the grow room, inside the grow tent.. To the fabric pots of coco, up the plant to the top. All the conditions within those perameters, RH, temp and water frequency. Will dictate how my plant can perform and how much light it can handle.

Im in dtw coco I dont change the ec once I know what it is. Doing so only created deficiencies which could just be the light and environment, I learned today, causing fading leafs from over transpiring. Ph is always around 5.8-6.2. I need boxfans for circulation to avoid budrot and PM but that impacts environment and needed light intensity.

I could do what everyone else does and clean everything impossibly only to get it again.. Replacing equipment etc. What a nightmare lol Im 19 plants ago I had mold once I harvest these. So Im not changing that, might as well adapt. Theres a lot going on in my setup so I feed 8-12x a day its not a perfect grow dtw coco wise but all else is in check.

The leafs, the runoff EC and PH. All in check. Anyone is welcome to point out where Im wrong Id love to improve.

 

[Farmer's Hat]

My answer the original post. Its always first and foremost genetics. If a plant has excellent genetics and is growing in a nutrient rich medium, it will produce frosty flowers. The plant has to be well fed, obviously. Light helps the plant produce bigger flowers, not more trichomes.
Ive seen plants growing in practically shade, and the trichome production was still better than some of the plants ive grown under optimal conditions. Genetics is really important.
I will scrap plants that are clearly lacking the genetics to produce large amounts of trichomes. Its not worth my time and energy. I make my own seeds for this reason. I can be way more aggressive with the selection process. I will cull up to 50% of the seedlings once I identify that they are lacking vigor. In general, plants that lack vigor produce less trichomes, are susceptible to pests/mold/disease, and are low yielders. Learning to identify vigor in a plant is pretty important, imo.

 

[T macc]

Not sure where this information fits here. Probably useless

I got my fattest buds from flowering under added 810nm, 730nm, 660nm and ~400nm @ 30w each per 4x4 space. Also ran uvb for less than an hour. The 810nm is what increases plant metabolism by warming the leaf temperature, the same way HPS warms leaf temps. HPS bulbs are hot from excess IR

The 810nm diode is what I'd like to see incorporated in future leds. I only used the supplement for 1 grow back in ~2020. The supplemental lights I used were the Exotic boards from Medicgrow. I might hang them back up when I get my Mammoth Novas

 

[Rocket Soul]

Not sure where this information fits here. Probably useless

I got my fattest buds from flowering under added 810nm, 730nm, 660nm and ~400nm @ 30w each per 4x4 space. Also ran uvb for less than an hour. The 810nm is what increases plant metabolism by warming the leaf temperature, the same way HPS warms leaf temps. HPS bulbs are hot from excess IR

The 810nm diode is what I'd like to see incorporated in future leds. I only used the supplement for 1 grow back in ~2020. The supplemental lights I used were the Exotic boards from Medicgrow. I might hang them back up when I get my Mammoth Novas

Id love a little more info on this. Do you have pics? What was your base lighting underneath those supplements? I put some ir boards on an old build for a friend, only to later realize that he didnt have the amps to run all the supplements so never able to see those results.
If it gave you such good results why didnt you use it since 2020??

 

[T macc]

Id love a little more info on this. Do you have pics? What was your base lighting underneath those supplements? I put some ir boards on an old build for a friend, only to later realize that he didnt have the amps to run all the supplements so never able to see those results.
If it gave you such good results why didnt you use it since 2020??

I moved houses around that time. In the process, I stepped on the power cord, ripping the power plug off the board. I ordered replacements that have been sitting in the closet for years. Just got lazy, I guess. Shame.

The comapany is Mass Medical, not Medicgrow lol. Also, the diodes are 840nm, not 810. Was thinking of 910. Looks like they dont sell the "exotic" board anymore with 1:1 840nm:UVA. Closest thing is their supplemental board with 2x 840nm diodes and UVA. Exotic has I think 6 diodes for 840nm. Not sure how it compares

Mass Medical Strains Supplement Bar

.

rapidled.com

2x HLG 320 Quantums. I think Rspec V2. 4x4 tent with room to spare. The strain was Dreamcatcher from Greenpoint. May be strain dependant, but these buds were very dense with the stems being thick all the way thru the bud. Root growth was also rapid throughout flower cycle, forming a mountain to my drippers. I found a few not great pics. 1 is a flower close to the tent wall, the other is a whole plant shot under all red light. I wish I had a plant shot under normal light. I rarely take pictures.

 

[medidedicated]

Busted out the iphone lux meter. Converted on waveform lighting website converter. Red, blue and white led selected before converting. 950ppfd in the center area with some areas hitting 1200ppfd. 500ppfd far edges. I rather have 800-900ppfd across the map.

Notice my “money well wasted” sticker tent the buds aint bigger. The right clone in 2.5x5 growlab tent has the densest nugs. It has higher readings on tops than the left clone but the left clone just aint asking for more. Money well wasted tent has the highest readings but is the smallest buds of them all.

Infact it had a couple leafs fade out and die, could be increases root pressure adding bags around pots. I took those off. Its hot summer. Leafs just dont indicate able to take more so il leave it but the buds aint nearly as pine cone like as the one beside it. Not much more light tho, 75% on the led. fce1500.

Im getting the same density id get at 100%. Frost to be determined but its always frosty. Its the flower rosin yield Im after which you cant judge by looks, the heaviest yielding tend to be less frosty.

 

[medidedicated]

Weird tho as the vipar is meant to be that way but it seems to burn my plants easily when it should only be 800ppfd. Id need to lux meter it but ya, each light model/brand has differences. My plants have always been able to take the mars hydros especially the ts1000’s. Ts1000 is better than these fce’s but I need bar lights.

AND ANALOG DIMMERS. Incase any light manufactures are reading.

 

[Dboybudz]

You know what tho certain light can influence frost I just havent made it that far yet. The DIY light spactrum. It tends to be strain dependent tho and got to learn to read the plants/results. Im hash only so I do want to eventually crack that code.

People keep saying sun grown makes more hash. One said if your plants could talk to you they would ask you for sunlight. Its what they evolved to get light from. Same person said they want to be cultivated they evolved to produce medicine so we value it and grow it so it doesnt. become extinct. Ok hippie talk over.

I was reading everything on bubble hash to be pressed or smoked straight and read sun grown makes trichomes very tough from weather and other factors. When looking with magnifying you would see the stalks breaking off but not the head of trikes. Still obviously do a ton with outdoors and one plant can get a few pounds just thought that was interesting when comes to light.

 

[medidedicated]

The ks3000 is increasibly consistent indeed. The meter barely moves when moving across canopy at close to the same height. Its just something in the light itself that my pheno is rejecting. Idk but I never ran another strain in it yet, weirdly. Done 3 complete grows with it, on my 4th one.

 

[jimihendrix1]

Cannabis will thrive at light levels of up to 800-1000µmol, depending on the strain and assuming light is the limiting factor.

If you're not growing at those light levels, I'd switch the conversation away from spectrum because, right now, by turning up the "crop size" dial, you get more weed.

If your plants can't grow at those levels, you might want to check your grow environment because cannabis, as a species, will thrive at those light levels and it will do so as early as week 3-4. Yeh, 1000µmol by week 4. My grows hit that at week 5 but, after having my growing processes reviewed, I'm expecting to get them to 1k a week earlier.

Why so much so soon? Because more light results in a bigger plant which results in a larger crop with higher harvest and bud quality. And you can't add more light later to make up for it.

That doesn't mean that increasing light levels to a plant that's in flower is pointless. The goal is to maximize growth in veg so there's a big foundation that the plant can use to grow lots of flower.

Below is a table I created based on the attached research paper. It shows the percentage of yield increase as light levels were increased.

The difference between 600µmol and 1000µmol is pretty significant, roughly 40%.

Does this hold true for every plant? No, there's no claim of that but what is does show is what cannabis research indicates which is that cannabis thrives at very high light levels (up to 1800µmol in this case) and that yield and crop quality increase as light levels increase.

View attachment 5476458

While Im not growing in a tent, nor am I using LED. Im in a huge 45 x 45 x 8-10ft ceiling. insulated attic, and have as good of air exchange, as about possible.
Im running a 1000w MMS Halide at 30 inches, and 1050PPFD. At 24 inches its 1650ppfd. And Ive started seeds in this manner as close as 20 inches, with no signs of stress, at all.
In flowering, I can get a 1000w Hortilux HPS as close as 16 inches, and not have a problem. And I can keep temps no higher than 84f. I prefer 80f-84f temps. I also have fans blowing a gentle breeze, from day one. 24/7.
I just wonder why I really never have problems running such high PPFD, and sometimes others are getting stress with much less PPFD.
All I can really pinpoint as a guess, is the fresh air exchange.
Outside, plants get up to 2100umol, and 421ppm Co2, and grow like crazy. I know they dont get a constant 2100umol, but in places like Ecuador-Columbia-Andes Mountains, get extremely high intensity levels, of visible light, and UBA/B-Infrared.

Our UV scale by weather forecasters ect, is basically a 1-11 scale. Though Ive never seen an 11. In South America, along, or close to the equator, they go up to 19!!!!! I read a study they did in the Andes, in Ecuador, at 20,000ft, and they measured UV levels, HIGHER THAN ON MARS!!! Of course nothing grows at 20,000ft, but goes to show one, how intense the UV is at higher altitudes, and/or near the equator.

Jul 9, 2014 · The world record, a UV index of 43.3, occurred in South America at the top of Bolivia's Licancabur volcano in 2003, Yahoo News reports. While a UV index of 12 is considered dangerous, numbers in the 30s or 40s are of course much worse.

The UV duration on a daily average, is brutal, in Quito Ecuador. And this is the Lower UV time of the year!!!
By 8am, its already at 6. 1 hour later, it 10!!!!
By 11am, its at 14!!!!
Then, at 12PM
It stays at 15, for 2 Hours. 12PM-1PM
Then is at 12 at 2PM
8 at 3PM.
Also just using Ecuador as an example, as Columbia, and a few other countries in SA, have brutal UVI, especially in the mountains. Where we know, lots of the best weed in the world, came from this region.

The highest UV index ever recorded in North America appears to be around 11.

Monthly UV Index Trends in Quito​

The UV Index data reveals consistently extreme exposure levels throughout the year, with values typically ranging from 14 to 19. Notably, March shows the highest recorded index at 19, indicating a peak period for sun exposure. High-risk months include February through September, where the UV Index remains particularly elevated at 17 or above. Consequently, both visitors and residents should take precautionary measures, such as wearing protective clothing, applying sunscreen, and limiting sun exposure, especially during midday hours when burn times are reduced to just 10 minutes. Awareness and vigilance are essential to safeguard health against harmful UV radiation year-round.

I just wonder why some get leaf/plant stress with seemingly such low PPFD, while others can get away with running what some would consider extreme overkill.

Compare Quito UV Index with Other Ecuador Cities​

The table above highlights how UV exposure in Quito compares to other major locations across Ecuador. This comparison helps travelers and residents better understand regional sun intensity and plan outdoor activities with sun safety in mind.

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Guayaquil UVI	14	14	15	14	12	11	10	11	13	13	11	12
Machala UVI	14	14	15	14	12	10	10	11	13	13	12	12
Santo Domingo de los Colorados UVI	14	15	16	15	14	12	12	12	13	14	12	11
Cuenca UVI	16	17	18	18	16	13	14	14	17	16	15	15
Quito	17	17	19	19	17	14	15

Quito's solar exposure compared to other cities in Ecuador. Generated using Copernicus Atmosphere Monitoring Service information.​

​

 

[Rocket Soul]

I moved houses around that time. In the process, I stepped on the power cord, ripping the power plug off the board. I ordered replacements that have been sitting in the closet for years. Just got lazy, I guess. Shame.

The comapany is Mass Medical, not Medicgrow lol. Also, the diodes are 840nm, not 810. Was thinking of 910. Looks like they dont sell the "exotic" board anymore with 1:1 840nm:UVA. Closest thing is their supplemental board with 2x 840nm diodes and UVA. Exotic has I think 6 diodes for 840nm. Not sure how it compares

Mass Medical Strains Supplement Bar

.

rapidled.com

2x HLG 320 Quantums. I think Rspec V2. 4x4 tent with room to spare. The strain was Dreamcatcher from Greenpoint. May be strain dependant, but these buds were very dense with the stems being thick all the way thru the bud. Root growth was also rapid throughout flower cycle, forming a mountain to my drippers. I found a few not great pics. 1 is a flower close to the tent wall, the other is a whole plant shot under all red light. I wish I had a plant shot under normal light. I rarely take pictures.

Thanks very much for the info. Ive seen those boards before but never in use.
If i can get a shot at trying this ill try to update you.
Roots: uva and blue is very rootstimulating and my guess is that ir also contributes.

 

[Delps8]

While Im not growing in a tent, nor am I using LED. Im in a huge 45 x 45 x 8-10ft ceiling. insulated attic, and have as good of air exchange, as about possible.
Im running a 1000w MMS Halide at 30 inches, and 1050PPFD. At 24 inches its 1650ppfd. And Ive started seeds in this manner as close as 20 inches, with no signs of stress, at all.
In flowering, I can get a 1000w Hortilux HPS as close as 16 inches, and not have a problem. And I can keep temps no higher than 84f. I prefer 80f-84f temps. I also have fans blowing a gentle breeze, from day one. 24/7.
I just wonder why I really never have problems running such high PPFD, and sometimes others are getting stress with much less PPFD.
All I can really pinpoint as a guess, is the fresh air exchange.
Outside, plants get up to 2100umol, and 421ppm Co2, and grow like crazy. I know they dont get a constant 2100umol, but in places like Ecuador-Columbia-Andes Mountains, get extremely high intensity levels, of visible light, and UBA/B-Infrared.

Our UV scale by weather forecasters ect, is basically a 1-11 scale. Though Ive never seen an 11. In South America, along, or close to the equator, they go up to 19!!!!! I read a study they did in the Andes, in Ecuador, at 20,000ft, and they measured UV levels, HIGHER THAN ON MARS!!! Of course nothing grows at 20,000ft, but goes to show one, how intense the UV is at higher altitudes, and/or near the equator.

Jul 9, 2014 · The world record, a UV index of 43.3, occurred in South America at the top of Bolivia's Licancabur volcano in 2003, Yahoo News reports. While a UV index of 12 is considered dangerous, numbers in the 30s or 40s are of course much worse.

The UV duration on a daily average, is brutal, in Quito Ecuador. And this is the Lower UV time of the year!!!
By 8am, its already at 6. 1 hour later, it 10!!!!
By 11am, its at 14!!!!
Then, at 12PM
It stays at 15, for 2 Hours. 12PM-1PM
Then is at 12 at 2PM
8 at 3PM.
Also just using Ecuador as an example, as Columbia, and a few other countries in SA, have brutal UVI, especially in the mountains. Where we know, lots of the best weed in the world, came from this region.

The highest UV index ever recorded in North America appears to be around 11.

Monthly UV Index Trends in Quito​

The UV Index data reveals consistently extreme exposure levels throughout the year, with values typically ranging from 14 to 19. Notably, March shows the highest recorded index at 19, indicating a peak period for sun exposure. High-risk months include February through September, where the UV Index remains particularly elevated at 17 or above. Consequently, both visitors and residents should take precautionary measures, such as wearing protective clothing, applying sunscreen, and limiting sun exposure, especially during midday hours when burn times are reduced to just 10 minutes. Awareness and vigilance are essential to safeguard health against harmful UV radiation year-round.

I just wonder why some get leaf/plant stress with seemingly such low PPFD, while others can get away with running what some would consider extreme overkill.

Compare Quito UV Index with Other Ecuador Cities​

The table above highlights how UV exposure in Quito compares to other major locations across Ecuador. This comparison helps travelers and residents better understand regional sun intensity and plan outdoor activities with sun safety in mind.​

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Guayaquil UVI	14	14	15	14	12	11	10	11	13	13	11	12
Machala UVI	14	14	15	14	12	10	10	11	13	13	12	12
Santo Domingo de los Colorados UVI	14	15	16	15	14	12	12	12	13	14	12	11
Cuenca UVI	16	17	18	18	16	13	14	14	17	16	15	15
Quito	17	17	19	19	17	14	15

Quito's solar exposure compared to other cities in Ecuador. Generated using Copernicus Atmosphere Monitoring Service information.​

​

That's where I've seen those numbers!

I knew that I'd read a posting by a grower re. very high PPFD's but haven't been able to find it. Until now.

I didn't realize that plants were growing at those altitudes. UV is an issue, no doubt and plants adapt to their environment. The question is if the cannabis plants are different than those grown a lower levels of UV?

Super grow environment— 45 x 45 is huge. No problems getting to the back of the tent to trim the plants!

Re. PPFD - cannabis will grow at 1800 in ambient but it's under pretty unusual conditions. A "gentle breeze" (about 1 meter per second) will ensure that there's a constant supply of CO2 because even cannabis at high PPFD's takes in only tiny amounts of CO2.

What EC are you using in your grows?

 

[jimihendrix1]

That's where I've seen those numbers!

I knew that I'd read a posting by a grower re. very high PPFD's but haven't been able to find it. Until now.

I didn't realize that plants were growing at those altitudes. UV is an issue, no doubt and plants adapt to their environment. The question is if the cannabis plants are different than those grown a lower levels of UV?

Super grow environment— 45 x 45 is huge. No problems getting to the back of the tent to trim the plants!

Re. PPFD - cannabis will grow at 1800 in ambient but it's under pretty unusual conditions. A "gentle breeze" (about 1 meter per second) will ensure that there's a constant supply of CO2 because even cannabis at high PPFD's takes in only tiny amounts of CO2.

What EC are you using in your grows?

I read years ago they experimented by taking a highland Columbian strain, and brought it down to sea level, and you couldnt even tell it was the same plant!!!!!

Also, im only using 5 x 5 out of the 45 x 45.
If memory serves, last grow, at the highest, EC was 2.1-1100-1150ppm in the water. dont know what runoff was, though they were healthy all the way through.

I have 2 box fans on high. On one side of the space I have one Box Fan up in the air, blowing between the canopy, and the bulb. The other is located in a window on the other side of the space. And also an open window 30 feet behind Box Fan #1, and a roof vent, not far off.
Temps vary at the hottest. 88f, if 100f+ outside. Most consistant temps daytime are about 84f. At night they go down to 77f-80f. This is in veg. I flower at night and temps vary 77f-84f. Average is probably closest to 80f.
Ive also had Artificial Intel, figure out how long, and what height to deliver 1.81w sq/m of uva/b, using 2 Solacure 32w Flower Power 4ft bulbs.

The latest study, 2024-published jan 1 2025 on UV/B came from Berlin, and they used several different intensities ect, of UVA/B
They determined that 1.81w sq/m, is the best way to supply uva/b, to marijuana using artificial lighting, and not affect yield, or do great plant damage.
AI determined that 2x 32w Solacure Bulbs, at 24 inches above canopy, need to only be run-17 minutes, MAX- to deliver 1.81w-sq/m, over my 5 x 5 area.

As Ive said before.
Really, the first thing I try and establish, before I even start, is adequate fresh air exchange. I have made this priority one, for 40 years. All bets are off , on the use of high umol, if ya aint got no fresh air exchange. It is my first challenge to a grow room.