new Led lights
 

Hello, is there anybody who is already triyng this kind of ligths?
Orchid Web: LED Wide Spectrum Grow Lights
I live in Italy and they are still not available here. Before making an overseas order, I would be glad if someone could tell me something more about them (can they be used as a lonely source of light for orchids? What is the max distance suitable between lights and plants? Are they comparable to a 150 W MH?).
I saw some chinese Led lights for indoor gardening some year ago, but friends tried them and they were not performing: plants didn't grow or grew stunted.

I didn't want to be reporting too early on this, but I have converted my entire indoor basement plantroom to LED lights from Orchids Limited. I consider this a major experiment (and investment) that needs a detailed results explanation later. I have 6 of the BR30 15w 60 degree bulbs, 4 of the BR30 15w 120 degree bulbs, and 13 of the MR16 7w 38 degree bulbs in action. All of these are the Natural white type, which maximizes the chlorophyll a light absorption. What you use depends critically on how much height you want to achieve over the plants. The MR16 need to be about 30 inches over the main growing zone, the BR30 60 degree about 18 inches, and the BR30 120 degree about 6 inches. All of these heights will supply a 21 inch diameter circle with a single bulb. In these circles, the MR16 will supply 246 fc (2.648 lux), the BR30 60 degree will supply 261 fc (2,804 lux), and the BR30 120 degree will supply 735 fc (7,910 lux). Obviously, when you overlap the bulbs, as I do, you have many zones with approximately double these values, which we think will be plenty to grow almost everything. There is almost no heat generated by the lights and I am using only 20% of the wattage I was before with fluorescent and compact fluorescent lights. I think the investment will pay for itself in about 2 years with electricity savings and bulbs savings, since these LED lights are good for probably at least 8 years.

Enough for now. Now we see how well things grow and bloom. The color really is natural white so colors are true. For the first time ever I have nice headroom and can have Phals and Phrags blooming under the lights with still good intensity reaching the leaves.

Of course, like every experiment, everything could also die. I just like change.

In my opinion you'd be better off going with t5's .Because of the heat spectrum and the amount of light they put out . unless your growing on shelfs and have the lights right on top they really don't work that well . If your looking for a more cost efficient way of light you might as well try the new induction lighting , they have the same spectrum as a MH and just as good as intensity as most HID's with way less heat and half the wattage. NO i don't sell these but i would put money on that they are the next best light. led's are a over rated light unless your using them for a flash light.

Here are the facts on induction lighting.
http://www.warehouse-lighting.com/pd...son%5B1%5D.pdf

Here is also a good artical on LED's and it compares most lights and led's read and see if they are really worth the money.
Myths Busted, LED Lighting

terryros - please keep us updated on your progress.

eric - interesting links..any data out there with these used as grow lights?

I'm the process of building a grow light system using Cree XP-G R5 LEDs and 60 degree optics, which are 3w each with a lumenal output of over 130 lumens/watt. The people who do aquarium keeping have been using these as well as the earlier XP-Es for a while now, and get good growth (obviously with different spectra). I can report here my progress if anyone is interested!

From my reading (and this isn't from personal experience), the low wattage LEDs are not too great, which is why I'm interested to see how these orchidweb lights will do. Also, I feel like the lights in the video are really far from the plants...I am curious whether they have actually done LED-only grow experiments, or simply used these as supplementation.

There's some really awesome experiments found in various online forums looking at PAR (photosynthetically active radiation - the light that plants use) measurements with LEDs which I'm too lazy to dig up and post...but it might give a better idea of whether the lights are actually decent. From my (brief) online research, around 300-400 umol/m2/sec of PAR is decent...but someone should correct me if I'm wrong.

The footcandle/lux data that I cited comes mathematically from the company literature for the specific chips that I am using. The Natural white bulbs have peak spectrum that corresponds to 644-828 nm wavelength, which covers an important part of the chlorophyll a absorption spectrum. Chlorophyll b absorbs light, but passes this to chlorophyll a, which is the direct photosynthesizing substance.

Many standard light meters have an absorption peak at about 590 nm, so measurements with these are not accurate under certain types of lights.

The lights I am using (7W and 15 W) are much brighter than previous ones. Unless the company data are false, achieving anywhere from 250 to 750 footcandles with this wavelength for an appropriate amount of time during the day should give very nice growth.

With the use of fluorescents and compact fluorescents, I had too much heat in my room. That is now solved. When looking at costs, you not only have to consider electricity, but also replacement costs of bulbs. The BR30 bulbs are rated at 40,000 + hours, which for me would be about 8 years. I would have replaced any type of fluorescent bulb multiple times over that time period. Finally, I don't think I could put any fluorescent fixture 30 inches above the key growing area to accommodate spikes and still have adequate illumination for the plants. Thus, I think I have gained headroom I couldn't get before.

For what it's worth, if you're currently growing plants well under artificail lighting, you shouldn't see any difference switching to an LED setup using the proper wavelength.

A friend on mine from my aquarium club is growing Cryptocoryne emersed using a mix of LED lights specifically made to produce light at about 450nm (blue) and 650nm (red). He switched from normal output T12 shoplights.

He's been running the setup for about 2 years and general observations are; no excess heat generation by the lights, the plants look butt ugly, sort of a browish black colour, under the lights because of the limited light transmission (only 450nm and 650nm) but look normal when removed from under the lights, no noticable difference in plant growth, and a significant savings in his electric bill.

Cheers.
Jim

...technology marches on.

That article about the LED's not being worth it from a payback perspective is significantly out-of-date, and relates only to older, single-wavelength chips. Current technology gets around that by using blue- or UV LEDs to energize a phosphor, which emits white light. The phosphor can be tailored to match pretty much any spectrum one desires.

I would like to know the temature of the led lighting ,I don't mean heat whys i mean color temature and what the intensity from a foot away from the plants and higher. Because if you only have the footage right under the light it would get pretty costly . It seems to me if you grow just compact mini plants these would work for a shelf system. where the plants are only a foot away from the lights . But from what i read the hight they go the intensity of light gets very low .

I have been interested in trying the LED lights from Orchids Limited as well but have been skeptical. But I must say that Orchids Limited is pretty well known and has a good reputation and I don't think they would be using them on their collection if they didn't do the job for them.

Let's take as an example the MR16 Cree 7W-38 degree Natural White bulb. If you want to look at the specs yourself, here is a link:

http://www.orchidweb.com/altpdf/alt_mr16.pdf

The dominant wavelength of the Natural White has a minimum of 3500K, a typical of 4100K, and a maximum of 4500K. Color temperature is directly related to wavelength and if you use the formula to convert to nanometers you get 828, 707, and 644, which nicely covers one of the two main peaks of chlorophyll a.

What I like additionally about the Natural White is that colors of plants and flowers look very natural in color.

If you look at the spec sheet, at 0.5 meters distance, the MR16 7w bulb is producing 6148 lux, which is 571 footcandles. You can use some math to figure out the lux/fc at any distance from the bulb as well as the size of the circle of light created by the 38 degree bulb. That is how I determined that at 30 inches height you get a circle with a diameter of 21 inches with 246 footcandles. If you overlap bulb coverage, the overlap zones have approximately double this intensity. I chose 21 inches because that is the functional width of the humidity trays that I grow everything on.

I think that many experts think that even 250 fc of the right kind of light for 14 hours or so is enough light to grow most Phal, Paph, and Phrags. With the correct bulbs at the correct height and with appropriate overlapping it is easy to have growing zones of 500-750 fc which should be sufficient for many medium and higher light requiring types.

The initial downside to these lights is their initial cost - they are expensive. It is only when you take the longer term view of electricity expense and replacement costs of other lights that you can see yourself breaking even or getting ahead several years out.

Less electricity, less heat, greater bulb height over high-spiking plants, less replacement of bulbs, and a spectrum well suited for photosynthesis were my motivations to switch.

Is induction lighting synonymous with LED?
I have bought a couple of smaller LED lights that I've got shining on my plants along with T5s, which is not going to tell me much. Please keep us posted on how this goes.
Do you mind telling how much your set-up cost?

The BR30 bulbs cost $100 a piece and the MR16 bulbs cost $70. So, it looks like I have spent about $1,900 so far on lights. I eventually need another 6 BR30-type lights but have enough room to grow right now so I can wait a bit. On electricity costs alone it takes many years to get back to even, but if you figure in having to replace fluorescent tubes periodically, the break even point comes much sooner.

Connie - induction has nothing to do with LEDs - it is similar to fluorescent tube lighting except there are certain differences in the way that the gas is excited that reduces heat and improves efficiency.

terryros - the sun is at a colour temperature of 6500K...are you sure you're covering everything?
If you look at PAR (photosynthetically active radiation), there are absorption peaks at 400-500nm as well. I'd like to actually see spectral charts of the orchidweb LEDS.

Btw if you're interested, the cree XP-G LEDs (datasheet here) have emission spectra that are quite decent, also white light (not those horrible blue/red combos), if you ever want to make your own arrays. I know you've invested in these orchidweb lamps already, but if you are hoping to expand, this might be more economical.

The color temperature of a phosphor-type LED varies a bit with the applied current, but many are rated in the 6500°K area, which replicates most-closely the incoming light of a clear summer day, made up of direct sunlight and atmospheric reflection from the blue sky.

You might get a kick out of this: Light Sources & Color Temperature

Thanks for your very interesting comments.
My main doubt is: having this kind of lights a beam angle of 38 degrees, and behaving as spot lights (no diffuse light) how many Led lights would I need to enlight properly an orchid case measuring 1,2 m (height )x 1m (length) x 60 cm (depht), in which Paphios an Phrags are on the ground and the back wall is totally covered by high light requiring mounts?

There really isn't one sun color temperature because it all depends on the time of day, etc. A light that was all 6500K color temperature corresponds to a 446 nm wavelength, which is in the blue part of the light spectrum. Such a light would be bluish. This wavelength covers the first peak in chlorophyll a and b absorption but not the second. There are some experts who talk about this part of the spectrum being important for vegetative growth while the second chlorophyll peak absorption peak in the redder part of the spectrum (color temperature 4400 to 4000k, 640-680 nm) is important for flowering.

Chlorophyll appears to have two types and each type has two separate peaks all in an attempt to be able to photosynthesize under a variety of light conditions, which makes sense as seasons and time of day change for plants. What we need to know is whether both chlorophyll a and b and both of their peaks need to be saturated for optimal growth or whether only supplying optimal saturation in one of the chlorophyll a peaks is sufficient to maximize photosynthesis.

Since the Natural White LED lights I am using do not appear red, we know that although they may have a dominant wavelength in the redder part of the spectrum, they also have some spectrum in the shorter wavelengths.

In any growth situation, you have to consider how much head room above the plants you need, the coverage area required, the footcandles/lux that you need, heat considerations, and electricity cost to figure out what to do. In the box described by monna lisa, I don't think one set of LED lights would work because you are trying to illuminate a base 1.2 m away as well as the vertical wall itself. I think those are two different surfaces. Two different tracks might work (one for the base and one for the wall) but it sounds tricky. The 120 degree dispersal angel LED lights can cover a 1 m diameter circle from a height of about 11 inches, but only with about 210 fc illumination. As you decrease the height, the coverage circle decreases and the light intensity increases. You have to figure out the balance that you need. I have a spreadsheet that I prepared that shows the light intensity and coverage circle diameter for any particular height with the three types of bulbs that I am using.

My understanding of color temperature is that is does not correspond to a single wavelength at all, but is a way to describe the relative ratios of all of the colors in the spectrum.

At lower "electron excitement levels" (temperatures), electrons are are only moderately "bumped" up in energy, so when they fall back, they emit longer, lower-energy light (toward the red end of the spectrum). Excite those electrons more, and they can climb to even higher levels, and when they fall back, they emit higher energy, shorter-wavelength length, moving more and more toward the blue end as the energy input increases. The lower-energy species are still there, so the emitted light becomes a mixture of wavelengths. If they didn't, we'd see a clear, incandescent bulb on a dimmer go from red to blue as the energy increased, not red to white - a mixture of colors.

At about 5800°K, the intensity of the light in the red and blue regions that span the chlorophyll absorption areas are about equal. At 6500°, the blue is slightly greater (the spectra are from a tool that uses the Stefan-Boltzmann Law to predict the spectrum of black-body radiation; the lines are mine, to demonstrate the difference - they are probably not placed exactly correctly):

I would agree that the expressed color temperature of a light is really the dominant wavelength and not the only wavelength. I got my calculations for the translation of color temperature in K to wavelength in nm from this post regarding growing what I think are mushrooms! Below is the link:

Relationship between color temperature, wavelength, and CF light - Mushroom Cultivation - Shroomery Message Board

It looks to me like a specific color temperature does translate to a specific wavelength, but that no light source (?maybe a laser) emits just that wavelength. So, the LED lights I have been talking about cite a "dominant" wavelength range, which means that there are other wavelengths being emitted in lesser amounts.

My reading finds that chlorophyll b is an auxiliary chlorophyll, transferring its energy to chlorophyll a to do the actual photosynthesis. However, the relative importance of chlorophyll absorption in the shorter wavelength, bluer 400-470 nm (7244-6101K) part of the spectrum compared to the redder 625-675 nm (4636-4293K) part of the spectrum I have not been able to figure out. Maybe we don't know for orchids and I will just have to find by getting poor growth with these lights. That is why it is an experiment.

Photosynthesis is much more efficient if you start at photosystem II (I think that is Chlorophyll B, whichever one absorbs at 680nm). Between photosystem II and I (yes, II is first, it kills my students) there is an electron transport chain that will result in the generation of significant amounts of ATP. The 'leftover energy' is passed to Photosystem I (+more photons) which goes through the other chlorophyll which absorbs at 700nm. This kicks the electrons up to the point where you can reduce NADP+ to NADPH.

You need both ATP and NADPH in the calvin cycle (dark reactions) to make sugars. ATP is generated by photosystem I in the absence of photosystem II, but I would bet good money that the best option is to supply both 680 and 700nm for optimal results. Of course other wavelengths are necessary for proper growth and flowering, too.

I'm interested in these new LEDs, I might have to try them soon.

The 680 and 700 nm absorption optimums for photosystem II and I are nicely in the redder part of the spectrum and would appear to be ideally covered by the dominant wavelength of the Natural White bulbs I am experimenting with (644-828 nm).

I think I remember reading that the blue spectrum absorption of chlorophyll (400-480 nm) developed in deeper ocean plants as an adaptive response to low and filtered light situations. Thus, it must do something, but maybe it isn't an essential part of the energy/sugar production cycle of the plant. However, I have heard anecdotally of orchids grown only under bluer light that have been vegetatively spindly and won't bloom but also of some grown only under high pressure sodium lamps (very little blue) that won't bloom. Since the Natural White LED bulbs that I am using are clearly not red, I am assuming they also have light in the shorter wavelengths, so with luck there will be enough bluer light to satisfy those picky orchids as well.

Most non-phosphor type LEDs DO have a "dominant" wavelength (some are very "pure" and do emit in a single one), but we should not confuse that with being the "color" of the light emitted.

I think the mushroom piece is incorrectly interpreting things. If you read the wiki article on Wein's law, it says the predominate wavelength can be predicted, but that does not tell you anything about the appearance of the light. Examples given includes the sun (5778°K) which calculates out to a predominate peak at 502 nm - right in the middle of the visible spectrum - and an incandescent bulb (1500°K) being 2000 nm, which is WAAAY in the infrared. If we took that to represent "the" wavelength that interacted with our plants, we would incorrectly conclude that an incandescent bulb can be of no value, as that 2000 nm does not correspond to any absorption by chlorophyll.

Earlier, it was mentioned that 644, 707, and 828 nm were the "dominant" color emitted by lamps of 3500°, 4100°, and 4500°K. Maybe I am TOTALLY missing something - and I have read the Wikipedia article to which we were referred by the mushroom site - but I still cannot buy the "color temperature relating to a single wavelength" assessment because none of those wavelengths correspond to white light at all - 644 nm is very red, while 707, and 828 nm are both in the infrared.

If you look at the spectra corresponding to those color temps (below), the peaks are, indeed, at the wavelengths the calculation would predict. But you can see that they do represent two IR and one red light, while the color we would see - due to the other wavelengths in the spectrum) are yellowish to bright white represented by the "appearance" dots associated with each.

http://www.firstrays.com/Pictures/temp/3500-4500.jpg

There are a couple of other things to keep in mind:

1) Chlorophyll absorbs in the blue end of the spectrum too, and none of those light sources is particularly strong in the blue end.

2) Shifting to the "hotter" light gives you significantly more intensity of light in both of the chlorophyll absorption regions - including those tree specific wavelengths in the red/IR end.

Leaves me back in the completely experimental mode. I don't think I can gonto the hardware store and buy a cheap spectral analyzer for the bulbs! We know of one grower who has been using the MR 16 7 w bulbs for 4 months and has been getting excellent growth. Only time is going to tell whether I am close or far off with the choice. For now, I have headroom over plants, have eliminated my excess heat problem, and plants and flowers look their natural color under the lights. Many things are blooming, but this all started under fluorescents. I would guess I almost need a year cycle to know what works and doesn't work with the lights. I will then need to post a more detailed report.

Hi All,
I found the scientific paper at this link to be most interesting:

www.hcmiu.edu.vn/BME2010/Papers/P2.19.pdf

Happy Holidays, Ambrose

Hi, I am new to the forum. I really get into indoor trees but I also have some orchids. I have used a ton of different LED grow lights. Attached are a couple of pics from my living room, the experimental area. The "Grow UFO" type lamps are producing intense fruiting in the miniature orange tree even in the dead of Chicago winter. the real benefit is that you can get them right on top of the plant because of the low heat. With orchids I have only been able to make a plant bloom with red light. Just empirical info but my recommendation is to go heavily towards the red end of the spectrum. Keep in mind a lot of the LED products on the market are geared towards cannabis growers where you are trying to produce more vegetative growth at different times.http://184.72.239.143/mu/43a73520-8467-62fd.jpghttp://184.72.239.143/mu/43a73520-847a-dbd6.jpghttp://184.72.239.143/mu/43a73520-848b-4e78.jpghttp://184.72.239.143/mu/43a73520-84ad-8ada.jpg

Nice lghts. They look to be about 650nm? It prolly wouldn't hurt to add some blue in the 450nm range to catch both peaks for photosynthesis.

Cheers.
Jim