LED Lab 2009

[igrowwitmatches]

cant hurt to get better results. lower watts of led usually compare to higher watts of other kinds of lighting so 25 watts of led (may) get your some good tight nugs... were as 25 watts of cfl gonna give you popcorn.. and not alot of it ... i'd look at some of kanna's diy led setup threads and rig em like he says do what he says with the leds he says and you should be happy with your results

edit: search gardenscure.com for the thread

 

[knna]

Hi Knna,
How are your try outs coming? Do you have any advice on "hybrid" lights? (CFL and LEDs)

If you are looking for an efficient setup with easy heat management, at the current state of art of LED and its price/perfomance, go hybrid is the way to go.

CFLs provides light on the full PAR range, that possible eliminates problems due to the lack of a certain wavelenght, and do it for cheap. Then adding RED leds, that are the cheaper ones and runs on the lower forward voltage, thus they are by far the cheapest LED alternative, enhances the spectrum efficacy and increase the average energy efficiency of the setup.

IMO, its the easiest, simpler and cheaper solution currently on small grow cabs.

Type S CFLs are too low power ones to use them for growing, IMHO. On the same shape, you have the type L, that offers more power, radiant intensity and way higher energy efficiency. 36W ones are 17" long, so there is little space where you cant use them

Of course, using white LEDs, or white and blue LEDs instead of the CFLs, would result on higher energy efficiency, so you can use less watts. If stealthness is esential, and/or heat dissipation difficult, I would use LEDs instead of CFLs. Otherwise, CFLs are still cheaper on the long run.

White LedEngin's LED havent good specs at all. There are currently cheaper and more reputated white LEDs on sale for cheaper. While they offer some options than arnt avalaible at other brands, as high power deep red and far red, on conventional colors I dont think LEDEngin's LEDs are a good choice.

Be carefull to not confuse "nominal watts", the name of the product, "3Watts", "5 Watts", etc, with the actual power being burned.

On the LED industry, ratings for 1Watt LEDs refers to those running at 350mA, 3W for those running at 700mA, 5W for 1A. It results on red LED of those categories running at 0,8W ("1W"), 1,8W ("3W") and 3W ("5W").

InGab LEDs (blue, white) burns power more close to the nominal rating, but still below it. For example, those "5W" white LEDEngings burns 3.6W on average.

You can get the actual power consuption of a given LED multiplying its Vf (forward voltage) by its If (forward current.

For a 0.7sq ft setup (what height?), you need very little power. True 25W is a very good figure for that space.

 

[DaVinci]

Hi everyone, I'm new to the thread, but just read the whole thing in one sitting. Damn this is good stuff. This thread kicks ass. I had a few questions to start off and make sure I'm on the same page with everybody here....

Knna,

Has anyone done a grow test comparing white LED's (no reds or blues) with CFL's of comprable spectral output? If so I'd be interested to see the results. I have done a little searching but haven't found anything yet. I'll keep searching.....


Weeze,

Nice new lamp! Have you had the 660nm LED turned back up yet? and did stretching resume? also, how're the results from the "blacklight?" it seemed from previous posts like you are still testing it, yes?


Also, I'm a little confused on pulsing. I think I understand the theory behind it as posted, but has anyone on the forum tested pulsing LED's with a batch of ladies yet?

 

[billyjojimbob11]

Once again, I will have to agree with Knna, the ledengins imo are less efficient even for 660nm leds. I tried 660nm and ended up with looser than average led buds, but I am not ruling out that others have had sucess. The photos below are from all cree leds.
Xrc Red and blue
Xre White (Q3)

The next post will be a similar clone using warm whites instead of neutral white. I can tell you with much confidence that the warm whites outperform the neutral already, 2 weeks to go.
After that I will post red+blue+yellow/orange 590nm from Edison Opto.

This is from neutral white, clone 12/12 after rooting.

 

[knna]

billyjojimbob, thanks for sharing your results. Can you detail the composition of the arrays used with the WW and with the NeutralW?

Has anyone done a grow test comparing white LED's (no reds or blues) with CFL's of comprable spectral output? If so I'd be interested to see the results. I have done a little searching but haven't found anything yet. I'll keep searching.....

On one of the tests grows, one array of 12 LEDs, 6 Royal Blue and 6 Whites (Cree XRE group 15 and Q4 (color WF) respectively) failed. While it gets repaired, he put a 65w CFL. Growth remained the same, maybe a little slower with the CFL. LED array was below 25W. Red array continued working all the way, both with white/blue LEDs and with the CFL.

 

[billyjojimbob11]

billyjojimbob, thanks for sharing your results. Can you detail the composition of the arrays used with the WW and with the NeutralW?

26 clones
At the moment, I am using procyon + 12watt (14w total @360ma) spot light.The procyon is as you know, 100w, now I am using...12 watts of P4 warm white, before I was using 12 watts of Q3 neutral white.

My first setup was procyon + 40watt 3600k cfl, the cree spot light works much better because with the 60deg lenses I can focus the light directly on the plant with more intensity than the cfl, and I place it @ 45deg angle @ 20cm to allow all leaves top and bottom to get light, promoting a much denser plant with good bottom growth. I put into flower after 2 weeks of rooting under blue/red 1:1 with their mothers. What happens is the stretching period begins when the plant is 5-10cm tall, after the stretching period ends, the plant is usually under 40cm to make one huge cola with small stem and only 4 to 6 sets of fan leaves.
Bear in mind, there are 26 clones of these under 112 watts of led, so that rounds out to 4.5 watts per plant, and the last plant had 8gr. The next ones 10+gr im hoping It is a perpetual microsog, so I am able to watch the group improve as the lights are changed. The plants mostly exposed to warm whites will be due in 2-3 weeks, but the buds are already much larger than the neutral whites. It may be the extra IR in the warm whites, or just more plain red that is making the difference. The spot light is positioned most intensly on the 2-4 week old clones, but all of the plants get white light.

 

[LeoRexTyrannus]

Oh I'm not dead far from it, just haven't checked in, in awhile, I've got the thread subscribed so they still mail me weekly the conversation. I just have to say Weezard I have a few of your gallery pics saved, and those leafs on your plants are huge, I want leafs like that.

My THC Bomb mother is about 2' ft right now under 2700K 68W CFL. I'm going to be purchasing a 5000K CFL for more vegging power (I know I know wrong spectrum, its all they had locally so sue me)

I found a chart somewhere I lost which showed that 5000K has massive amounts of blue over 6500K, if someone can debunk or substantiate that please do by messaging.

I can't wait until this harvest is finally over aiming for July/August, and then I will construct my panel.

Thank you all for your continued research and if anyone has suggestions about a quality CFL for vegging (I've been looking at Envirolite and Hydrofarm as well as the Energy Miser bulbs at 1000bulbs) please do advise me.

 

[Weezard]

He lives!

He lives!

Oh I'm not dead far from it, just haven't checked in, in awhile, I've got the thread subscribed so they still mail me weekly the conversation. I just have to say Weezard I have a few of your gallery pics saved, and those leafs on your plants are huge, I want leafs like that.
...
.

We just worried a little when your post ended mid-post.

Mahalo, she's got fans the size of my hand.
That's just a W.W. clone in DWC w/deep-red & a knockoff UFO
Love that DWC!

That girl got too big too fast and I hadda bloom her.
That's also the one that stopped da stretch when I turned down the red in the bloomery and resumed when I turned it back up.


Glad ya didn't faw down go boom.

Weeze

 

[devilgoob]

whats up weezard? I dont feel like writing sentences, so Ill list food for thought for you.

using anywhere from a 15 to a 35 degree lens or focus light on the top of the main central cola which might be great for light signaling. maybe an led focused at higher intensity is better than an hps in terms of radiated heat and subsequent drying up and burning when intensity is too high (bulb is too close to tops).

I thought since chlorophyll a also has a spike around 420-430nm maybe that blue instead of the 380nm would be better.

Maybe some of this has been talked about, but oh well!

good job weezard.

LEDS RULE

 

[LeoRexTyrannus]

I didn't know the post was cut off and I'm far too lazy to go back and figure out why you guys thought I bought the big one.

My THC Bomb mother is one sexy bitch, crystals in all the right places, tall strong, double the size of her now gifted siblings. I'd take a picture if you guys want to see out of curiosity. The girl is very healthy but she didn't veg as much as I'd like since I'm using the before mentioned 2700K.

I'm leaning towards getting something in the range of 100W+ CFL of 6500K. My girl is doing so well she just needs more blue to really accelerate her vegetation so I can clone this sexy bitch.

Now I'd lean towards LED for this since I know for a fact there is no doubt LED excels at vegetation utterly humiliating even the mighty CMH in this regard.

I simply can't justify the price for a UFO original knockoff or otherwise knowing I could construct something that would do a much better job for far less. If anyone can give me hard numbers on how many emitters I'd need of the LEDEngin in Blue at 15W to optimally cover my 4x4 ft area then please do as the CFL's I'm looking at are in the range of 50-70 + S & H

Just seeing your results makes me fiend to go LED, Weezard if that was what a knock off did to your leafs I'd love to see what one of your IGD's does (Improvised Growing Device).

I definitely want to see more photos of actual growth from you fellows especially the ones having good success you're inspirations to hundreds if not thousands of people that have been burned by inferior products blaspheming the name of LED

@Billyjoe warm white in CFL parlance has massively more red than neutral white, neutral having more blue, if this is equivalent in LED terms then that would explain the difference.

 

[billyjojimbob11]

@Billyjoe warm white in CFL parlance has massively more red than neutral white, neutral having more blue, if this is equivalent in LED terms then that would explain the difference.

Yes, however, it is a known fact that red phospors in red leds are not as efficient in lumens than its greener counterpart. That said, as we all know, lumens are not the name of the game. I have plenty of 635 red in my array already, however it seems that the warm whites have a fair amount of far red, and that along with some orange, yellow, orange red, and some green is what Im after, and it seems to make at least some difference. I will post some dried photos of the buds in a couple of days, they are truley some of the tightest and dankest buds i have ever seen. Using a big cfl or couple of small ones helps the plants without question. My opinion is that Cree white leds as well as a couple of other companies, offer white and warm white leds in which I can direct more light where I need it, rather than having a cfl just shooting of light in all directions. I bought cree warm white bin P4 that shoots off 85 lumens per watt in any direction I need, and outperforming CFL warms by 25 lumens per watt at a superior color. Sorry but CFL's have been trumped by Cree.

 

[DaVinci]

good posts, billyjoejimbob. I shall give thee mad props-eth. I may try to replicate your CFL/White LED comparison later this summer.

I figure if we get SEVERAL people with similar hard results PROVING that white LEDs can outperform CFL's, the naysayer's will have no choice but to pay attention. And that's exciting.

I'm holding out for the XP-G line that's supposed to come out at the end of the summer. It's a new record for lumens per watt, but we'll have to see if radiant output matches my hopes. I don't think they have released spectral data on it yet.

Is anyone else a little irritated that Cree measures only luminous intensity of their white LEDs, and not radiant like they do with the blues? I mean I know they're marketing toward people, not plants, but come on Cree. It'd be nice to know.

Goddamn we need a good spectrometer for this thread. If we could do home comparisons of our lamps, that would make these experiments so much cooler.

 

[LeoRexTyrannus]

I'm not saying CFL's are better than LEDs just in my grow right now they make sense whereas I don't have the funds to do LED right and honestly I don't think there's enough solid research for medical patients to really depend on an all LED solution at the moment, Weezard's setup seems to work fine for him but we need something where we know X=X and we can garuntee it, for some folks this is crucial.

Now LEDs will best CFL when we figure the ratios out for optimum or as close to as possible. CFLs have a major feature in that they're full spectrum and therefore are 100% PAR efficient. CFL's use UV light to excite the phosphors into emitting light.

My question is from my understanding I know that ozone generators are using extremely high powered UV LEDs, why is it not possible to couple this with phosphors for 100% PAR using Rare Earth phosphors to even further enhance spectrum.

I don't know if anyone has addressed this, I do know the UV emitters in ozone generators are so powerful to look at them for a moment is said to blind you near instantly. Is it not possible to build a CFL powered by one of these?

 

[Oldmac]

CFLs have a major feature in that they're full spectrum and therefore are 100% PAR efficient. CFL's use UV light to excite the phosphors into emitting light.


I don't know if anyone has addressed this, I do know the UV emitters in ozone generators are so powerful to look at them for a moment is said to blind you near instantly. Is it not possible to build a CFL powered by one of these?

Hey there Leo,

I have to address the first misconception you have here, PAR by it's very definition is light that is usefull to the plant for photosynthesis. Since the plant does not need everything in the light spectrum for growth, full spectrum bulbs cannot be 100% PAR effiecent. (This is why most LED experimenters are using specific wavelenght LEDs and why they can be more efficent then a light that wastes wattage on spectrums the plant can't use).

Second, most ozone generators use small fluorecent tubes that produce UVB. (I have not seen any using LEDs, yet).
UVB is extremely dangerous, never look at a UVB light source directly, it WILL BLIND you, not because it's so powerfull but because it will fry your retinas. UVB is extremely harmfull to humans, it is why people use sunscreen outdoors and wear shades...so they don't burn thier skin or damage their eyes.

Like my father said to me many, many years ago..."son, you gotta learn to walk before you can run."

 

[Weezard]

Aloha LRT

You said; "My question is from my understanding I know that ozone generators are using extremely high powered UV LEDs, why is it not possible to couple this with phosphors for 100% PAR using Rare Earth phosphors to even further enhance spectrum."

Good idea!

There was an attempt in the late '60s to do just that, called "Gro-lux" tubes.
Fluorescent tubes with predominantly red and blue phosphors.
Gave off a pink/lavender light.
I used them for a while.
They were not dramatically "better" but that's not surprizing.
All grows are limited by their weakest link.

With light, nutes and water.

"Enough is sufficient, more than enough is too much." -Weeze

 

[knna]

I have to address the first misconception you have here, PAR by it's very definition is light that is usefull to the plant for photosynthesis. Since the plant does not need everything in the light spectrum for growth, full spectrum bulbs cannot be 100% PAR effiecent. (This is why most LED experimenters are using specific wavelenght LEDs and why they can be more efficent then a light that wastes wattage on spectrums the plant can't use).

I cant agree with that statement, Oldmac.

No any light is 100% PAR efficient.

First off, some of the light is reflected back, for any wavelenght. And how much is reflected of each wavelenght depends of the plant specie.

So what is 100% efficient would depend of how we define it:

-in terms of emitted or absorbed light?

Inada did it in term of irradiance (light reaching plants) and get the maximun photosynthesis (that we may call 100% efficient, although is far from it) at 670nm.

While McCree did it for absorbed photons (thus, eliminating differential absortion between wavelenghts) and get the max for a range between 600 and 625nm.

-in terms of energy or in terms of photons?

In terms of energy, the longer the wavelenght, the better. While in terms of photons, all the range between 600 and 680nm have a very similar photosynthetic effect.

For those reasons, botanist long ago agreeded to use PAR photons as the best possible figure that correlates with induced photosynthesis.

It may be corrected for the exact spectrum, but then you need to clearly state how are you doing it, as result will depend of the way of conversion.

Aditionally, there is no 2 plants species that uses exactly equal same spectrum.

The highest problem with the PPFD (Photosynthetic Photon Flux Density=irradiance in photons for area unit, generally sq meter, uE/m2) is that it overstate the photosynthetic effect of blue, and in less degree, green photons. The higher the content of light in this region, the higher the error on the correlation photosynthesis-uE/m2.

But for most light spectrums, this induced error is relatively low. And PPFD (uE/m2) is still the widely avaliable figure that correlates with induced photosynthesis the best.

This pic explains that induced error, but shows too how photosynthesis response is relatively flat and dont have anything in common with chlorophills absortion in lab:

This is the McCree curve, that represents the amount of photosynthesis (CO2 absorbed) for mol of photons absorbed of each isolated wavevand (2nm).

Notice that photosynthesis induced by blue isnt higher than that induced by green. And that chlorophills absorbance is very different. But its a very well proven fact (by some thousand of scientific studies) that photosynthetic response of live plants not correlates with chlorophills absorbance.

Not only because there is other secondary pigments, as carotenoids, but optimal absortion of each wavelenght of light by a chlorophill molecule depends of its spatial position (depth and orientation) into the leaf and of the protein to it is binded. So a identical molecule of Chl a may absorb the best 700nm photons (as the central one of the Photosystem I), 680nm photons (as the Reaction center of the Photosystem II) or 610nm photons (as happens on many chloroplast of plants growing under HPSs).

Resuming, total amount of photons, irrespective of each wavelenght is a very good indicative of total photosynthesis induced. It may be corrected by the exact spectrum for more accuracy yet, but these corrections are little, and may be done carefully. PUR and PYF figures are the most used corrected figures.

There was an attempt in the late '60s to do just that, called "Gro-lux" tubes.
Fluorescent tubes with predominantly red and blue phosphors.

Glad you talk about it, Weezard. Along the years many growers have checked themselves that Grolux tubes (and others very similar from other brands) didnt work better than standard ones for growing plants. Any spectrum efficacy enhancement was negated by their lower energy efficiency, that resulted on a lower uE emission, but with better efficacy (PYF/PPF).

Growers knows this since 20 years ago, but still we have marketing hype about spectrum alone, without any reference to photon's emission. Sad. Surely we deserve it.

 

[knna]

26 clones
At the moment, I am using procyon + 12watt (14w total @360ma) spot light.The procyon is as you know, 100w, now I am using...12 watts of P4 warm white, before I was using 12 watts of Q3 neutral white.

Thank you very much, billyjojimbob11.

Its very enlightening. These are the typical spectrums fo Cree whites:

The highest difference is between the Coolwhite and the others. But Neutral and Warms really arnt so much different.

Neutral has a little more green and less red, so maybe it may explain it. But amount of yellow is pretty similar, aswell as far red. But probably the main difference between Neutral and Warm is that the lattest have way less blue.

So I think that your result may be related to the Procyon already delivering more than enough blue, so the aditional blue from the neutral are having very little effect.

 

[dontae1000]

erb is cheap to veg expensive to flower, led will never produce dense nugs , now if your going up to 100w and adding several yeah then why not, but whats the point? the hobbiest mentality at some point has to be kept in check, grow rooms full of cluter and light panels and the need to make constant adjustments to the most basic things like the light(its height from the plants) u provide gets old and u have to ask yourself for what?

 

[knna]

erb is cheap to veg expensive to flower, led will never produce dense nugs , now if your going up to 100w and adding several yeah then why not, but whats the point? the hobbiest mentality at some point has to be kept in check, grow rooms full of cluter and light panels and the need to make constant adjustments to the most basic things like the light(its height from the plants) u provide gets old and u have to ask yourself for what?

No need to do constant adjustement for growing with LEDs.

You might not confuse our experimental setups, where we try to minimize LEDs count due they are expensive yet, with the oncoming way of use of LEDs.

On the future surely most growers will have an static setup, with LEDs lighting on as plants grows. Probably will be systems that regulates both what LEDs are on, attending to plant's height and distance, and its running current in order to achieve the required light densities at each stage automatically.

But in this initial stage of development, we trade off initial investment for a little more work.

 

[Oldmac]

Hello knna,

Please check what I wrote about "100% PAR efficent" lights again.

I was pointing out to Leo his misconception that a "full spectrum light was 100% PAR effiecent".

That is what we strive for in creating a LED based grow light, but like you point out is impossible to achieve. And it holds whether we look at converstion of electron energy to photons or photon energy recieved by the plant.

I think we are in agreement here. You where just more technical about it.

And always good to see your posts, which brings me to a question:
What do you think of running the Cree's whites instead of fluorecent tubes?
Which of Cree's whites would you use with a combo of Cree's Reds (635nm) and LedEngines far reds (660nm)?