they aren't up to par yet, nor are they cheap. i would wait on these lights and stick to HID lighting or CFL for now cuz they are extremely expensive at the moment ($600). i have a buddy who has had some success with them (He makes them) but they aren't practical at the moment becuz similar to CFL growing you need multiple points of light from all sides and at $600 a pop it would be cheaper to buy 1 HID light for $200 and get 10X the results.

Yes, I grow orchids and carnivorous plants with red & blue LED plant grow lights. I have also chosen to be a distributor of a certain brand of LED plant grow lights.

I think that more people will give LED lights a try as the technology becomes more widely available.

Yeah, thanks for telling me about these LEDs Jeff! Real nice ;)

I just found out about this by accident. Do they work? I've got six racks of two 4' fluorescent tubes each going. If these LEDs work it's going to save a lot.

What's the deal you need all the colours or just reds and blue? Some of the photos look like there are oranges and yellows in there too.

Will the bigger LED House Christmas lights work? Or are these special LEDs? You gotta know the price will drop like a stone once a mass manufacturer gets on it.

Do they sell this kind over here?

Here is a link that might be useful: red and blue LED lights

Do they work? Of course they work. They give off light. The real question is how many of them you need to give enough light for your plants. The Growmaster marketing material suggests that 3W per square foot is adequate but don't say for which plants or approximately how much fluorescent light this would be equivalent to. I don't believe for an instant that this level would replace my 20W per square foot fluorescent lighting, but lets assume for a moment that it would. I could now replace four fluorescent tubes with four grow bars, total cost $800 and saving me something in the range of $5-$10/month. Add in an extra $10/year for replacement of tubes and possibly a ballast over the longer lifetime of the LED system, although I'm guessing LED technology will have moved so much in just 2-3 years that you would want to replace the whole thing.

What's the deal you need all the colours or just reds and blue? Great question! One of the major "selling points" of LEDs is that they are able to provide the same plant growth from less light (hence less power) by targetting exactly the spectrum that is most effective for plants. In its most simple terms this means a particular red wavelength for photosynthesis, mixed with a small amount of blue for controlling plant size, shape, and growth. The Growmaster lamps include further wavelengths for purposes which are proprietary and not explained. Some mention is made of extra blues and deeper reds, as well as some invisible (UV?) light, contributing to compact growth and promoting blooming.

Will the bigger LED House Christmas lights work? Again, yes they will work. But again, the question is how effective they will be. The answer for the Christmas lights is "not very"! These lights are cheap and designed to look good to our eyes, they are not in any way optimised for plants and will certainly be less effective than your fluorescents.

There was an earlier post that if you provide enough of each necessary wavelength that you will succeed. I agree after researching this same topic.

The "NASA" mix of 60 blue and 165 red LEDs (225) total is for the monoculture studies they were conducting. Reviewing the short section of Rebecca Northern's Home Orchid Growing brought my answer into focus: Growers have been trying to optimize light sources since windows have been invented.

The short and simple answer is that plants need enough of the right photons with energy to power the chlorophylls for sugar production. The power generated has to exceed the power expending in growth and maintenance activities so day and night time temperature become relevant.

The light mixture and amounts differ among plants because light sources at the earth differ by altitude (bluer at high altitudes and redder at lower altitudes) and the position of the plants in the forest canopy (higher intensities higher up in the canopy and lower intensity on the forest floor).

Orchids are in particular aren't on the top of the plant food chain - they succeed as opportunists hence the variety of species with specific niches and gimmicks to manipulate pollenation and seed spread. With respect to light, one will probably find different ratios of chlorophyll a and b among the different orchid varieties. Botanists find this true among the variety of plants that have different cell wall thicknesses to exploit higher or lower light intensities ( photosynthetic photon flux density), i.e. the overhead light flickers on leaves.

Also the reflected and filtered light through forest canopies changes the light spectra falling on leaf light receptors. It becomes greener and yellower. Plus light spectra change with time of day and season. Plant growth cycles change the mix of reflected and reflected light.

For growers using artificial light, light intensities drop off with the relation of 1/r**2. This is why high intensity lamps on the 20 ft high ceilings of factories can be rationalized in place of fluorescent lamps over the work tables. There is a higher operating cost that is offset by light availability over a wider area plus the less tangible issues of convenience and work efficiency. For large and tall plants, the fall off of LED intensities require additional light at the sides if leaf surfaces aren't lighted by top lighting.

I think the best articles on light to date come from marijuana growers. Light intensity and lumenosity changes with the plant growth cycles. Seedlings would intuitively have thinnner cell walls and only need low light intensity. As plants mature and cell walls change to support a larger plant, light intensity requirements change. The amount of plant mass increases so the amount of light must meet this demand. At flowering time the plant growth slows down. For some orchid varieties, this would coincide with shorter light exposures per day / night cycles. Light frequencies might also change, e.g. red vs. blue

I considered high intensity LEDs but currently is a tradeoff between brightness and junction temperature. Higher power generates more heat that must be removed to receive full benefit. As the LED junction temperature increases, light output falls. High temperatures and over driving electric current through LED shortens operating life from the 100,000 hour life commonly cited by LED manufacturers. Some Phillips Luxeon LEDs are dropping in price but the output light frequency might not be the best match with chlorophyll energy absorption frequencies. One do-it-yourself LED kit vendors announced a Cree LED kit. Maybe this match may be better.

For now, I am going to try the high brightness 5 mm blue LED panels and try minimizing the LED-to-leaf distance without overly distorting the plant growth. Beside, from my thermodynamic lessons, the most efficient overall process energies are the ones that occur closest to ambient temperatures. That is why fluorescent tubes are less expensive to operate than incandescent bulbs if you can get enough light from them for your particular plants.