Led Users Unite!

CaptainPointless said:

In all honesty, their information is extremely suspect. I would avoid this seller and wait until you find a well-made product at a good price. The eBay one you found is certainly not worth $230 (price+shipping).

Taken from the listing - "In our 2009 LED Growlight Showdown, our winner (Lighthouse Hydro) employed a unique LED. After our analysis, we concluded that the reason for the win was the use of a mixture of 625nm UV/Blue LED's rather than the traditional blue 660nm LED's used in all other LED systems tested. This is confirmed from the spectrum usage graphs above."

First, the fact alone that they are using UV LEDs means nothing. The cost of ONE UV-B LED (the UV spectrum that matters, from 280nm to 310nm), is around $800. So you can be assured that the UV LEDs they use do nothing for your grow. Second, if you read what I just quoted, they reference "the traditional blue 660nm LED's" -- See the problem here? 660nm is red, as are the 625nm "UV/Blue" LEDs they also reference. The whole listing talks about the importance of the spectrum, yet they can't get a simple thing like this correct?

Using IR LEDs helps nothing unless they are used correctly, which is not the case when they are on during the entire light cycle. "Tri-Band & Quad Band using Orange & Standard White LED's are worthless – educate yourself" -- Completely false statement. THEY are the ones not doing their research. White LEDs are used to supplement the overall spectrum, and orange (612nm) LEDs are used to aid in carotenoid production.

They even contradict themselves in their own listing -- "On Usable Lumens output alone, a 90w LED does not match the 400 HID light system. In usable lumens alone the conversion is more like 90w LED = 310w HID (HPS/MH)." and later,

Lastly, they just have a ton of typos -- not the signature of a reputable seller or product. Sounds pretty fishy to me. If I were you, I wouldn't buy that one. There are so many fakes out there. The people selling those know that the majority of the buyers have no method of measuring (ie: spectrophotometer) the actual wavelength of the products they sell. Thus, many of them are simply lying about the spectra that are included. Don't get "shiny-toy-syndrome." Just because something says it's a great new 2010 model "proven" or "guaranteed" to perform, doesn't mean it actually does.

To everyone who is looking to eBay to buy LED grow lights, make 100% SURE you read through the ENTIRE listing. There are a lot of scam artists out there, but if you're careful, you can "" them out. Read everything. Look for typos. Compare information. Above all, use common sense. If something looks too good to be true, it typically is.

Click to expand...

One pic was about two weeks ago and the other today started flowering a week in a half ago.

streeaaaacchhhhh!!

Dr.RR said:

LED Users: Hopefully I can find some info in here! I'm planning on purchasing a 90w UFO for my veg phase only; plants will then be transferred under a 400W HPS. Thing is, I don't know which model and brand to purchase. I've had my eye on this model, does anybody know if it's worth it & if this "2010" model should really outperform others?

http://cgi.ebay.com/NEW-2010-model-90w-HO-Cree-Lighthouse-Hydro-6-Band-USA_W0QQitemZ270507614875QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item3efb82a29b

Click to expand...

I bought and use the 2009 Lighthouse Hydro 90w light. I've ordered the 2010 light and await it's arrival.

I have corresponded with the Gotham Hydroponics which distributes the lights and they have provided me a great deal of information on their lights (which I've posted on another thread). In my opinion, their lights perform great thus far, but I have not yet gone to the budding stage yet.

I went with Lighthouse/Gotham because I thought their lights fit my price/performance needs. There are cheaper and more expensive LED grow lights out there. I went with a midpoint in price and hopefully a highpoint in performance! Time will tell.

Gotham is currently testing the Lighthouse 2010 (multi-band) model against the 2009 (dual band) model light on growing tomatoes. The test grow just started but I think in 90 days they will have a drop of evidence w.r.t relative performance of the two lights.

Hope this helps...

CaptainPointless said:

In all honesty, their information is extremely suspect. I would avoid this seller and wait until you find a well-made product at a good price. The eBay one you found is certainly not worth $230 (price+shipping).

Taken from the listing - "In our 2009 LED Growlight Showdown, our winner (Lighthouse Hydro) employed a unique LED. After our analysis, we concluded that the reason for the win was the use of a mixture of 625nm UV/Blue LED's rather than the traditional blue 660nm LED's used in all other LED systems tested. This is confirmed from the spectrum usage graphs above."

First, the fact alone that they are using UV LEDs means nothing. The cost of ONE UV-B LED (the UV spectrum that matters, from 280nm to 310nm), is around $800. So you can be assured that the UV LEDs they use do nothing for your grow. Second, if you read what I just quoted, they reference "the traditional blue 660nm LED's" -- See the problem here? 660nm is red, as are the 625nm "UV/Blue" LEDs they also reference. The whole listing talks about the importance of the spectrum, yet they can't get a simple thing like this correct?

Using IR LEDs helps nothing unless they are used correctly, which is not the case when they are on during the entire light cycle. "Tri-Band & Quad Band using Orange & Standard White LED's are worthless – educate yourself" -- Completely false statement. THEY are the ones not doing their research. White LEDs are used to supplement the overall spectrum, and orange (612nm) LEDs are used to aid in carotenoid production.

They even contradict themselves in their own listing -- "On Usable Lumens output alone, a 90w LED does not match the 400 HID light system. In usable lumens alone the conversion is more like 90w LED = 310w HID (HPS/MH)." and later,

Lastly, they just have a ton of typos -- not the signature of a reputable seller or product. Sounds pretty fishy to me. If I were you, I wouldn't buy that one. There are so many fakes out there. The people selling those know that the majority of the buyers have no method of measuring (ie: spectrophotometer) the actual wavelength of the products they sell. Thus, many of them are simply lying about the spectra that are included. Don't get "shiny-toy-syndrome." Just because something says it's a great new 2010 model "proven" or "guaranteed" to perform, doesn't mean it actually does.

To everyone who is looking to eBay to buy LED grow lights, make 100% SURE you read through the ENTIRE listing. There are a lot of scam artists out there, but if you're careful, you can "" them out. Read everything. Look for typos. Compare information. Above all, use common sense. If something looks too good to be true, it typically is.

Click to expand...

I too was put off by the obvious inaccuracies in what was posted. Bear in mind they were quoting an article they did not write from GrowBoys Magazine (http://growboys.nl/). Perhaps the inaccuracies were in original article, or maybe introduced when they quoted it. Heck the whole thing magazine article could have been faked, but I'm guessing there really was a contest and the Lighthouse light won.

I agree that "Tri-Band & Quad Band using Orange & Standard White LED's are worthless – educate yourself" is a blatantly stupid statement and reflects badly on their credibility! At this point, nobody really knows what spectrum is best for growing your target species and growth phase. Older tech Chinese LED lights are a lot cheaper, and if cost is the primary concern, may be the way to go.

I ended up buying their light anyway because it had the 660 reds and because of the grow contest they supposedly won. I really wish I could get my hands on the GrowBoys Magazine article to judge for myself the legitimacy of the results.

By the way, their 2010 model does have HO (high output) white LEDs. Gotham said they were used because they could produce blue light more efficiently then blue LEDs as well as fill out the spectrum making it closer to a natural sunlight spectrum.

Personally, I think it's an assumption that producing a natural sunlight spectrum is ideal for growing what you want to grow. Sure there's the evolution argument, but I suspect an "unnatural" spectrum will produce better results from a yield/watt perspective. Now it's up to use LED growers to discover the ideal spectrums for each growth phase. Get to it and try to use scientific methods!

ThaiBoy said:

I too was put off by the obvious inaccuracies in what was posted. Bear in mind they were quoting an article they did not write from GrowBoys Magazine (http://growboys.nl/). Perhaps the inaccuracies were in original article, or maybe introduced when they quoted it. Heck the whole thing magazine article could have been faked, but I'm guessing there really was a contest and the Lighthouse light won.

I agree that "Tri-Band & Quad Band using Orange & Standard White LED's are worthless – educate yourself" is a blatantly stupid statement and reflects badly on their credibility! At this point, nobody really knows what spectrum is best for growing your target species and growth phase. Older tech Chinese LED lights are a lot cheaper, and if cost is the primary concern, may be the way to go.

I ended up buying their light anyway because it had the 660 reds and because of the grow contest they supposedly won. I really wish I could get my hands on the GrowBoys Magazine article to judge for myself the legitimacy of the results.

By the way, their 2010 model does have HO (high output) white LEDs. Gotham said they were used because they could produce blue light more efficiently then blue LEDs as well as fill out the spectrum making it closer to a natural sunlight spectrum.

Personally, I think it's an assumption that producing a natural sunlight spectrum is ideal for growing what you want to grow. Sure there's the evolution argument, but I suspect an "unnatural" spectrum will produce better results from a yield/watt perspective. Now it's up to use LED growers to discover the ideal spectrums for each growth phase. Get to it and try to use scientific methods!

Click to expand...

I can agree with you to a point about the eBay listing. I would also like to read the original article to see what's up. But looking at that listing, I simply could never bring myself to purchase something that had as many errors in the sales pitch as that did.

However, I still hold my ground about saying some of the things I said. The way I look at it, if there is any energy wasted in any way, that's energy that could have been diverted to stimulating growth. For example: If there are 90 1W LEDs in this, and if even one of those LEDs is an IR or UV-A LED, then that is one less 660, 630, 612, or 455nm LED that is used. Since neither IR or UV-A has any major purpose in photosynthesis, that is just a wasted space on the circuit board.

For those who are curious, IR is used to interrupt the dark cycle, and effectively shorten it to allow more time spent in the light cycle (ie: 14/10, rather than 12/12). In the case of the UFO light, since the implication is that the IR LEDs are on at the same time as all the other LEDs, this purpose is effectively circumvented, rendering the potential benefits null and void.

UV-B light is used during the flowering phase to induce THC and resin production. As I said before, UV-B LEDs simply are not feasible, as they are exorbitantly expensive. If one wants to add the UV-B spectrum, the most affordable and effective way is using reptile bulbs, or tanning bulbs.

CaptainPointless said:

I can agree with you to a point about the eBay listing. I would also like to read the original article to see what's up. But looking at that listing, I simply could never bring myself to purchase something that had as many errors in the sales pitch as that did.

However, I still hold my ground about saying some of the things I said. The way I look at it, if there is any energy wasted in any way, that's energy that could have been diverted to stimulating growth. For example: If there are 90 1W LEDs in this, and if even one of those LEDs is an IR or UV-A LED, then that is one less 660, 630, 612, or 455nm LED that is used. Since neither IR or UV-A has any major purpose in photosynthesis, that is just a wasted space on the circuit board.

For those who are curious, IR is used to interrupt the dark cycle, and effectively shorten it to allow more time spent in the light cycle (ie: 14/10, rather than 12/12). In the case of the UFO light, since the implication is that the IR LEDs are on at the same time as all the other LEDs, this purpose is effectively circumvented, rendering the potential benefits null and void.

UV-B light is used during the flowering phase to induce THC and resin production. As I said before, UV-B LEDs simply are not feasible, as they are exorbitantly expensive. If one wants to add the UV-B spectrum, the most affordable and effective way is using reptile bulbs, or tanning bulbs.

Click to expand...

As far as the Lighthouse 90w 2009 model goes, it only has two wavelengths: "red" 660nm and "blue" 425nm in an 8:1 ratio. I'm not sure if either wave length can be called UV or IR. Some people think 660nm is the best single red color to use, but the LEDs are more expensive than the 630nm ones. As far as the 425nm LEDs go, I haven't seen much posted about them, but according to the GrowBoys article, was the key difference. I'm not sure how they could know that, but like I said, I never could get my hands on the original article. Maybe the difference was just more overall intensity. The specs on the 2009 model say it puts out 3900 lumen which seems relatively good compared to other 90w LED grow lights -- though few companies even report lumen output!

When I get the 2010 model, I'll post the specs!

Finally, for what it's worth, here's the detailed information I got from Gotham Hydro about the 2010 light:

"Now to answer your question. It matches the action spectrum almost
PERFECTLY. At least it matches the blue and red peaks in the same ratio
(about 50%/50%. Hence the ratio of HO white vs red. The whites actually put
out more blue than blue LED's do, hence the switch to white HO LED's. There
is an excess of light in the blue to orange wavelengths. The main purpose
of the HO whites are for the Blue (100% efficient) it contributes also to
the mid-range 500nm-600nm (20% efficiency) as well as the red (76%
Efficiency).

Breakdown is as follows (Usable Lumens per LED): Efficiency had been
calculated for.

White Cree HO Warm: Blue 22 Lumens, Middle 20 lumens, Red 8 Lumens
White Cree HO Cool: Blue 33 Lumens, Middle 13 lumens, Red 5 Lumens
Cree 660nm: Blue 0 Lumens, Middle 0 Lumens, Red 18 Lumens
Cree 630nm: Blue 0 Lumens, Middle 0 Lumens, Red 30 Lumens

From there is it math. Compared with a standard Gro Pro UFO Blue/Red Model

Bridgelux Blue 460nm: Blue 10 Lumens, Middle 0 Lumens, Red 0 Lumens
Bridgelux Red 660nm: Blue 0 Lumens, Middle 0 Lumens, Red 8 Lumens

Now compared with the Lighthouse UV

Cree 660nm: Blue 0 Lumens, Middle 0 Lumens, Red 18 Lumens
Cree 425nm: Blue 15 Lumens, Middle 0 Lumens, Red 0 Lumens

So there is the numbers.
Keep in mind that the coverage on this new one. Id not quite as good as the
UV model. You want to cover no more than 4sqft with this white HO in SOG or
ScrOG growing method.

So.. these new HO are awesome for Veg and Cloning as they have way more
Blue than anything else. UV is nice for Late Veg / Early Flower and then
the last 2 weeks I would hit the plants with the HO again. I am curious to
see if the intensity of the HO will do more for yield than the Red of the
UV."

ThaiBoy said:

As far as the Lighthouse 90w 2009 model goes, it only has two wavelengths: "red" 660nm and "blue" 425nm in an 8:1 ratio. I'm not sure if either wave length can be called UV or IR. Some people think 660nm is the best single red color to use, but the LEDs are more expensive than the 630nm ones. As far as the 425nm LEDs go, I haven't seen much posted about them, but according to the GrowBoys article, was the key difference. I'm not sure how they could know that, but like I said, I never could get my hands on the original article. Maybe the difference was just more overall intensity. The specs on the 2009 model say it puts out 3900 lumen which seems relatively good compared to other 90w LED grow lights -- though few companies even report lumen output!

When I get the 2010 model, I'll post the specs!

Finally, for what it's worth, here's the detailed information I got from Gotham Hydro about the 2010 light:

"Now to answer your question. It matches the action spectrum almost
PERFECTLY. At least it matches the blue and red peaks in the same ratio
(about 50%/50%. Hence the ratio of HO white vs red. The whites actually put
out more blue than blue LED's do, hence the switch to white HO LED's. There
is an excess of light in the blue to orange wavelengths. The main purpose
of the HO whites are for the Blue (100% efficient) it contributes also to
the mid-range 500nm-600nm (20% efficiency) as well as the red (76%
Efficiency).

Breakdown is as follows (Usable Lumens per LED): Efficiency had been
calculated for.

White Cree HO Warm: Blue 22 Lumens, Middle 20 lumens, Red 8 Lumens
White Cree HO Cool: Blue 33 Lumens, Middle 13 lumens, Red 5 Lumens
Cree 660nm: Blue 0 Lumens, Middle 0 Lumens, Red 18 Lumens
Cree 630nm: Blue 0 Lumens, Middle 0 Lumens, Red 30 Lumens

From there is it math. Compared with a standard Gro Pro UFO Blue/Red Model

Bridgelux Blue 460nm: Blue 10 Lumens, Middle 0 Lumens, Red 0 Lumens
Bridgelux Red 660nm: Blue 0 Lumens, Middle 0 Lumens, Red 8 Lumens

Now compared with the Lighthouse UV

Cree 660nm: Blue 0 Lumens, Middle 0 Lumens, Red 18 Lumens
Cree 425nm: Blue 15 Lumens, Middle 0 Lumens, Red 0 Lumens

So there is the numbers.
Keep in mind that the coverage on this new one. Id not quite as good as the
UV model. You want to cover no more than 4sqft with this white HO in SOG or
ScrOG growing method.

So.. these new HO are awesome for Veg and Cloning as they have way more
Blue than anything else. UV is nice for Late Veg / Early Flower and then
the last 2 weeks I would hit the plants with the HO again. I am curious to
see if the intensity of the HO will do more for yield than the Red of the
UV."

Click to expand...

I will say, the people at Gotham Hydro seem to have more of a grip on things than the eBay distributor. Their comparison on usable lumens between the lights is pretty accurate, but still flawed. It's just flawed in a way that allows people to still gain an understanding for what they're dealing with when they buy the product.

I'm saying it now, and I'm sure I'll say it again. Plants don't measure light in lumens, no matter how much we wish upon a star for them to. Lumens are a strictly human measurement, related to the spectrum of light that our eyes have evolved to be most sensitive to (555nm), which consequently is the spectrum that plants are LEAST sensitive to. So the manufacturer saying that their UFO light puts out 16,400 lumens is a rather skewed statement. Sure, it may put out this many lumens, but not all of those are useful. In fact, I can guarantee the majority of those lumens are produced from the white LEDs they have included.

Does anyone see anything peculiar here? Generally speaking, people buy lights (any type) based on the color and the lumen rating. It follows that a manufacturer would try to increase these numbers as much as possible to sell more lights. White HO LEDs = higher lumen rating per LED = higher overall lumen rating per lamp = higher sales = higher stacks of money for the manufacturer.

The Cree HO White LEDs are unnecessary in the quantities that have been included. NOTE: I did not say that they are not necessary at all, just how many they have. This is why Gotham told you that they would be great for vegging. This is correct, as the Cool White LEDs put out a decent amount of the blue light necessary for vegetative growth. However, neither the Warm or Cool Whites put out enough red light to aid much in flowering. Their efforts could have been better spent in using higher wattage 660nm LEDs to compensate for the lack of this spectrum. But then again, that would drop the lumen rating and people wouldn't get "shiny-toy-syndrome."

eBay user looking for grow lights, stumbles upon that listing -- "HOLY CRAPOLI!!! 16,400 lumens from only 90W?! I MUST have this Holy Grail of lighting technology. And for only $200?! I think I just creamed myself. I'd be in heaven if only it were from the U.S...HOLY SHIT IT IS!" -- passes out and wakes up with mouse hovering over the "BUY IT NOW" option.

eBay user looking for grow lights, sees a rather boring looking 90W UFO -- "Psh, just another one of those Chinese knockoffs again...and I'd have to order from China...I don't like those people, they have little feet. Only 2000 lumens? I could piss more than that in my sleep. No wonder it only costs $140...tell me more...what is this 660 crap? 666 is only 6 away...must be the devil."

lol, thought we could all use a laugh.

CaptainPointless said:

I will say, the people at Gotham Hydro seem to have more of a grip on things than the eBay distributor. Their comparison on usable lumens between the lights is pretty accurate, but still flawed. It's just flawed in a way that allows people to still gain an understanding for what they're dealing with when they buy the product.

I'm saying it now, and I'm sure I'll say it again. Plants don't measure light in lumens, no matter how much we wish upon a star for them to. Lumens are a strictly human measurement, related to the spectrum of light that our eyes have evolved to be most sensitive to (555nm), which consequently is the spectrum that plants are LEAST sensitive to. So the manufacturer saying that their UFO light puts out 16,400 lumens is a rather skewed statement. Sure, it may put out this many lumens, but not all of those are useful. In fact, I can guarantee the majority of those lumens are produced from the white LEDs they have included.

Does anyone see anything peculiar here? Generally speaking, people buy lights (any type) based on the color and the lumen rating. It follows that a manufacturer would try to increase these numbers as much as possible to sell more lights. White HO LEDs = higher lumen rating per LED = higher overall lumen rating per lamp = higher sales = higher stacks of money for the manufacturer.

The Cree HO White LEDs are unnecessary in the quantities that have been included. NOTE: I did not say that they are not necessary at all, just how many they have. This is why Gotham told you that they would be great for vegging. This is correct, as the Cool White LEDs put out a decent amount of the blue light necessary for vegetative growth. However, neither the Warm or Cool Whites put out enough red light to aid much in flowering. Their efforts could have been better spent in using higher wattage 660nm LEDs to compensate for the lack of this spectrum. But then again, that would drop the lumen rating and people wouldn't get "shiny-toy-syndrome."

eBay user looking for grow lights, stumbles upon that listing -- "HOLY CRAPOLI!!! 16,400 lumens from only 90W?! I MUST have this Holy Grail of lighting technology. And for only $200?! I think I just creamed myself. I'd be in heaven if only it were from the U.S...HOLY SHIT IT IS!" -- passes out and wakes up with mouse hovering over the "BUY IT NOW" option.

eBay user looking for grow lights, sees a rather boring looking 90W UFO -- "Psh, just another one of those Chinese knockoffs again...and I'd have to order from China...I don't like those people, they have little feet. Only 2000 lumens? I could piss more than that in my sleep. No wonder it only costs $140...tell me more...what is this 660 crap? 666 is only 6 away...must be the devil."

lol, thought we could all use a laugh.

Click to expand...

I agree with everything you have said.

Lumens, can be useful comparing lights with "exactly" the same spectrum, but since you can't get measured spectrums from LED grow light manufacturers, this don't work in practice.

In defense of Gotham Hydro, they do not know if the 2010 model, even though it has more lumens, is any better or worse than the dual band 2009 model and are doing there own grow tests now. They too are searching for that perfect spectrum!

This is a fantastic discussion. I'm sure many people who are on the fence will benefit by reading through this whole thread. There are many, many manufacturers out there, some reputable, some not...we're just trying to help you all weed through the bullshit that the disreputable ones feed you. A good manufacturer knows they don't need to hype everything up...if the product is worthy, it will sell itself.

I guess what I'm trying to say is, no matter what manufacturer you go for, or where you choose to buy your lights, just watch out for hype. The more seemingly overwhelming information a product has (ie: stating on the first picture you see of a 90W light that it puts out 16,400 lumens), the less that information generally matters.

ThaiBoy said:

I agree with everything you have said.

Lumens, can be useful comparing lights with "exactly" the same spectrum, but since you can't get measured spectrums from LED grow light manufacturers, this don't work in practice.

In defense of Gotham Hydro, they do not know if the 2010 model, even though it has more lumens, is any better or worse than the dual band 2009 model and are doing there own grow tests now. They too are searching for that perfect spectrum!

Click to expand...

If that's the case they should not be advertising that the 2010 model is the next greatest thing & beats out all other 90w UFO's.

CaptainPointless - Some fantastic information & I thank everyone in here for getting into the discussion of this new Lighthouse Hydro 2010 High Output model. I'm strictly looking for a UFO to veg with; so this might be a decent one to look into eh?

Dr.RR said:

If that's the case they should not be advertising that the 2010 model is the next greatest thing & beats out all other 90w UFO's.

CaptainPointless - Some fantastic information & I thank everyone in here for getting into the discussion of this new Lighthouse Hydro 2010 High Output model. I'm strictly looking for a UFO to veg with; so this might be a decent one to look into eh?

Click to expand...

Based strictly on the information presented in the listing and from ThaiBoy, I would say it's a safe bet that this light will work decently for vegetative growth. However, I personally would still not pay $230 for it. I do not wish to solicit anything, but if you really want to be able to save money and get EXACTLY what you need, then I suggest taking a look at my own LED thread. It has an ongoing discussion about a manufacturer I have sourced, who is willing to be flexible with price and requirements. In addition, the company can custom build them. Less shipping, the company priced the 90W UFO-style lamps at $132 USD.

CaptainPointless said:

Based strictly on the information presented in the listing and from ThaiBoy, I would say it's a safe bet that this light will work decently for vegetative growth. However, I personally would still not pay $230 for it. I do not wish to solicit anything, but if you really want to be able to save money and get EXACTLY what you need, then I suggest taking a look at my own LED thread. It has an ongoing discussion about a manufacturer I have sourced, who is willing to be flexible with price and requirements. In addition, the company can custom build them. Less shipping, the company priced the 90W UFO-style lamps at $132 USD.

Click to expand...

CaptainPointless, I read your thread on a led group buy. Good job. I think you have done your homework and present a good deal for those brave enough to take it.

I went with Gotham Hydroponics and the Lighthouse 2009 model light because (1) the spectrum looked good based on [http://course1.winona.edu/sberg/ILLUST/lightabsorbtionbychloroplast.jpg], (2) I could get the light right away, and (3) I would have a real US company behind the product in case something went wrong. As a surprise benefit, they quickly responded to all my e-mails and shared there technical data and speculations with me.

I'm buying the 2010 model because (1) the 2009 model works great for veg thus far, (2) they presented a coherent argument as to why the 2010 model might work better than the 2009 model, and (3) they were response. After I ordered the 2010 model I learned they were actually conducting their own grow test on tomatoes comparing the 2009 and 2010 lights which is a plus too. I didn't buy the light because it has more lumens (we all know the problems with comparing lights based on lumens). On the other hand, I did want a light that had some white light because it's hard to judge the health of a plant with only red and blue light. My eyes were designed for Red-Green-Blue and damn it, I want some green to see with! Adding white light gives me some green.

I'm a subsistence farmer so I may not need any more LED lights than I have. I started with a 14W LED Grow Panel which proved the LED technology to me and led to my interest in a bigger 90w LED light. Soon I will have 2x90w + 14w (194w) which should be more than fine for a small closet.

If I were a big time grower, then cost would be a real factor and your group buy would be very appealing. Once you know the right spectrum to use, who cares who builds it so long as it's durable enough to last the LEDs projected lifespan.

Cheers!

-ThaiBoy

Here's the best single graph I've found on the web so far that shows plant reactions to different wavelengths.

http://course1.winona.edu/sberg/ILLUST/fig15-5.jpg

Very nice, nice to see you around. I see you have taken interest in the LED thread, as well as myself. Hit me up on the PM if you wanna chat about anything. See what ya have to say about all this LED goodness...

peace!

-PF-

I would add that all white LEDs are simply blue LEDs with a phosphor coating on them to change the output spectrum, similar to fluorescent lights (which are UV-->white/colors). You will always lose a certain % of the initial intensity in the conversion from one spectrum into another (in the case of white, to many others). Better to start off with a blue or a red than to add more whites, unless you're going for CRI.

Show me the research indicating there are secondary plant regulatory processes that are governed by a spectrum outside of the known blue, red, IR (dark period/heat), and possibly UV-B ones, and I'll reconsider the addition of white LEDs to grow lights.

Until then, they are simply an inefficient means of doing the same thing using better initial spectrum LEDs.

I have yet to see any LED manufacturer list their output in terms of true PAR watts instead of lumens, also.

-TL

I just got this e-mail today from my ongoing discussions with Gotham Hydro. These numbers are supposedly from the latest GrowBoys research which will be published in January.

Here's the entire e-mail, less the headers:


"My comment about the blue/uv 425nm is that technically it is not in the UV
spectrum, well the peak output anyway is not considered UV anyway. Some
output is, but the majority falls in the visible light spectrum so, that is
why I called it UV/Blue as opposed to Blue which is 450-460nm.

Next issue is addressed in the latest info we got from the engineers and
the guys at growboys. I am going to have to rewrite the listings to reflect
this. Here is the final completely engineered numbers: (to be reported in
Jan by growboys) The final postings may be slightly different but not much.
Apparently there is a Math guy doing some calculations to determine very
accurately the results based on formulas.

400w MH/HPS efficiency (when corrected for light output and action
spectrum) - 30%-34% Depending on light.
Dual Spectrum Lighthouse UV - 80% efficiency
Dual Spectrum 460nm/630nm - 70% efficiency
Dual Spectrum 460nm/660nm - 76% efficiency
Tri-Band 460nm/580nm/630nm - 60% efficiency
Quad-Band 460nm/580nm/630nm/White - 55% efficiency
Lighthouse HO 6 Band - 50% efficiency

The math is as follows:
400w MH/HPS = 20,000-35,000 lumens
Dual Spectrum Lighthouse UV - 5010 Lumens
Dual Spectrum 460nm/630nm - 4150 lumens
Dual Spectrum 460nm/660nm - 2620 lumens
Tri-Band 460nm/580nm/630nm - 4360 lumens
Quad-Band 460nm/580nm/630nm/White - 4780 lumens
Lighthouse HO 6 Band - 9450 lumens

Multiply each by the efficiency factor and you get the first calculation.

9600 (HPS) vs 4725 Lighthouse HO and 4008 for the UV model.

But you have to factor in
1) loss of lumens due to the fact that HPS uses a reflector
2) The loss of LUX because the HID must be farther from the plant.

So it is very hard to arrive at the correct numbers. Growboys is using a
LUX meter to take measurements of each at the same distance (to calculate
loss of lumens due to the reflector etc.. ) so we should at least have an
idea about that. However we must take into factor that you can put the
LED's so much closer to the plants. What is the correct way to calculate
this? A digital laser thermometer possibly?

From what we can tell, I would imagine it to fall in the range of 1 90w LED
= 240-300w HID light.

I will let you know as things develop."



The points (I think) they making here are:

(1) the 425nm is not technically a UV light, but does put out some UV on the tail end of the spectrum. This corrects an implied claim in their advertising.

(2) action spectrum based efficiencies were calculated for a 400w MH/HPS and 6 other grow lights.

(3) lumens are calculated for each light and multiplied by their efficiencies to get overall useful spectrum output.

(4) based on these calculations a 400w HPS puts out 9600 usable lumens and a 2010 model puts out 4725 usable lumens and the 2009 model puts out 4008 usable lumens.

(5) AND THIS IS THE BIGGEST POINT OF ALL: a good spectrum 90w LED grow light is equivalent to a 240-300w HID light.


Now we have some evidence that a 90w grow light has equivalent growing power to a 240-300w HID light. THESE ARE THE FIGURES THAT SHOULD BE USED AND ANYONE SAYING A 90W IS EQUIVALENT TO A 400w HID BULB IS NOT BASING THE CLAIM ON ANY JUSTIFIED CALCULATION.

As a community, we need to be honest about what LED grow lights can and can't do and stamp down any unjustified claims! These calculations can be done for ANY LED grow light. Perhaps the community should DEMAND a standardized rating system based on the action spectrum. Perhaps the term "usable lumens" should precisely mean the results of these spectrum based calculations.

Kudos to Gotham Hydro for trying to set the record straight!

I hope this helps inform the LED grow community.

-ThaiBoy

i recently bought a led panel that uses 14w on ebay but says the eq is to a 250w hps for 36 dollars!!!

T@ll T33 said:

i recently bought a led panel that uses 14w on ebay but says the eq is to a 250w hps for 36 dollars!!!

Click to expand...

If you are serious, then I'm sorry but, LOL!!

<====New to site:

So I recently switched over to two 90W LED UFOs and am well into my third week of flowering. So far they seem to be working just as well as my old HPS. I've already seen a reduction in my electricity bill and I no longer worry about the temperature in the grow room. Unless something happens from now until harvest, I can safely say I'll be an LED grower for life!