Led Users Unite!

YungMune said:

okay heres what i know about leds....the regular blue led is actually 9k color temp...the red is 1800. so you really cant veg with nothing but 9k leds and flower with nothing but 1800...you cant mix red and blule that gives you a ultra violet color (alot of manufacturers do this, they know nothing about growing weed) and we all know how rediculous it is to grow with a "black light" .also leds are extremeley 1 spectrum unlike a cfl it gives a vast specturm becuase it uses energy and gas to make light just like the sun,....leds only use energy.....so whats the solution
INCLUDE GREEN LEDS TO GIVE U THE CORRECT SPECTRUM. if u mixed 3 blue leds and 1 green led you would get about a 6500k color which is correct for vegging.....if you mix about 8 reds to 1 green color you get around 2k-4k color temp for flowering...i havent tried to grow with it yet but i will in a month after i can get some clones...i already have the leds and already tested the colors...im pretty sure it will work.

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Unfortunately, your theory is incorrect. Light doesn't combine to give you different wavelengths. Combining the red and blue doesn't give you UV. If you were to put a spectrometer under the UFO lights we've been discussing, the only UV that you would see present in the spectrum would be if the manufacturer included a UV wavelength among the LEDs in the lamp. If you were to put anything black-light reactive under a combination of only the red and blue LEDs, it would not fluoresce. UV is a specific wavelength, and the combination of other wavelengths does not produce a new wavelength of light.

As far as using green LEDs, there is no benefit whatsoever to using them, as the plant simply doesn't "see" this wavelength of light. In fact, the only recommended use is to use green LEDs for going into your grow room during the dark cycle and being able to work (since the plants are not affected by green). I would advise you not to waste your money on combining green LEDs with anything. If you want to use green LEDs for something, convert a Mag-Lite flashlight to use green LEDs so you can see your crop during its dark cycle./

CaptainPointless said:

Unfortunately, your theory is incorrect. Light doesn't combine to give you different wavelengths. Combining the red and blue doesn't give you UV. If you were to put a spectrometer under the UFO lights we've been discussing, the only UV that you would see present in the spectrum would be if the manufacturer included a UV wavelength among the LEDs in the lamp. If you were to put anything black-light reactive under a combination of only the red and blue LEDs, it would not fluoresce. UV is a specific wavelength, and the combination of other wavelengths does not produce a new wavelength of light.

As far as using green LEDs, there is no benefit whatsoever to using them, as the plant simply doesn't "see" this wavelength of light. In fact, the only recommended use is to use green LEDs for going into your grow room during the dark cycle and being able to work (since the plants are not affected by green). I would advise you not to waste your money on combining green LEDs with anything. If you want to use green LEDs for something, convert a Mag-Lite flashlight to use green LEDs so you can see your crop during its dark cycle./

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so do you have a spectrometer and have tested ufos?

YungMune said:

so do you have a spectrometer and have tested ufos?

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No. I do not have a spectrometer and have not personally tested UFOs. But science does not lie. If there is no UV spectrum present, no effects due to UV will be present. In essence, what I'm saying (again) is that combining different colors of light does not change the spectra that are present. Now, this is not saying that other colors cannot be produced due to combination. White light, which itself is not a color, is a combination of all colors (most efficiently created using RGB), whereas black is the absence of all color (or rather, the absorption of all visible wavelengths of light, created most efficiently using CMY).

455nm LEDs put out a MINUSCULE amount of UV light, just as 660nm LEDs put out a MINUSCULE amount of IR. So again, IF any effects were noted (ie, fluorescence), it would be due to the tiny amount of UV light present in the blue LED's spectrum, NOT due to the combination of multiple light sources. The only reason you see purplish light (note: NOT UV) when these colors are combined are because the eye is interpreting them and presenting them to the brain in such a way that it can comprehend. If our brains could comprehend it, we would see each color individually, even when combined. This is simply not possible, though, as our brains have not evolved this far yet.

Plants have no brain, no eyes, and have evolved to sense different portions of the electromagnetic spectrum than the human eye. This is why certain components of a plant (chlorophyll A+B, carotenoids, phycoerythrin, etc...) have peaks on their respective response curves -- because they only respond at certain wavelengths. Green light does not happen to fall on any of the peaks of any major response curves, thus, the reason that plants appear green (because the plant reflects this light).

I don't really know where I was going with that, but my main point still remains that green light is useless in the growth aspect of plants, and that red and blue LEDs do NOT combine to form UV. As for using a spectrometer, when and if I have the money to do that, I will gladly purchase one to use in the testing of various grow lights.

By the way, can I ask where you got your numbers for the color temperatures of the various color LEDs?

When I calculate using Wien's Displacement Law, I get 9000K color temp = 321nm in the EM spectrum (UV-B). A typical 450nm LED has an equivalent color temp of 6439K.

1800K = 1609nm in the EM spectrum (IR-B). A typical 660nm LED has an equivalent color temp of 4390K, and a typical 630nm has an equivalent color temp of 4599K.

Take into account that, again, color temperature only relates to the human interpretation of light, and thus is limited to the visible (and near visible) spectrum. I can't say it enough...plants simply ARE NOT humans. They don't sense light, gravity, moisture, heat, or anything else the same way that we do. It seems it is difficult for some people to understand the distinction between our species.

EDIT: Color temperature is based on a spectral width, rather than a specific wavelength, so saying 450nm = 6500K isn't completely accurate, but it's a ballpark type figure to show relationship.

I've seen some sweet buds on youtube with LEDs, so someone is doing something right. The people that say they suck must have had bad luck or just didn't know what they were doing. Those other expesive lights ( MH & HPS ) put out a lot of light but they also put out a lot of heat ( wasted energy ). If you puy that heat energy into light ( LED ) it only seems that you'd be much better off with your grow and the power company. I'm interested in an LED grow of my own soon, looking on ebay for some deals.

I think a lot of the backlash against LEDs was from when they were so expensive. Just 1-2 years ago, a supposedly good 90w UFO was $400-600. Now you can get a supposedly better one for $125 - $150. (I keep saying "suposedly" because until I finish my first grow with them I retain a healthy dose of skepticism).

I think the claims that these lights are as good as 600-1000w HIDs are probably ridiculous, but I have seen some tests/reports that seem credible that they can provide similar results to 300-400w HIDs. If this proves true, when you factor in the reduced need for ducting and heat management, and their reduced operation costs and greater longevity, the possibilities become quite attractive.

One potential downside to LEDs you don't hear a lot about is that even if they do provide similar results to HID lights with 2-4 times the wattage, their coverage area is significantly smaller - which is compounded by the fact that LEDs are usually hung much lower than HIDs. This is ok for growers like me who only want small grows, but could be more problematic for people wanting large grows.

Personally, I feel my expectations are fairly reasonable: If my new 90w UFO can do the job of one 250w HPS with almost zero heat for only $150 - I'll be very happy. Even if it can only equal a 150w HPS, I'll be reasonably satisfied. If it performs worse than a 150, I will be disappointed. Only time will tell, but I felt it was worth a try and decided to buy one and see what happens...

I just put some seeds under one of these bad boys...

http://stealthled.com/





updates/results to follow

CypressRyan said:

I just put some seeds under one of these bad boys...

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I read the stats on that. I'm no expert, but it sounds awesome. GL - I look forward to hearing about your results!

Shiitake said:

I read the stats on that. I'm no expert, but it sounds awesome. GL - I look forward to hearing about your results!

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The stats look good in my opinion too! But, for same cost you could get two or three top of the line 90w UFOs. Also, I read somewhere that 1W LEDs were more efficient than 3W and 5W LEDs. Any one know if that's true?

ThaiBoy said:

The stats look good in my opinion too! But, for same cost you could get two or three top of the line 90w UFOs. Also, I read somewhere that 1W LEDs were more efficient than 3W and 5W LEDs. Any one know if that's true?

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Yea my LED is only 90w, but my grow is only about 2 square feet (4-5 cubic feet). My measly 150w HPS was more than adequate for my space, so I'm just hoping my UFO will do just as well or better and do it a few degrees cooler.

I'm using a Glowpanel. I think it's 14W. Red & Blue lights. works pretty well so far.

snoopyman2 said:

I'm using a Glowpanel. I think it's 14W. Red & Blue lights. works pretty well so far.

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What are you growing with it (plant# and size), and are you using any supplemental lighting or just the one panel?

Shiitake said:

What are you growing with it (plant# and size), and are you using any supplemental lighting or just the one panel?

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I started with Glow Panel 14w. It's a good light from real company. I use it for side lighting now. Along with my Lighthouse 2009 an 2010 models, I have 194w total LED. I'm running pure LED now. One thing I've noticed is VERY short inter-nodal length. Anyone else out there using LED find that they have shorter inter-nodal lengths after you switched?

Not with the HGL units. Stretching occurred in tests. With the prosource 180 jumbo, stretching was not there. Short tight nodes, nice bushy ladies. Not stretched. Stacked, but stretched were the 126 ladies.

Lumigrow are tall but FAT...a nice balance compared between the two companies with the 126 or the 180.

Fun stuff!

As I have stated in another post, I used 2 glowpanel 45's and I love em. I am planning on buying another 45 as well as 4 14w panels to mount horazonally on my walls. My last grow I put 1 of the 45s on its side during flowering producing very good results. My yield was 1.5 oz dry per plant.

Steveat1 said:

there is a guy online who's site is called growitled.com i am curious if anyone has used the products he sells. i have spoken with him, and he has been pretty forthright. even suggesting supplemental lighting, but I am mainly curious about results. He is no rocket scientist, but seems pretty honest. feedback feedback feed me please!!!!

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The chritmas light LEDs are just outdated technology. Everyo one of these lights is coming out of the same factiry in China.They grow and they will produce especially if you supliment them with someything else, but they are not the bang for the buck. The newest LED grow light is made in Texas and their grow lights are on www.g2led.com I use these guys and Justin is your source. I would give them a call. 970-506-0525. It was out of the hightimes 35th ana toward the back of the mag where I found this info.

Bob

here is a few pics of some Alaskan Ice I got going. this is 1 week of veg.

I put my hand in the pic to show some sort of scale

bobkessel said:

The chritmas light LEDs are just outdated technology. Everyo one of these lights is coming out of the same factiry in China.They grow and they will produce especially if you supliment them with someything else, but they are not the bang for the buck. The newest LED grow light is made in Texas and their grow lights are on www.g2led.com I use these guys and Justin is your source. I would give them a call. 970-506-0525. It was out of the hightimes 35th ana toward the back of the mag where I found this info.

Bob

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I don't know...their information seems pretty sound, but I just don't think I could justify spending $1,000 on an 85W lamp. Now, if they had a verified grow with them, I would be far more inclined to look more seriously at them. But you're talking about bang for the buck...these lights come out at over $11.00/W, which is higher than any other light on the market. Might be more efficient, but I would definitely need to see a grow from start to finish with these before I would jump in on that bandwagon.

axjnkee, your plants look pretty healthy. Would you mind taking some pics of them in normal daylight or at least incandescent lighting, so that we can all see the depth of green, and how the plants look normally?

sure, I can do that. it wont be until the next watering though.

bobkessel said:

The chritmas light LEDs are just outdated technology. Everyo one of these lights is coming out of the same factiry in China.They grow and they will produce especially if you supliment them with someything else, but they are not the bang for the buck. The newest LED grow light is made in Texas and their grow lights are on www.g2led.com I use these guys and Justin is your source. I would give them a call. 970-506-0525. It was out of the hightimes 35th ana toward the back of the mag where I found this info.

Bob

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I dont use any supplimental light, and my last grow did just fine.