new Led lights

[monna lisa]

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.

[terryros]

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.

[ericst11]

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.

[ericst11]

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

[calvin_orchidL]

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.

[terryros]

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.

[DelawareJim]

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

[Ray]

...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.

[ericst11]

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 .

[Becca]

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.