Led Flowering Spectrum.

[Barnybud]

Hiya, Id like to hear people's opinions on the ideal light spectrum for flowering. I have done so much reading on this my heads battered with it, alot seem to contradict the previous, so id like to know what wavelengths you consider ideal. Red,far red, blue, infrared, uvb,orange,green. My head is swimming with wavelengths lol. Thanks.

 

[MrBelvedere]

From my understanding the difference will be negligible @MGRox has been doing some testing, plants don't understand these terms we use like wavelength and ultraviolet. They simply want as much intense light as possible during flowering. Intensity being more important than a diverse spectrum. Just my 2 cents.

 

[Barnybud]

I agree but I'm reading that uvb and ir are especially good during late flowering along with green,, even though green can't be absorbed. I'm a little confused.

 

[Toaster79]

You want UV-B and IR from LEDs you're either gonna pay tons of $ or have ridiculously inefficient LEDs heating up your space without any other effect. I'd go with a unit using latest Cree LEDs or COBs or maybe Bridgelux wich are still good but less efficient than Cree. Everything else is a waste of money. There are new units on the market still using cheap chinese shit emitters selling for ridiculous prices. So the best option would be DIYing a unit or get let's say a unit with phillips agro CMH bulb.

 

[Barnybud]

Thanks Il look into them, would adding a reptile heat bulb that gives off infrared supply my girls with IR ?

 

[Toaster79]

You're not looking for heat, you're looking for light emmitance ;)

 

[tags420]

If your adding anything from the reptile world it should be 10mW UVB tubes. Nothing elses.

As for the ideal spectrum...3000-4000k 80cri white leds. Toaster knows what's up cree#1, bridgelux#2

 

[Barnybud]

Thanks,Il look into the uvb tubes. Is their anything you can think of that will add IR also. ?

 

[happy b]

Barnybud if your just starting out your better of sticking with what's been tried and tested . is ther a specific reason your looking into led,like you have a small space which an hps would be too hot for or something?

 

[Barnybud]

Ye very small space, I have to keep it as stealth as possible due to nosey kids and landlord. I have an led but they missed out the IR and I'm pissed about it. Typical Chinese market. So now I'm looking to ad IR and/or UVB. Thanks.

 

[MrBelvedere]

You don't need IR or uvb led at all. You're good to go now with the Chinese ufo led and no reason to be pissed at all :)

If you're having plant problems please describe what is happening? Good luck

 

[Barnybud]

Its a 200W panel light 5W leds, its awesome during veg and early flowering but from the reading I have done IR or UVB are needed during the final flowering phase. I'll be flushing soon so guess I will find out, but it just doesn't smell like it did with a 250hps.

 

[happy b]

I don't mean to be a buzz kill but you really should have joined up BEFORE buying a light . there's loads of members with experience in growing in a small area who could have pointed you in the right direction for a light.
what's the specs of your grow room?

 

[Wee Zard]

Its a 200W panel light 5W leds, its awesome during veg and early flowering but from the reading I have done IR or UVB are needed during the final flowering phase. I'll be flushing soon so guess I will find out, but it just doesn't smell like it did with a 250hps.

I'm guessing that he temperature is a bit lower than it was with the hps as well?
You may have to warm them to get the same terpene profile.

Disregard the "information" about IR, and UV. They are NOT needed to flower.
I say this from experimentation, and experience.
I've grown some superior bud with nothing but 660 nm. red and ~460 nm. blue.

The only other wavelength That you might want to look into is far red, ~720 nm.
But that needs to be on a different time schedule from the LEDs.
If you apply far red for a half hour after light's out you can speed up flowering a little.
But that's not a job for LED's quite yet.
Incandescent sources are much less expensive.

UV-a is of no use and UV b and c are NOT necessary to synthesize THC.
They can, in fact. damage your plants and fry capitate glands.
Without the attrition of UV-c, un-pollinated cannabis can continue to pile on capitate glands of high quality resin.
For this reason, I filter out the UV for my outdoor/greenhouse plants.
It can get pretty thick. :)

The added advantage of a 2 color light is some control of the morphology.
If you use a dimmer on one or both colors to change the R:B ratio.
Crank up the blue for tighter internodes and to limit height.

And general info.
Plants can, and do use green light.
Just not as efficiently as they use red, and blue.
I find that adjusting my lights for minimum reflection from the leaf gives me the most bang for my watt.
I "tune" the ratio until the plant almost looks black for maximum absorption.

Built my own lights and have been using LEDs for years.
The only reason I stopped using LEDs for flowering is, sunlight costs naught. :)

(Actually, I'm frugal, but the birds could not pronounce that.) :D

Aloha,
Wee 'zard

 

[Barnybud]

Thanks for reply on this everyone, like I said ive read uni studies that seems to contradict each other, anyway Wee zard cool pics, love the tric pic, ye temps are lower than hps need to beef it up. My led wavelengths : 660nm:630nm:430nm:460nm. 3.3.1.3 regarding 720 do incandescent bulbs supply it ? What about CFLs, ? The light has 2 switches for blue and red and isn't dimmiable ive had both red and blue on during flower and veg because I have mates that keep mh on during flowering and they do really well. Its doesn't look a crap led even though I wasn't a lot of cash, but something don't seem right. Thanks for your post . Cheers.

 

[Wee Zard]

regarding 720 do incandescent bulbs supply it ? What about CFLs, ?

CFLs have almost no 720 nm. but do leak a little UV.

Incandescents? FR in abundance.
Along with a lot of IR.
But the best source is those "blacklight" bulbs for illuminating posters,etc.

As you can see from the chart, the UV-a output is dwarfed by the FR/IR output.
The FR is sufficient to hasten bud swell.

That's why it seemed that something was missing.
LEDs run cooler. So HPS growers start to panic at the 7th week when nothing seems to be happening.
It's just the nature of the beast. Wait another week or two and the buds fatten up just like sunlight/HPS buds do.

If that week or two is a problem, use the F.R. to speed it up a tad.
With our Island power costs the extra current consumed by the F.R. was about the same cost as another week or two of full lighting, so I opted to be patient.
Then, got my medical license and started flowering in sunlight so it's no longer an issue.
Have managed to get some decent "penetration" with the LED array.
This was grown under 56Watts with 90 degree lensing.

Just put her under the 150W. to flower here.

The 150W is an un-lensed, 180 degree, lambertian spread, heavy on the red.

Google "the pragmatic use of LEDs" for some reliable information on led growing.
And I have extensive picture albums on other sites.
Try Googling "Weezard LED" and see what pops up. :)

Aloha,
Weeze

 

[Toaster79]

Just wandering which LEDs produce 180* beam angle?

 

[Wee Zard]

That's the default with unlensed LEDs

 

[Toaster79]

What unlensed LEDs? Unlensed as in without the lens dome or without secondary optics?

 

[Wee Zard]

Without secondary optics.

Most LEDS radiate in a lambertian pattern right out of the box.
The inverse square law will limit the height of your plants without secondary lensing.
60° lensing is a wee bit tight, but 90° is just about right. :)

Aloha,
Weeze