LED grow lights

[greenlight]

Power meets efficiency
with LumiGrow ™ LED grow lights.

Go Green. Save Green.
Indoor gardening experts select LumiGrow LED grow lights to protect plant health, save money and reduce carbon footprint.

This might be worth checking out just to see what else people are using. I talked to the owner, he says he uses 5w luxeons because he can get them for a good price and they put out a lot of light.

 

[Oznog]

This might be worth checking out just to see what else people are using. I talked to the owner, he says he uses 5w luxeons because he can get them for a good price and they put out a lot of light.

And that's probably an example of a mfg with a problem. Sounds like he's selecting based on visible lumens rather than PAR, which is a mistake. Granted I don't have experience trying this growing yet, then again many of these people are simply saying "it grew things" without a controlled experiment to show what grew better than something else. I believe the PAR charts are important here and that shows the value is in Deep Red.

 

[ALICIA21]

Yeah actually green is the wavelength the plants DON'T need. If they used it, it would be absorbed not reflected. It is unproductive to generate these wavelengths, it's wasted power and heat generation at the light and some of it will be turned into heat at the leaf. I know IR would just be dissipated as heat at the leaf and shortwave UV is surely damaging to the tissue not helping.

There are a bunch of charts showing there's two peak centers of usage, one in the blue range another in the red-orange. Apparently both are needed, there are descriptions of how the balance serves different biological functions and makes them grow vs flower or something but so far the pages sound like pseudoscience- trying to sound scientific in the lack of any actual data or scientific understanding. Basically speaking out of their asses.

Wikipedia says photosynthesis uses only 2% of the visible spectrum then "[citation needed]". Well, if one could give it only what it needed with LEDs that could in theory make LEDs a far superior choice. But this is Wikipedia.

I'm also unsure of whether a couple of tight bell curves at the red-orange and blue ranges will actually serve all the biochemical needs. The usage graph shows SOME absorption in other wavelengths... I wonder if they're essential biochemical steps of the photosynthesis process which would fail without small amounts of these wavelengths?

There are a bunch of charts showing there's two peak centers of usage, one in the blue range another in the red-orange.

 

[Cactus Bastard]

There are a bunch of charts showing there's two peak centers of usage, one in the blue range another in the red-orange.

Yes, that's what we've been talking about actually

In theory if we could meet like 4 key spectral points, you could grow on a tiny fraction of the power since the process is so unresponsive to all that stuff in the middle.

Another factor to consider (with regards to PCs at least) is that LEDs put out lighting that is actually constant . Fluorescents flicker at varying frequencies above what the human eye can detect, in order to provide what appears to us as consistent lighting. A plant does not have any complex optical system smoothing out the lights for them. They are simply absorbing the raw energy.

the 100+W high power LED ones perform really really well on most plants. They seemed to have problems with cucumbers though...

That concerns me a bit.. Different spectrums will affect different plants differently. Also, the whole thing about how they affect things is a confusing issue as well. How some plants have adapted to associate differing lighting conditions with different forms of competition from neighboring plants..

Also, I strongly agree that even when using LEDs to fill in the key spikes, a smaller fluorescent tube filling in some of the other wavelengths could be very beneficial indeed.

 

[Torbeam]

Take a look at these

I will make an attempt next season with 10 different chilli peppers!

 

[Oznog]

Take a look at these

I will make an attempt next season with 10 different chilli peppers!

]

That's the common 640-660nm red. It has the same problem as all the other "normal" reds discussed here- it misses the 680nm response peak (only hit by "deep red" devices) and I don't think it's gonna be a very good performer.

 

[thegeek]

This place has some 680nm emitters in relatively high power packages, they have a minimum order though.

http://www.tech-led.com/High_Power_Illuminators.shtml

If someone were interested enough to do a group buy I would be in for a couple. I just don't have the ambition or time to run one myself.

 

[Oznog]

IIRC the tech-led is really expensive and seems to be an old, off-brand tech.

LEDEngin seems to be best supplier of Deep Red, Mouser carries them which makes them vastly easier to get and the price isn't too bad. The problem is the nonisolated thermal path.

 

[Julius]

Of course the produce was probably completely tasteless like everything else in the Dutch supermarket.

I had to register for this forum if only to respond to this bullcrap statement.
I've never been really fond of living in The Netherlands, I have not been born here and both my parents migrated out of the NL ages ago. For long periods of time I've stayed in Thailand, Cambodia, China, Malaysia, several places in Afrika, Canada, The US, The UK, Germany, France, Italy, Belgium, Jersey Island, Tenerife, Serbia-Montenegro, Russia and Norway, but never ever did I encounter better tasting Supermarket content as there is available here in The NL!

Now, of course your taste can be your taste alone, but to claim 'everything' is tasteless in Dutch supermarkets sounds to me like you either have never been in one, or didn't develop the power of taste, because truely, that claim is utterly ridiculous and false.
Here in Amsterdam I can buy practically *every* available taste that exists in the world in countless supermarkets, and all pretty near to where I live, even. In addition to that, most average Dutch supermarket food has much more taste than what you'll ever find in other countries. The chocolate and snacks alone are the best you can find worldwide.

Furthermore, the cheese available in Dutch supermarkets is the best tasting cheese one can find, by far. You won't find anything remotely close anywhere in the nations and areas I mentioned above, including the US. Even Dutch goat-cheese tastes much better than the French one, who claim to be king at that.

I've never been one to defend the country I live in, but what you state there is a pure misplaced lie. You probably assume all Dutch citizen use drugs and wear wooden shoes too, right? Kind of like the Fox News idiocracy you suffer from in the US. [moderation: abusive comment removed. - DM51]

 

[DM51]

Welcome to CPF, Julius.

We'll allow you your patriotic (but off-topic) rebuttal of snarfer's post, although you might want to note that he posted it ~18 months ago, and you've just resurrected a somewhat obsolete thread. It's sometimes worth looking at the date of these things before you reply to them.

What we can't allow, however, is the last sentence in your reply. You may attack the post, but not the poster. Please would you therefore edit your post to remove that sentence.

The thread may contrinue on condition that it returns to discussing the topic, with no further distractions...

 

[blasterman]

I just want to jump in an rehash my skepticism over the need for far red (>640nm) LEDs with growth lights.

Reason for this being that the proven benefits of HPS and the orange/pink spectrum of that light source would seem to contradict the need for far red.

As for the rather heated side-bar that Julius responded to, I live in West Michigan which has a huge Dutch population and culture, and there are countless Dutch run produce stores and eateries close to my home. I wouldn't call Dutch tastes 'bland', but they do emphasize dairy/white grains over spices, etc., and this I think tends to contribute to the opinion of ethnic Dutch food as being rather blah to other tastes. A better term would be 'practical'. The Dutch owned dairy I was in last year was white wash clean and vastly more humane that the horror stories you see on the news.

 

[Kevinwells]

Hi,
this is Kevin from LumiGrow. I saw your posting and I thought I would talk a little about your last comment re red/orange and hid lighting.....

We released the first version of our product using 640nm peak red LED's. One year later we upgraded the LED's to 660nm LED's and the difference was night and day.

We dramatically improved the performance of our light. some of that was just adding more LED's (we added about 40 watts of white to help users see their plants ) But the real difference was the red.

We had our light independently tested. UC Davis did the plant growth tests. They found the light performed equally to a 600 watt HPS in a greenhouse.

We also did spectroradiometric testing and compared it with an Eye Hortilux 600 watt HPS bulb. Our light had 10% more blue and 3% more red at 660nm.
In contrast, our original model using the 640nm led's had about 30% less red at 640nm than the HPS. (HPS lights have a high yellow orange content)

We continuously run tests in our labs. They have shown that it is not just the red, but the wavelength of the red that matters. The same light, with 660nm LED's, produces about 45% more flower buds than the 640nm peak wavelength LED's. Our test plant was Chrysanthumums, a sun loving, short day obligate plant. Our tests using lettuce, showed no real difference but lettuce is less sensitive to red...
I hope this helps clarify the subject.

 

[thepaan]

Plants have two photosystems (PS): I and II. They also have two major chlorophylls (chl): a and b. PSII contains mostly chl b where PSI contains mostly chl a. PSII uses light energy to free electrons from water and feeds them to PSI. When one PS is stimulated less than the other (below light saturation) then it becomes the limiting factor in photosynthesis. When PSII is the limiting factor the system is relatively stable but when PSI is the limiting factor then the electrons in PSII get backed up and eventually damage the PSII D1 protein.

To answer a question several posts up: chl a and b both have a peak in the blue and the red. Although the blue peak is usually shown as higher than the red peak, the red peak is much better at driving photosynthesis.

The difference in night and day between your 640 and 660 nm LEDs is because with the 660 you have a better balance of light between the two photosystems. Though, I would still like to see an LED grow light with two red wavelengths - one at 650 and the other between 670 and 680, with a ratio between 1:3 and 1:6 former to latter.

 

[Julius]

Hmm.. my measurements and research shows me that the two major frequencies (where you want the peaks to be at) are 428 nm and 664 nm, for underwater plants anyway.
The rest of the spectrum will easily be fed from simple cheap white and warm white LEDs, and aren't really much of an issue if you ask me. Most artifical plant-growth lighting situations will already have those areas from the spectrum in sufficient amounts around, I would guess..

 

[Julius]

I found an interesting thread:
http://www.thekrib.com/Plants/Tech/lighting.html
saying that the color of light does not have more than 10% importance (where 100% is the total lighting for freshwater aquarium tanks).

In 1982 Philips Corp. did a lot of experiments in order to find out the effects of different light colours on aquarium plants. The following plants were used (because of their fast growth):
Hottonia inflata
Limnophilia sessiflora
Ludwigia natans
Bacopa amplexicaulis
Hygrophilia polysperma
Rotala macandra
The surprising results were that the influence of colour was less than
10 percent!

5) The results are applicable for all aquatic plants because all aquatic
plants
contain the same type of chlorophylls as the land-based plants.
Algae contain additional chlorophylls that are not found in higher plants.
From McCree's experiments it is obvious that these additional chlorophylls
are responsible for the sensitivity to blue light.

Bottom line:
============

It does not matter what colour of light you provide for your aquarium
plants. Choose a colour that makes it look good for you.
If you are not interested in algae (fresh water people usually are not)
you can additionally try to avoid the blue part of the spectrum
(or keep it to a minimum). This also means that high light temperatures
(>5500K or so) are better suited for a salt water aquarium.
---> Your mileage may vary.<---

This contradicts my personal findings quite a bit.
My experience clearly shows that, for example, the famous plant Cabomba, thrives under the blue 428 nm peak, and even searches for it. When I noticed this, I tried the same on other plants, and practically all showed similar results. They *want* the 428 nm to be there, preferably lots of it.

If anyone knows more about this, I'd be happy to know what others experience.
I wonder how these experiments by Philips from 1982 were executed. Did they use color-lense-filters, or actual colored sources of light?

 

[blasterman]

I would still like to see an LED grow light with two red wavelengths - one at 650 and the other between 670 and 680

I just blast lost of energy at 615-625nm, (70/30 red/blue at 460nm), and have excellent growth for everything. Same analogy as HPS, which is a known working technology devoid of far red.

Maybe we should get loudspeakers and tell the plants on repeated loop they should respond to wavelengths we determine in the lab, not in an actual commercial greenhouse

 

[Inkidu]

greenhouse ------------artificial lights

Two things that have next to no relevance to each other.

That is to say I never walked into a local greenhouse with lights in it.

The whole point is you take advantage of the sun to grow your plants.

A large commercial greenhouse that use artificial light (hps) I would assume do so for

very specific reasons. The spirit of the thread is are leds a viable solution in a small aeroponics application.

And one main reason they could be considered for a person trying to grow a few plants

in there house is the cost and trouble of trying deal with the heat that HPS and MH produce.

Here is another way to say it just because what ever is used to make a Mcd........ burger

works for them doesn't mean it works for me in my frying pan.

Hope this helps.

 

[Inkidu]

What importance if any can be given to the CRI #. (for growing)

Seems to some extent that a grower would want to simulate

natural sunlight as much as possible. Whether that is the most

efficient thing is another ? (colored leds) I have been eyeballin

http://www.tech-led.com/data/SMB660N-1100-01.pdf

They also mention a 680nm but the radiant power falls off

and the power put into is quite a bit different compared to the 660nm

version. Efficiency is always a concern for me.

http://www.tech-led.com/data/SMB680-1100-I.pdf

Anyone order from this company?

Thinking of, to save money, mounting them on top of a small piece

of copper or al with insulating epoxy. Just big enough for the heatsink

portion of the led. I am fairly new to this but isn't this how some flashlight

leds are mounted i.e the heatsink pad is epoxied and the overhanging leads

are connected?

Would I want a ceramic pad between the led and heatsink both options

are available from this company i.e. the I suffix is added?

I am far from an expert so any help would be appreciated.

 

[kaichu dento]

greenhouse ------------artificial lights
Two things that have next to no relevance to each other.
That is to say I never walked into a local greenhouse with lights in it.
The whole point is you take advantage of the sun to grow your plants.
A large commercial greenhouse that use artificial light (hps) I would assume do so for
very specific reasons. The spirit of the thread is are leds a viable solution in a small aeroponics application.
And one main reason they could be considered for a person trying to grow a few plants
in there house is the cost and trouble of trying deal with the heat that HPS and MH produce.
Here is another way to say it just because what ever is used to make a Mcd........ burger
works for them doesn't mean it works for me in my frying pan.

First, welcome to CPF!

The reasons for using lights in a commercial greenhouse, or any greenhouse for that matter, is to maximize growth on cloudy days, to extend the growing season and assure the plants are getting the light they need early and late in the day.

For growing indoors without the benefit of a greenhouse makes it even more important though!

 

[Inkidu]

Thanks for the greetings.

"For growing indoors without the benefit of a greenhouse makes it even more important though!" You are joking with me right?

So I need lights indoors.

How does anyone use LED as an indoor grow light?

I don't know it this helps Oznog but I am trying to figure out the same thing

as far as if colored led can have benefits as far as being more efficient than

white light. Personally I am leaning towards a high power mixture.

I am trying to use a combination of warm white led and deep red led.

My present application is of all things to grow algae as a filtration method

for a fish tank. As a general statement I am sure that input would help for

any type of plant that you are trying to grow under led lights.

My particular application has been shown to do well

with light that emphasizes the red spectrum.

I am presently building a setup with ledengin 660nm and Marubeni 680 nm

with cree warm white xp-g and xp-e 470-480 blues (the blues fill in where

the warm white cree spectrum falls off)

I personally believe, that while it might be difficult to use generalities about

what led lights are effective, a productive discussion can be made about

what LED work 1st hand for anyone trying to use a LED indoors.

Hope this helps and would appreciate a productive discussion on what

LED work to grow plants indoors.

Thanks for any help.