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Blue light spectrum in LED's to increase yields

safeman

Well-Known Member
read an scientific article about LED's and their light spectrums a few things I read that surprised me - we all know that the "red" spectrum in led's increase stem elongation - now the blue spectrum - promotes plants compactness and root growth and if use only "blue" spectrum> The research states :lighting plant with blue light alone for the final 72 hours will increase terpene concentrations and also budflower aroma. If one has a dimmimable LED reduce to 50% this elimmtes brightness while increassing the blue spectrum
 

TorturedSoul

Member of the Month: May 2009, Oct 2010, Sept 2017
read an scientific article about LED's and their light spectrums
Got a link?

If one has a dimmimable LED reduce to 50% this elimmtes brightness while increassing the blue spectrum
Wouldn't dimming your LED reduce "brightness" while keeping your spectrum more or less the same?
 

safeman

Well-Known Member
Got a link?



Wouldn't dimming your LED reduce "brightness" while keeping your spectrum more or less the same?
you are right example if it's a 300 watt - dimmed 1/2 would make it 150 watt but for the last 3 days believe it would matter concerning light intensity ? Thoughts? I see what you mean
 

safeman

Well-Known Member
you are right example if it's a 300 watt - dimmed 1/2 would make it 150 watt but for the last 3 days believe it would matter concerning light intensity ? Thoughts? I see what you mean
will get you - need to get the addresses their are two -
 

BAKIND

Well-Known Member
I have always read that the blue light in metal halides was best for stem growth, therefore best for vegetative and that red light in hps for inducing flowering....
 

TorturedSoul

Member of the Month: May 2009, Oct 2010, Sept 2017
I have always read that the blue light in metal halides was best for stem growth
I'd look at it like this:
"the blue light in metal halides was best for compact stem growth"

HPS works fine for vegetative phase. In fact, if you only have one HID for everything, you'll get a better yield from using a high pressure sodium. But you might find that your internodal spacing was greater when using the HPS for vegetative. Which can lead to larger plants that, hopefully, fill in those spaces during the post-stretch portion of the flowering phase.

And that has me thinking... I've looked at a lot of LED grows. They generally do have some frosty buds. But I'm starting to wonder if the spectrum that produces same ends up hurting yield, due to the tightness of the internodal spacing. Yes, being able to control this thing is good - but there's a reasonable limit to good in this particular case, lol. I also don't live in a desert, in terms of humidity, so I know the likelihood of mold and such goes way up when density is too high. I'm not looking for "trying to flower a 100% sativa with a night-light" airiness - but if I cannot ensure some degree of air circulation through the canopy/buds, when the plants transpire moisture (which they do), I've got a big problem.

I'm planning on starting up another grow within the next week or so, and it will use the 160-watt GROWant GR480 LED panel pictured in my avatar. One of the reasons I haven't actually started it yet is because I'm trying to decide about additional light. The panel is, I think, somewhat underpowered for the space I've got, plus my thinking on things such as the internodal length question. I'm wanting to stick the HPS in there, too - but my electrical capacity is rather limited (as is my budget), so I may have to make due with either CFLs, tube-type fluorescent bulbs, or a combination of the two. Decisions, decisions. . . .
 

Mayne

Well-Known Member
i like the stretch myself, when i used the Mars300, i taped off the blue, so it stretched more. Then i found out, cold night temps also drive stretch. Stretch is a problem if you have no head room, and using a weak light because as the cola climbs, the rest of the plant lower suffers because you have to raise the light. Blue light stresses the plant somewhat, because it cant use the blue waves as fast as the Red waves, thus causing frost/ala resin production.
 

TorturedSoul

Member of the Month: May 2009, Oct 2010, Sept 2017
Learning how to manipulate one's plant and its growth, and when and how it is appropriate to do so... that's important.
 

Mayne

Well-Known Member
no doubt about it. each has its own characheristics, and what it likes and doesnt like. Master your bush,lol.
 

ChefDGreen

Grow Journal of the Month: April 2020
This is an old thread, but I would just like to add - I have an LED panel myself that has red and blue switches, I had my plants going with veg switch only for the first three weeks, and just recently decided I should probably be hitting them with all the wattage I can, so I flipped on the red switch. After one day I noticed huge stem growth, not only in length but also in girth. I think both spectrum ranges are important in all stages of plant growth, and making longer internodes is important in veg so that you can 1. Get the biggest plant you can in the veg time you have (if that’s your goal and you’re not doing something like a SOG, and 2) have the bottom of the plant be mostly stem, as that stuff down there gets pruned away usually anyhow. I feel like keeping the Red on until your canopy is about where you want it then going back to blue for the end of veg to stack nodes might be the best way to do it. I’m going to give this a try...
 

Mayne

Well-Known Member
I think it has more to do in the sense of more photons, then the spectrum. When you use both spectrum switches, it doubles the watts at the wall more-less, more watts=more photons=more growth.

Also, the plant digests the Reds easier then the blue, so its "blood" moves faster and easier.

I take it your using a blurple light? Use both switches all the time, up till the last week, then go to just the veg for trich and oil production increase.

So, veg, use both, just raise the light. Flip, Lower the lights, last week, Veg switch. Theoretically, when you flip, you want to double the POWER of the light. Since you cant control the wattage via potencimeter, ( can you ), you just raise the light, and lower in flower.
 

TorturedSoul

Member of the Month: May 2009, Oct 2010, Sept 2017
I think it has more to do in the sense of more photons, then the spectrum. When you use both spectrum switches, it doubles the watts at the wall more-less, more watts=more photons=more growth.
Some combination of both factors, probably.

I take it your using a blurple light? Use both switches all the time, up till the last week, then go to just the veg for trich and oil production increase.
If your plant produces a bunch more trichomes in the last week of its life, won't those "extra" ones tend to be too immature to serve a useful purpose? Other than causing the bud to look shinier in a baggie (which might help someone sell it, I suppose)? I've been wondering about that for a long time.

Regarding more photons versus a better(?) spectrum... It'd come with the cost of another light, of course, but some companies will sell a person one of their products with whatever mix of diodes the customer requests (I'm pretty sure that Mars-Hydro will do this, and even lists both a "full spectrum" and "veg" version of one of their Mars II products). A person could finish with whatever spectrum they wished, while still maintaining the wattage (for lack of a better term).

It's not really relevant to this thread (as it's not LED), but I've read of people finishing their crops with the 7,200K, 10,000K, etc. metal halide bulbs that reefers use. I've never seen a side-by-side (dual garden) comparison using clones from the same mother in which the gardener harvested, dried, weighed, cured, and had samples of each garden tested. An experiment like this would interest me a great deal.
 

safeman

Well-Known Member
This is an old thread, but I would just like to add - I have an LED panel myself that has red and blue switches, I had my plants going with veg switch only for the first three weeks, and just recently decided I should probably be hitting them with all the wattage I can, so I flipped on the red switch. After one day I noticed huge stem growth, not only in length but also in girth. I think both spectrum ranges are important in all stages of plant growth, and making longer internodes is important in veg so that you can 1. Get the biggest plant you can in the veg time you have (if that’s your goal and you’re not doing something like a SOG, and 2) have the bottom of the plant be mostly stem, as that stuff down there gets pruned away usually anyhow. I feel like keeping the Red on until your canopy is about where you want it then going back to blue for the end of veg to stack nodes might be the best way to do it. I’m going to give this a try...

using a full spectrum led (sidel-ighting) in seedling and veg stage here is a tip: use in 1st week of transition/pre-flower stage and use veg nute's 1st week and then second week use 1/2 veg &1/s bloom nute' then once in flower weeks 1-4 full spectrum side-lighting and then weeks 5-8 use just red spectrum then in last 4 days before harvest use blue spectrum only (it has been proven that increases terpenes and essential oils a few LED light companies makes of LED (overhead) that controls specific light needed at each stage (spectrum/intensity)-- Lumigrow and California Light Works 650 watt + sunrise/subset control also you will need $650.00 (+)
 

Mayne

Well-Known Member
Some combination of both factors, probably.



If your plant produces a bunch more trichomes in the last week of its life, won't those "extra" ones tend to be too immature to serve a useful purpose? Other than causing the bud to look shinier in a baggie (which might help someone sell it, I suppose)? I've been wondering about that for a long time.

Regarding more photons versus a better(?) spectrum... It'd come with the cost of another light, of course, but some companies will sell a person one of their products with whatever mix of diodes the customer requests (I'm pretty sure that Mars-Hydro will do this, and even lists both a "full spectrum" and "veg" version of one of their Mars II products). A person could finish with whatever spectrum they wished, while still maintaining the wattage (for lack of a better term).

It's not really relevant to this thread (as it's not LED), but I've read of people finishing their crops with the 7,200K, 10,000K, etc. metal halide bulbs that reefers use. I've never seen a side-by-side (dual garden) comparison using clones from the same mother in which the gardener harvested, dried, weighed, cured, and had samples of each garden tested. An experiment like this would interest me a great deal.
there is actually alot of benefit to clear or young trichs, its good to have all 3 phases.. Each have a different effect, but smooth themselves out with the help of the 3.
 

ChefDGreen

Grow Journal of the Month: April 2020
Good info here, thanks. I'll probably give the last couple days of flower veg mode only.
Yeah definitely worth a try. I’m also going to be doing stem splitting to one if my girls most likely, I wonder how those things will interact.. whether they both help to promote oil production independent of each other, or if it’ll be too much change and stress the plant into stalling.. will be interesting to see
 

Mayne

Well-Known Member
Yeah definitely worth a try. I’m also going to be doing stem splitting to one if my girls most likely, I wonder how those things will interact.. whether they both help to promote oil production independent of each other, or if it’ll be too much change and stress the plant into stalling.. will be interesting to see
lol, funny, Im doing this today actually. But Im going to put a hole in a few branches, and not just the main trunk. I did it last time, and i did notice a bit a more frost. this plant now is realllly frosty already.
 

ChefDGreen

Grow Journal of the Month: April 2020
lol, funny, Im doing this today actually. But Im going to put a hole in a few branches, and not just the main trunk. I did it last time, and i did notice a bit a more frost. this plant now is realllly frosty already.
Did you run mostly blue spectrum during the last few days also? Or are you planning to do that to this gal?
 

safeman

Well-Known Member
I'd look at it like this:
"the blue light in metal halides was best for compact stem growth"

HPS works fine for vegetative phase. In fact, if you only have one HID for everything, you'll get a better yield from using a high pressure sodium. But you might find that your internodal spacing was greater when using the HPS for vegetative. Which can lead to larger plants that, hopefully, fill in those spaces during the post-stretch portion of the flowering phase.

And that has me thinking... I've looked at a lot of LED grows. They generally do have some frosty buds. But I'm starting to wonder if the spectrum that produces same ends up hurting yield, due to the tightness of the internodal spacing. Yes, being able to control this thing is good - but there's a reasonable limit to good in this particular case, lol. I also don't live in a desert, in terms of humidity, so I know the likelihood of mold and such goes way up when density is too high. I'm not looking for "trying to flower a 100% sativa with a night-light" airiness - but if I cannot ensure some degree of air circulation through the canopy/buds, when the plants transpire moisture (which they do), I've got a big problem.

I'm planning on starting up another grow within the next week or so, and it will use the 160-watt GROWant GR480 LED panel pictured in my avatar. One of the reasons I haven't actually started it yet is because I'm trying to decide about additional light. The panel is, I think, somewhat underpowered for the space I've got, plus my thinking on things such as the internodal length question. I'm wanting to stick the HPS in there, too - but my electrical capacity is rather limited (as is my budget), so I may have to make due with either CFLs, tube-type fluorescent bulbs, or a combination of the two. Decisions, decisions. . . .
Yea ! thanks so, so, so much stuff comes around now that it's becoming legal Are you familar with "The Plug Seeds" ? they have some great strains but have/had 5 seeds with no germination 3 of one strain - thinking on making a thread
 
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