LED lights

[ehanes7612]

Talking to Terry Rosborough about LED's (he had an article in Nov 2011 Orchids)..I am now convinced to using MR16's to grow paph seedlings ..curious if anyone has had any experience with this...i guess i need bulbs in the 4000 to 5000 K range

 

[Justin]

http://www.slippertalk.com/forum/showthread.php?t=23962

 

[Lanmark]

I use BR-30s and PAR-38s. I use a combination of 4000K, 5000K and 3000K lamps. LED white light lamps, regardless of the kelvin color, generally cover the full spectrum aside from UV and far-infrared. The spectral gradient curve is very smooth unlike the sharp peaks and valleys found with fluorescent and other types of lighting. The differences between the different kelvin colors of individual LED white light lamps are in the proportional sizes of the peaks within the spectral curves.

What I have found to be the most important factor is the intensity of the light beam being emitted by the lamp as expressed in degree of beam angle. The more narrow the beam, the more intense the light will be which reaches the leaf surfaces but with a smaller area of coverage per lamp. The wider the beam angle becomes, the greater the area of coverage becomes but the light will be much more diffuse and less intense. LED white light lamps are working beautifully for me. I couldn't be any more pleased with the results.

The reason I use LED white light lamps rather than the LED grow lamps which have the blue and red lights is because those red/blue grow lamps emit an unpleasant reddish purply color which gives me a headache in no time. I find it very difficult to enjoy the natural colors of my plants and flowers under such type of colored lighting.

Another factor to consider is the CRI rating for your white light LED lamps. Early white light LED lamps had very low CRI (color rendering index) numbers, especially for those which were in the 4000K to 6700K color range, but recent advances in technology have brought to market many white light LED lamps in that higher kelvin range of 4000k - 6700k with CRI index numbers of 80 to 85 and greater. This is a significant improvement over those old CRI numbers of 65 for a 4000K lamp!

 

[TyroneGenade]

For more LED data see http://www.apsa.co.za/board/index.php?topic=4454.0 . Cool whites supply the most photosyntherically useful (PUR) radiation followed by neutral whites.

 

[Lanmark]

Cool whites supply the most photosyntherically useful (PUR) radiation followed by neutral whites.

...as shown in the chart I posted, but I should have explained it better. :wink: I don't use exclusively the cool and neutral whites, however, because I prefer a more natural appearance to the lighting in my indoor gardens. Having a few of the warmer colors mixed in makes things seem much more natural to my eye. It's a personal aesthetic preference, yet my plants still flourish because they get plenty of the light they need. The tricky part, as with any plant lighting system, is to provide adequate light levels for the plants being grown without providing too much. LED technology is rapidly improving. Lumens per watt and CRI numbers have all increased dramatically over the past year or two. The future looks bright!

Those of you who wish to use the blue/red LED grow lamps will find continued advancements in technology along those lines as well. A lot of people are getting great results! :clap:

I am now convinced to using MR16's to grow paph seedlings ..curious if anyone has had any experience with this...i guess i need bulbs in the 4000 to 5000 K range

The only difference between my own experience and that which you are considering is the size/type of lamp. I believe you will have success with the LED MR-16s as long as you provide the correct intensity of light for the plants you will be growing. Lamp configurations abound -- there's one for every conceivable application. Pick and choose wisely and you will find success. I see no reason why MR-16s wouldn't work well for Paph seedlings. :wink:

 

[terryros]

I agree with everything Lanmark has said. As stated in my AOS article, I am using the "natural white" spectrum LED lights because I need things to look "natural" colors and give good growth. My MR16 bulbs are Cree chips while my BR30 bulbs are BridgeLux. I think you do need a good light meter (which can be had for under $70) to carefully insure that your plants are receiving enough illumination. It is easy to tell whether the circle/area of light coverage is correct with the height you have chosen. My past 14 months experience is telling me that I need between 300-500 footcandles illumination in the leaf area and I have elected to use 17 hour day lengths for most of the year to get good photon flux. I think you can get acceptable growth with less than this photon flux but I am trying to find the optimal illumination with my growing areas and lights.

 

[ehanes7612]

basically i want to start out growing as supplemental light in the GH and eventually growing smaller seedlings inside the house (where i dont have to worry about warmth)...talked to some hydroponics stores around seattle and they dont want anything to do with LED's ...lots of reason...they are entrenched in the flourescents and HID's ..they have no incentive right now to stock them ...will be hitting up Orchids limited
soon

 

[Lanmark]

The Aeon (ALT) Natural White LED lamps are very good! I have some of these. I believe these are the brand of MR-16s which Orchids Limited sells.

I'm interested in reading Terry's AOS article now. I haven't seen it yet.

 

[ehanes7612]

The Aeon (ALT) Natural White LED lamps are very good! I have some of these. I believe these are the brand of MR-16s which Orchids Limited sells.

I'm interested in reading Terry's AOS article now. I haven't seen it yet.

good article ..convinced me but then again i only knew about the really expensive panels

 

[Lanmark]

I've had success with various Neofinetia falcata cultivars under the LED lamps -- Laeliocattleyas, Phals, other mini vandaceous species and hybrids too.

 

[Leo Schordje]

My experience some 4+ years ago with the red and blue lamps was a bad experience. The crap assembled in China, and sold for what seemed to be top dollar, all failed within 3 weeks. The vendor really tried to make good, successively sent out replacement lamps, but the replacements failed within 3 weeks also. After the 3rd replacement, the vendor was frustrated and I gave up. I won't try them again until I can find lamps assembled in the USA or Germany, with parts made in the USA or Germany. :viking: Buyers beware. Prototypes are often made and tested in the US, perform well and get good write ups, then the manufacturers off shore the production and the quality control from China is non-existant. LED is still too expensive to put up with low quality. This is one technology I won't revisit for at least another decade. I also think this is the issue that causes so many hydroponics shops to avoid LED, they can't afford selling problems to their customers. That's my experience.

Honestly, I think in principle LED is a great technology, but as of 4 years ago, it wasn't ready for prime time, and it is too expensive for me to risk trying it again, especially since the $12 shop light fixture with the $1.99 cool white T-12 lamps is really good enough for most Paph seedlings and all manner of shade loving orchids, as long as they are small enough to keep within 12 inches of the T-12 lamps. I have a couple cool white shop light benches set up where the fixture has been trouble free for 20+ years. Just have to replace the lamps every 2 years. I do use T5's and HPS lamps in other areas for my taller & high light plants, but I'm just pointing out that there are tried and proven quite adequate older technologies that don't have the problems that LED's seem to have.

I do encourage the collective "you guys" to work the bugs out of using LED's so when I check back in 5 years from now all I'll have to do is read a short one page post and have all I need to know to set myself up. :evil: But I can't afford the cost and frustration to go with LED's at this time.

My 2 cents. viking: can you tell I'm still mad about the money lost 4 years ago?)

 

[littlefrog]

I took the plunge earlier this year, and I have yet to get a bad one... Liked them so much I'm selling them now. Cheaper for orchid people. If you are growing a profitable 'crop', you pay full price. Lord knows orchids aren't profitable.

For supplemental lighting in a greenhouse, why would you want white LEDs? The blue/red ones are much more efficient (you don't make wavelengths the plants don't use) and frankly the technology is better established. It is good enough for all around growth, and if by chance there is something missing you have some natural light you are covered. I've been growing without any natural light, seems great so far. There are some good companies out there. I work with Sunshine Systems, but I've seen some other brands in action and they are mostly good. I won't recommend a particular unit, since I don't know quite what your application is, but you can see some in action on my website.

I have had good luck with a new supplier of white LED units (I sell those to terrarium people). They seem pretty solid. A mix of 6.5k and 4.5k chips. Definitely bright enough you don't want to look at them... I can even get them with a couple blue and red chips. You really need to do your homework on the white ones. I'm sure the units that Orchids Limited sells are good, too.

Rob

 

[goods]

Rob, would you say the Jungle Dawn (white LED) lights are bright enough for growing orchids?

 

[littlefrog]

I suspect the 13W LEDs will be enough to bloom anything. The trick of course is to put the plant at the right distance. That is the part I'm not sure of, and it is going to vary by orchid. I haven't had them long enough to thoroughly test them. There is very good feedback from people in the vivarium (frog) hobby who have used them longer than I have, which is quite promising.

They are at least as bright as a 26+ watt compact fluorescent (which is about the same as 100W incandescent), and the spectrum should be adequate. People are using them to get good growth on the bottoms of 18-24" tall terrariums. The LEDs run much cooler than CFLs, although they still produce some heat of course. This is why they are good for terrariums, hot bulbs can cook valuable plants (and valuable animals, like dart frogs!).

 

[goods]

I've got too many of both of those (plants and frogs)...

I have seen the results growing non-orchids under these, but I haven't really seen anyone use them for orchids. I have a fridge that I've converted into a terrarium for cool growing orchids, but I haven't figured out a good way to light it yet. I'll start a thread tomorrow with pictures, but these LEDs are one of the options I'm looking into.

 

[ehanes7612]

I've got too many of both of those (plants and frogs)...

I have seen the results growing non-orchids under these, but I haven't really seen anyone use them for orchids. I have a fridge that I've converted into a terrarium for cool growing orchids, but I haven't figured out a good way to light it yet. I'll start a thread tomorrow with pictures, but these LEDs are one of the options I'm looking into.

read the article in Orchids magazine nov 2011

 

[Hera]

Ive been switching over as my T5 bulbs need replaced and ive had good growth under them. So far there is spiking in the phals but my catts are still seedlings so i won't know on that front for awhile. Im hoping they last longer than my T5 bulbs which seem to burn out way to quickly.

 

[littlefrog]

I've got too many of both of those (plants and frogs)...

I have seen the results growing non-orchids under these, but I haven't really seen anyone use them for orchids. I have a fridge that I've converted into a terrarium for cool growing orchids, but I haven't figured out a good way to light it yet. I'll start a thread tomorrow with pictures, but these LEDs are one of the options I'm looking into.

Probably heresy, but orchids aren't any different than other plants, really... Especially other epiphytes.

I had good luck with masdevallia and restrepia under the blue and red LEDs. Until the aphids showed up. Aphids are invisible under those lights.

 

[Ray]

For those of you who are serious about LED light, check out the sevengens.com website, put together by Don Ellingham, an engineer with Phillips. Most of the folks involved in the discussion are looking at food crops, but we have a smattering of ornamentals stuff in there.

Of particular interest to me is the page outlining plant responses to specific wavelengths, which supports my opinion that "just" red and blue LEDs might be "sufficient", but probably isn't optimal.

 

[goods]

ehanes, do you have a copy of that article? I don't have access to the AOS magazines at the moment.

Rob, I mentioned non-orchids because I'd seen low light and foliage plants doing well under them. I didn't know if they provided enough light to bloom orchids. I've seen your video with the red/ blue LEDs, but I keep the terrarium in my room. White light is much easier to look at in my opinion, so I was wondering if two of the Jungle Dawns in something like an Exoterra hood would be sufficient.