Anyone using LED grow light?

[ALToronto]

Not as much as it look in this photo though, it does have a purple tint. I don't mind it because it's every bit of energy that my plants can actualy use. It's possible to add a regular white light in there to help but it's wasted energy for our own eyes

That's not really true. Plants do benefit from a broader spectrum. The UFO lights were developed for large scale cannabis growers, who grow the plants as annuals. They're concerned only with the year's harvest, not the longterm health of each plant. So just like with fertilizers, we cannot imitate the regimes of commercial growers, who need to bring their plants up to blooming size as quickly as possible.

So even though you are likely to see a short-term benefit from the red and blue lights, I wouldn't want to keep them lit exclusively this way for 5 years or longer. My best growing plants are in a south-facing window. My second best growing plants are lit with a combination of 5000K and 3000K 5W LED's.

 

[daniella3d]

Any info on what you are saying? where did you get that? Are you telling me that people cannot grow orchids on the long term with artificial light?

The UFO light I am using has blue and red but also other wave like IR, UV and some green, it's not just blue and red. Also it is supplemental light because my plants are located right beside a ouest facing window so they do get natural sunlight, few hours per day, shaded with a curtain.

So what are you going to do with your plants under LED? how long do you have them growing with LED?

That's not really true. Plants do benefit from a broader spectrum. The UFO lights were developed for large scale cannabis growers, who grow the plants as annuals. They're concerned only with the year's harvest, not the longterm health of each plant. So just like with fertilizers, we cannot imitate the regimes of commercial growers, who need to bring their plants up to blooming size as quickly as possible.

So even though you are likely to see a short-term benefit from the red and blue lights, I wouldn't want to keep them lit exclusively this way for 5 years or longer. My best growing plants are in a south-facing window. My second best growing plants are lit with a combination of 5000K and 3000K 5W LED's.

 

[daniella3d]

I bought 2 andean tears they had on their list, plus one china dragon. Can't wait

The Andean Tears are seedlings but at least they are not too expensive to try. The China dragon is BS and 70$.

I will pick them up at the show in October. How does it go when you order for a show, do you pay up front or do you pay when you pick them up at the show?

I only know two people that were successful flowering the Andean Tears...
and I'm not one of them, ... But it's still worth the try. Amazing and huge flowers.
Peruflora has it listed for 30-35 dollars (to bloom in two years ...so I guess it means large seedling).

 

[BLReed]

You might want to consider these. My understanding is that they replace T5 and T8 in fixtures with an electronic ballast. Not magnetic ballast.

http://www.hortamericas.com/catalog/horticultural-lighting-led-lights/GreenPower-TLED-DRW-18W.html

Here one Link to a YouTube video

http://www.youtube.com/watch?v=L_Ya9wDMdUA

and another

http://www.youtube.com/watch?v=u8-FKHAVsnA

 

[daniella3d]

Strange, they write ''Call for price'' There is no info on how many led there are in their tubes, could be just 1 watt diodes? I see 30 watts or so per tube.

No clue what is the price on those and you still need to have a T5 fixture which I don't have and that can be expensive.

I might just go with the DIY LED kit.

You might want to consider these. My understanding is that they replace T5 and T8 in fixtures with an electronic ballast. Not magnetic ballast.

http://www.hortamericas.com/catalog/horticultural-lighting-led-lights/GreenPower-TLED-DRW-18W.html

Here one Link to a YouTube video

http://www.youtube.com/watch?v=L_Ya9wDMdUA

and another

http://www.youtube.com/watch?v=u8-FKHAVsnA

 

[Bjorn]

Its a common misconception that plants do not need green light. They do but do not utilise it to the same degree as the red and blue. That is why they appear green. You might benefit from looking at this site
http://www.heliospectra.com/
and even better to look into this paper
http://www.heliospectra.com/sites/default/files/general/What light do plants need_5.pdf
Heliospectra is a company that specialises into LED Equipment for research, so their equipment is beyond (financial) reach of most of us..

 

[daniella3d]

Interesting paper. But there are some green light in my UFO lamp, and some IR, it's not only 2 bands, one is 8 bands full spectrum and the other is 10 bands full spectrum. It's very much geared for plant photosynthesis, not human benifit, so I don't see why it would have any long term negative impact in the plants.

I keep reading conflicting info about this green spectrum...here is a thread you migth want to look at:

http://www.slippertalk.com/forum/showthread.php?t=31426

http://pcp.oxfordjournals.org/content/43/6/639.long

Its a common misconception that plants do not need green light. They do but do not utilise it to the same degree as the red and blue. That is why they appear green. You might benefit from looking at this site
http://www.heliospectra.com/
and even better to look into this paper
http://www.heliospectra.com/sites/default/files/general/What light do plants need_5.pdf
Heliospectra is a company that specialises into LED Equipment for research, so their equipment is beyond (financial) reach of most of us..

 

[ALToronto]

Any info on what you are saying? where did you get that? Are you telling me that people cannot grow orchids on the long term with artificial light?

The UFO light I am using has blue and red but also other wave like IR, UV and some green, it's not just blue and red. Also it is supplemental light because my plants are located right beside a ouest facing window so they do get natural sunlight, few hours per day, shaded with a curtain.

So what are you going to do with your plants under LED? how long do you have them growing with LED?

Daniella, the LED's I use are broad spectrum white light. 5000K is closest to pure white, 3000K is a warmer white with more red. So the combination of these lights gives a very good approximation of sunlight.

I was talking about the red/blue UFO lights when I said that I wouldn't want to grow plants under them longterm. They're ok as supplementary lights. But now that LED technology has improved so much for broad spectrum white lights, I would not consider the UFOs even for occasional supplementation.

 

[Bjorn]

Interesting paper. But there are some green light in my UFO lamp, and some IR, it's not only 2 bands, one is 8 bands full spectrum and the other is 10 bands full spectrum. It's very much geared for plant photosynthesis, not human benifit, so I don't see why it would have any long term negative impact in the plants.

I keep reading conflicting info about this green spectrum...here is a thread you migth want to look at:

http://www.slippertalk.com/forum/showthread.php?t=31426

http://pcp.oxfordjournals.org/content/43/6/639.long

It is probably possible to grow without green light, but personally I have always believed that making the conditions as close to nature gives best results. And so far.....the sun is not yet red:evil:
For many species I believe I have good results

 

[naoki]

I think Alla's initial statement is an overstatement (e.g. analogy to fertilizer). If you look at the fluorescent light, many of them (cheaper ones) have really narrow spectra (major 3 peaks because of phosphor emission peaks). Many people have been using it for a long time. It is true that we are still discovering the basic plant physiology. Currently, we know that plants have sensors to detect red/far red, blue, and UV. And it's likely that more "eyes" of plants will be discovered in the future.

There are two aspects about how light quality (spectra) influences plants. First, these light sensors are used to "see" the environmental change, and plants use these cues to change their morphology and life cycle (examples: photomorphogenesis such as etiolation and photoperiodism such as timing of flower, which isn't so relevant to many orchids).

Then the other part is photosynthesis. Plants can grow only with red light (or blue light). Initially red light was used, but then blue light was added to reduce the etiolation. Then other different wavelengths are added, and people are trying to optimize the horticultural light. A part of the goal is the highest photosynthetic reaction per given electric energy, but the other goal is to control the growth pattern (photomorphogenesis part). As Bjorn pointed out, it was recently shown that green light can have significant effect of photosynthetic rate under "strong" light. It is hypothesized that when the cells near the surface is receiving more light than the system can handle, additional green light can penetrate deeper into the lower layers of cells, and drive photosynthesis at the deeper level. It is not known if this is the case for lower light plants like orchids. People are optimizing horticultural light, but I think that it is unlikely that a single spectrum is best for both corns and orchids.

Bjorn, something closer to sun is probably a safe bet, but with artificial light, I think that there might be an electronically more efficient spectra (no data).

With regard to the stomatal control by blue/green light (the older thread), it doesn't mean that the green light will slow down the photosynthesis rate, though (at least, I haven't seen that part of the data). The stomata of Paphs are unique among plants, so there are quite a few interesting studies of Paph stomata.

 

[daniella3d]

Ok but is there a study saying that those bleu and red UFO light are bad long term? what makes you say that it's not good to use them long term? they do have green, IR and a few other bandwidth, and you can even add UV (I did not). Nowaday these lights are not only red and blue, they have come a long way. And they are not 1 watt diodes anylonger, at least the good ones. I use a 180 watt with 3 watt diodes. So maybe the initial only blue and red might not be good long term, but I don't think this apply to the new full spectrum LED.

As for using the 5000k light, is it really better for the plants? I would really like to see the study comparing this and showing the effects long term. Is it aviable?

Daniella, the LED's I use are broad spectrum white light. 5000K is closest to pure white, 3000K is a warmer white with more red. So the combination of these lights gives a very good approximation of sunlight.

I was talking about the red/blue UFO lights when I said that I wouldn't want to grow plants under them longterm. They're ok as supplementary lights. But now that LED technology has improved so much for broad spectrum white lights, I would not consider the UFOs even for occasional supplementation.

 

[Silvan]

I was wondering what does COB (?chip on board?) means ?
And is (example) a 100w COB is more "intense" than a regular 100w LED ?

 

[naoki]

Daniella, here is a somewhat related poster: http://cpl.usu.edu/files/publications/poster/pub__2576523.pdf
Even though it is using lettuce, there are several interesting aspects. However, it doesn't talk about the long-term effect, which you are asking about (it's unlikely that red+blue is detrimental/harmful in a long term).

Silvan, yes, COB is "chip-on-board". I don't pretend that I understand why it is better. I have read a couple things, but my understanding is that it can manage the heat better (heat is bad for efficiency). A couple related links:

http://www.digikey.ca/en/articles/t...duce-cost-and-save-energy-in-lighting-designs
http://www.cob-led.com/COB-LED-Advantage-Chip-on-board.html

It is difficult to say 100W COB is more intense than non COB. There are lots of variations in LED efficiency. Higher efficiency of COB is probably true if you compare COB against older generations of non-COB (like so-called 1W or 3W LEDs). However, it may not be the case with the newer non-COB. With non-COB LED, I think Cree XM-L2 has one of the highest efficiency (white LED). It is rated at 10W max. I haven't done the comparison for a while, but if you compare 10x XM-L2 vs 1x CXA3070 (rated at 117W max), I think XM-L2 gives slightly more output for a given energy consumption. However, XM-L2 was at least 2-3x more expensive, I believe.

A brief reminder of the "watt" ratings of LEDs:
When people says 3W LED, it CAN handle up to 3W. But most of the time, we drive them at much lower current (e.g. to consume 2W) for the increased efficiency. This is a part of the reasons I'm running CXA3070 at 50W. To cover 8 sq.ft., I could get 2x CXA3070 at 50W or 1x CXA3070 at 100W (initially cheaper, but you aren't getting as much light as 2x 50W). So it's a balance between long-term vs short-term (initial) cost.

The other reason I like COB for DIY is the ease of assembly. Instead of attaching 10-30 diodes, you can put 1 chip. However, there is a counter-side. COB becomes more of a "point-source" light. This means that the lower leaves can be shadowed by upper leaves. When you have a bigger LED panels like yours, more light can reach to the lower leaves.

Sorry for a long reply, but please keep us updated with how aquarium (bluish) light will do with orchids!

 

[naoki]

I was wrong that XM-L2 is slightly more efficient.

It might be a bit tricky to understand how to use this tool, but this is a interesting tool to compare different Cree LEDs.

http://pct.cree.com/dt/index.html

To get the same efficiency of CXA3070 at 50W, you need to run XM-L2 at very low current, and you need 43 of them to get equivalent amount of light (so $40 of CXA3070 vs $250 of XM-L2). Alternatively if you compare the light output of 1x 50W CXA3070 vs 10x 5W XM-L2, you can get 33% more light from CXA3070.

The tool reports only lumen and not PAR (PPF), so we can't compare white LEDs vs monochromatic LEDs (e.g. red, blue).

So to Silvan's question, yes, COBs (at least high-end) seem to be more intense (most of the time). But not all COBs are created equal. My testing, which I posted here previously, showed that ebay Chinese COBs have much lower efficiency, and not worth getting them.

Then Cree has so many different LEDs, and really confusing. Here is an explanation of different product line (COB is not included):
http://flashlightwiki.com/Cree

 

[ALToronto]

Ok but is there a study saying that those bleu and red UFO light are bad long term? what makes you say that it's not good to use them long term? they do have green, IR and a few other bandwidth, and you can even add UV (I did not). Nowaday these lights are not only red and blue, they have come a long way. And they are not 1 watt diodes anylonger, at least the good ones. I use a 180 watt with 3 watt diodes. So maybe the initial only blue and red might not be good long term, but I don't think this apply to the new full spectrum LED.

As for using the 5000k light, is it really better for the plants? I would really like to see the study comparing this and showing the effects long term. Is it aviable?

We're on the bleeding edge here with lighting plants that need to stay healthy longterm. Any studies available are for crop plants, which are grown as annuals. Even if someone wanted to fund a study of the longterm effects of artificial lights on perennial decorative plants, there wouldn't be enough data available right now, because the top of the line LED's we're using haven't been around all that long. So we don't even know how well the lights themselves will perform longterm.

We're all running our own little experiments, whether we realize it or not.

Naoki, when I bought my LED's (COBs from China; not Cree but seem to be quite good), I asked for spectral graphs of the light output of each temperature, and there was enough flux across the spectrum to make them fairly broad spectrum, rather than trimodal. Yes, they did have distinct peaks at certain wavelengths, but the peaks were not very sharp. The plants seem to like them - I'm getting very good growth on my Catts, and the anthuriums in the s/h catch basin will have to go soon - they're getting so tall, they're shading the orchids on the lowest part of the wall. And this is since April.

My earlier living wall, lit with Ray's rectangular LED lights (which are much more blue than my 5000/3000 K mix), has great vegetative growth, but no flowers. Maybe it's the lights, maybe it's the fertilizers. Maybe it's not enough light. This one's just over 1 year old.

 

[daniella3d]

So I would be better of going with cool white and neutral white CREE led and build my own kit, rather than buy a 8 bands UFO lamp. I am looking at www.rapidled.com and they have pretty much everything. I just with there was something already build for not so expensive.

They do have full fixtures for growing but they are limited to either cool white or neutral white, not a combinaison of both and they are expensive. Not in my budget. Maybe PAR 38 buld would work, not sure?

 

[Silvan]

really cool website Daniella. They have everything. Even T-Shirts! lol
One very cool product they have is the housing for DIY projects for $70.
Not having the casing was what stopped me from trying. I'm no electrician.

please keep us updated with how aquarium (bluish) light will do with orchids!

I will! Right now I find the leaves of my plants to be a bit too light green. It could be that the days are too long, the wattage is too high or that in overall
my plants are starting to be fed up with summer temps. But they are growing. I have to add that I mostly grow phragmipedium under this particular fixture.
I might add some paphs in the near future. But my paphs are really doing great under the 140w. LED fixture. So I might have to buy new plants to try it out..lol

Doing a bit of research I found the disposition of the colors on my 140w system. I really have to print that page..
http://www.aliexpress.com/store/pro...amp-Free-Drop-Shipping/224261_1696100481.html

Like Naoki said. The Cree led seems to only be in the center on the module :
http://www.aliexpress.com/item/Heli...pcs-High-Power-Led-Plant-Grow/1793675362.html

 

[daniella3d]

Yes cool site, mostly oriented to reef aquarium, that's how to got to know it, but they do have led for plants as well and the case can be used for plants as well.

I am thinking maybe mixing some warm and cool white and put them on their oxyn case. Sounds like fun project to do with 5 w led.

really cool website Daniella. They have everything. Even T-Shirts! lol
One very cool product they have is the housing for DIY projects for $70.
Not having the casing was what stopped me from trying. I'm no electrician.



I will! Right now I find the leaves of my plants to be a bit too light green. It could be that the days are too long, the wattage is too high or that in overall
my plants are starting to be fed up with summer temps. But they are growing. I have to add that I mostly grow phragmipedium under this particular fixture.
I might add some paphs in the near future. But my paphs are really doing great under the 140w. LED fixture. So I might have to buy new plants to try it out..lol

Doing a bit of research I found the disposition of the colors on my 140w system. I really have to print that page..
http://www.aliexpress.com/store/pro...amp-Free-Drop-Shipping/224261_1696100481.html

Like Naoki said. The Cree led seems to only be in the center on the module :
http://www.aliexpress.com/item/Heli...pcs-High-Power-Led-Plant-Grow/1793675362.html

 

[naoki]

Alla, it's great to hear your plants are getting good growth! I was talking about florescent light which has sharp emission peaks. You are correct, the white LEDs have wider spectra with 2 major peaks (unless it is RGB style white LED). The white LED is basically blue LED, and blue lights excite the phosphor coating to create green and red light (so it looks white).

Daniella, I've never bought from them, but RapidLED could be convenient because they have lots of stuff. But the price is usually quite a bit higher. Are you talking about Bloom Onyx (the prebuilt one)? It looks interesting. After looking the spectra of different color temp LEDs, warmer one seems to match better with photosynthesis (warm white, 2700-3000K). That's what I usually use. But some grow light company uses 4000K. In theory, you need to have more phosphor for warmer color, so number of photons could be lower in warm white (due to some loss from phosphor). However, if you look at the efficiency of photosynthesis (called action spectrum), red light is more efficient than blue light. So it is difficult to say which one (warm vs cool white) is better.

When I measured PAR of chinese 100W LEDs, cool white and warm white had similar PAR (I don't have the number at this moment). So the loss due to phosphor is probably not big, and warm white with more red could be a bit more efficient.

Similarly, you don't want to use higher CRI white LEDs (thick coating and reduced overall output).

Silvan, but the page said the other diodes are Bridgelux (they make good LEDs). I didn't know Bysen-type grow light was using Bridelux for the other diodes.

 

[Ray]

Naoki - when I was developing the chip mix for my 13W lamps, I compared spectra of warm and cold white chips - the "warm" ones did not have "more" red, they had less blue.