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LED Based Lighting

Posted by Grnthb (My Page) on
Sun, Dec 5, 04 at 12:18

Hi Everyone,

I am new to this forum and was wondering if anyone has any feedback about his or her experiences using LED based plant lighting.

About a year ago, I ran into a new product announcement called the "SolarOasis Ruby": www.solaroasis.com, in The Growing Edge magazine.

Since I was not able to find much information about this product I just purchased it. My experiences so far have been very successful with miniature roses, with blooms opening several times a year and lasting for months. The blooms are tight, full, and being grown indoors are free from bug and wind damage.

I love to hear any feedback that you have had using this or similar products.

Therese


Follow-Up Postings:

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RE: LED Based Lighting

leds have potential and it is in the process of being proven by myself and others that are working on the same idea, But, there is a price concern at the moment which makes building led grids on a large scale not cost effective.

we have found that blue spectrum range of 420 nm and red at about 680nm is in the highest range of use during photosynthosis. and inbetween those ragnes you will find some use, but basicly that is the highest of the ranges.

hence why people use 5000k fluros for vegging, blues more for vegging and reds more for flowering ( mh ) and ( HPS )

Leds alos have a certain MCD rating, with is thier light output, once a led is powered with more then it is rated for, it burns out, BUt if you use a over power driver circuit, which means pulsing the power source, we have found that you can in fact double and triple the light output of a led without burning it out.

but, with every action there is a reaction, by over driving an led, you change the NM rating of the led, which is easily enough accounted for by using other ranges that will produce the end result range you are looking for.

Life is another issue, led companies will claim a 10000 hour life of leds, but what they do not tell you is that 10,000 hour rating is from the very first light up till the very last bit of light that comes out of the led, there are certain points of efficeny, and with over driving them you also increase the death rate of leds.

This is a topic that many find interesting an others find not possible, you will see a very fine line, people either say yes you can or no you cant.

Be CAREFUL of led sales, most do not use over drive technologiy which is a copyright, and if they are only taking leds in series and converting to dc, the wave length ( distance of usable light from led to plant ) is next to none.,

There are alot of fly by night compaines out there trying to sell leds, and other compaines charging $1000's of dollars.

For example, that link you gave us, the one phot of the led array that is a 110 ac application, there are 50 leds in that bulb,

take 110 av and divide that by 50 = that gives you 2.2

2.2 volts dc is the average target voltage for an led.

so now you series 50 leds, negitive to positive, one end you will have a positive, one end you will have a negitive in order to have those 50 leds light to their full potential, you need to get each led to 2.2 volts, and with 50 leds, you need 110 volts dc., But you are pluging them into ac , so how do they do that wihtout a power supply?

Diodes. 4 diodes control the alternating current to allow only a true positive lead and a true negitive led, so you turned AC into DC but because of the 60 hz cycle of ac, you can have dips, ( need to understand ac and dc on a scope for this ) but to accomidate that they use a capacitor as a buffer.

This isn't HIGH technology , all they are SELLING you on is the NM ( light spectrum )


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RE: LED Based Lighting

( continued )

So what you aren't being told is how the wavelength from the leds to the plant ( disatnce ) is so disturbed.

There is nothing wrong with companies trying to hype a product, leds found a home and thier going to continue.

but look at it this way, the led lights you shown us, is no different then those plant incadesent bulbs they sell at walmart.

THey claim a great plant light specturm.But those that know, know they are junk. Incadesent bulbs are not effeicent and thier clami to fame is by using the same filiment as any other incadesnet bulb but dyin gthe lense with a color coat to alter the arc ( filiment ) light.

It's all in the ( as seen on TV ) game.


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RE: LED Based Lighting

it sounds like you have done your research. It seems as though it does work. NASA has used or is using a large led array in their research in space. because of its low power consumption & lon life.I did read that article and have been looking fo informationever since. I have experimented w/leds out of cars. they are small arrays of 5-10 leds one is red the other is white in color-spectrum. not enough to try as grow light. also I have an hid headlight that i have plans to try as grow light.anybody exeriment or know anything about alternative grow light tech.....low wattage hid,fiberoptic, led or even microwave-sulfur bulb based tech?


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RE: LED Based Lighting

LEDs are semiconductors. They use the same elements as transistors.

LEDs are rated by current, not voltage. It does not matter what the voltage, as long as the current flow is proper.

Currently, the most efficient LEDs are the monochromatic ones (single wavelength/color). Unfortunately, the available LEDs are still MUCH less efficient than the worst fluorescent lamps.

The white LEDs use a phosphor coating to achieve a spread spectrum (more than a single color). These are even less efficient than the monochromatic LEDs.

The 4-diode configuration, which you mentioned is used to convert AC to DC, is called a "full-bridge rectifier". The output has a severe "ripple" in the shape, which is lessened/smoothed by the addition of a capacitor. That output is closer to 170 volts, not the 110 volt figure. 110 volts is the RMS (root-mean-squared) value of the AC.

Zink


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RE: LED Based Lighting

I'm not even going to get started on this.,

I have spent 3 years on this and fought through harder battles then your post. plain , simple, you do the research this time, if leds are not overdriven, they are pointless. your turn to do the math.

I have done it already.

so your going to tell me that an led with 1.1 volts dc at 20 ma is going to have greater odds then a led at its speced rating of whatever at its speced ma of whatever?

Hmm, ok. three years down the tube to you. silly me

and my method is off? sure, thats why I did it, thats why I metered it,. thats why christmas lights use 100 1.1 volt lights right?

we'll see,


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RE: LED Based Lighting

And oh forgive me great one for not adding to my first post about the required resistance to limit current to that ( mock ) setup,

Theres one in every bunch,


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RE: LED Based Lighting

  • Posted by GaWd z9/10 NorCal (My Page) on
    Tue, Dec 7, 04 at 18:06

That's one way to get your argument heard I guess...


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RE: LED Based Lighting

Thanks everyone for your feedback.

I don't really know anything about electronics so I cannot offer anything in that regard.

I do know that the light has worked well for almost a year now and safe around my kids and kitties because it does not get hot, warm at best.

Any other experiences would be great to hear.

Anyhow, again thank you for your feedback.


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RE: LED Based Lighting

Some seeds germinate better under red light. I use red LEDs in a half sized freezer set at about 50 deg F to germinate rose seeds, see: http://home.neo.rr.com/kuska/led.htm

LEDs do not give off much heat so they are ideal for use in a closed system like the freezer. Also, apparently not much red light is required to stimulate the germination. I put the LEDs in series so that they are operating at their suggested voltage. The number of units to put in series will depend on the output voltage of whatever 110 AC to DC power transformers you have in your "junk" electronics bin.

I have gotten as good a germination rate with this method as any other method I have tried.

Here is a link that might be useful: link for above


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RE: LED Based Lighting

  • Posted by zink 6a (My Page) on
    Tue, Jan 25, 05 at 16:16

There is no argument against LED's, except their efficiency. Physicists say they have the potential to eventually outperform fluorescents and HID's.


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RE: LED Based Lighting

Ping- the leds i'm using are working great. I think eventually is now. I've got some extra 1000 red led arrays for experiments. I'm not sure the nm, but I think about 635-650 about, and they plug right on in, I'm pretty much done using them since I've seen what my new ones appppear to be doing.
Have leds become more efficient than hids and fluors?


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RE: LED Based Lighting

In the last year, I've read some of the sci.engr.newsgroup discussions on the current state of LED technology. These posters are some of the lighting industry's design engineers, researchers and hobbyists. Apparently, monochromatic LED's - those emitting a single wavelength - have approached the efficiency of fluorescents.

So far, the best they can achieve with WHITE LEDs is only half the efficiency of single color ones. This is because the physics and simplicity of the energy conversion results in only a single wavelength being emitted. To produce more colors requires a complexity that really ruins the efficiency.

However, that might be a moot point when it comes to making a plant light. We only really need to be dosing the plant with a couple of specific wavelengths anyhow - as far as I know.

Zink


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RE: LED Based Lighting

Hi all, I've been over on the orchid forum for the last couple of years, but lurking here for a few months. I'm an analytical chemist who works in electrochromic displays and spectroscopy. Anyway, the reason I'm chiming in here is that I think the efficiency of red led's is equal or better than fluorescents. The higher in energy the lower the quantum efficiency and the lower the output. Blue led's have 20% the efficiency of the reds. I think from the photoaction spectra we could get away with some red led's for ~650 nm and maybe some cool white fluorescents or 5500 K MH for the blue. Not blue leds which are very inefficient.

Anyhow I do have a question. How do neon lamps stack up in efficiency in the 650 nm range compared to HP sodium? Also are there any fluorescents based on Helium Cadmium? They should give some nice blue light.

Vince


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RE: LED Based Lighting

  • Posted by zink 6a (My Page) on
    Thu, Jan 27, 05 at 22:20

Vince,

I've only got a second here, but in August, Osram came out with a red LED, at 618nm that has a 2-lm output @ 10mA, or 108 lm/watt. That is a record in efficiency.

As you probably know, the energy required increases as the wavelength shortens, and monochromatic LEDs are a lot more efficient than white LEDs.

Zink


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RE: LED Based Lighting

Why is brightness so important? Is color precision important? What do plants do to protect themselves in full sunlight? The link bellow is tons of science, and great animations of how stimuli effect plant metabolism. ComeOn--Enjoy!!!

Here is a link that might be useful: Plant Metabolism


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RE: LED Based Lighting

I have reports of success at growing cactus under LEDs. A mix of blue and red LEDs picked to match the photosynthetic peaks. Total light output is less than the previous setup, but growth is better. The assumption is that the spectral distribution is better.


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RE: LED Based Lighting

ping! these plants are prolific, just got a brand new african violet flower, and rearanged my gardening shelf to get better light distribution with low to medium light plants on the bottom shelf, and the ones on top one foot from the leds, just beatiful results from these leds.


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RE: LED Based Lighting

I recall reading many years ago that some experiments showed that most plants use mostly red light for growth.

Blue light is used for sensing the direction of the sun, which is important.

Green light is useless to plants. Odd, but since chlorophyll is green, the green light reflects right off and the energy is wasted.

I immediately tried starting corn seedlings in a dark room with an ultraviolet lamp. They grew up toward the light, but died of starvation.

No shock I guess. It does make me wonder if plants could live on Near InfraRed. Light we can't even see, but can feel when you stand in front of a woodstove.

So, the ideal LED array for plants would be red LED's and some blue.

And yes, I recall from electronics classes that LED's can run at varying voltages, but get the polarity wrong and they become DED.

Dark Emitting Diodes.

:)

Other frequencies are useful for stimulating flowering, etc. The theory is that there are other pigments than chlorophyll, that need specific light frequencies to stimulate hormone release. Another way the plant keeps track of the length of seasons, as in when Fall is approaching.

I'd like to see LED banks for seed starting. But for now I think I'll go with overdriving florescents.

Zink, I saw electronic shoplights at a home improvement store but wasn't sure if they were over-drive friendly.

Have you seen any good ballasts lately? Brand names, please.


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RE: LED Based Lighting

I have been growing with LEDs for several years now. My biggest problem is that I am constantly running out of space because of how well the plants grow. So far I have done tomatoes, peppers, herbs, roses, orchids, and annuals.
The only factor preventing solid state from replacing HIDs is start-up costs. Currently, the return on investment when replacing HIDs is about 4.5 years (that is, how long it takes before the LEDs are cheaper to use than HIDs.) The lifetime of LED units should be 5-10 years, so already they may very well be cheaper to use in the long run than HIDs.

I think when you see the startup costs of LEDs drop another 30-40%, they will take over the market.


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RE: LED Based Lighting

Well since Superbright LEDs are selling for about a dollar a piece and it will take a ton of them to equal the light from a couple of 40 watt floro's, I think I for one will be waiting a while to use them for my plants :)

I have noticed LEDs being used in stoplights but I think they are using 50-100 of them for each light and it is payed for with our road tax money, it will take a while before we can afford to replace our light bulbs with them.

For me cost is the first issue followed closely by the limited amount of light produced by each individual LED.

So how many LED's would one need to provide adequate light for a 2x4 foot shelf? My guess would be several hundred dollars worth?

John


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RE: LED Based Lighting

Well, ur comparison makes sense to me :)

But then I use 2 shop lights at $15 each, 4 - 40w cool whites at .99 each, 1402kw by my calc = $141.60 for 24 hrs x 365 which is what I usually use.

So my comparison is $30 + $4 + $141.60 = $175.60. (So the seller to my wife will have to be how little electricity they use and how cool they are :)

What do each of those lights have in them, 40 leds? And are the leds all red as they appear in the pics?

John


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RE: LED Based Lighting

The basic assumption here is that 48W of LED is equivalent to 1000W of HID as far as the plant is concerned. Where is the basis for assuming that LEDs are 20 times more efficient than a HID lamp?

Commercially available LEDs are still no more efficient than a fluorescent so that's not it. A GRO LUX lamp puts out all the light in the right spectrum, just like an LED system, so that's not the difference. Please tell me where an LED system is 20 times better than anything else?


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RE: LED Based Lighting

In comparing the two lighhing systems you have to take into account a lot of things.

All of our lights up until LEDs have heat as a byproduct of their operation. Any heat that is created in producing the light is wasted energy. LEDs are transistor devices and produce very little heat with their light so their energy waste is much less. LED's are low wattage devices, many of the current LEDs operate at 20 milliamps so their energy usage is very low.

Each LED is less than 3/16 of an inch across but 4-10 of them can produce very bright flashlights with little of no noticable heat. Each LED has a lens to focus it. The one's I've played with are 15, 30, and 45 degrees. Across a 12 foot room with single LEDs a 15 degree is a beam, the 30 degree a spot, and the 45 degree will cast shadows with your hand in front of it. There is no heat to the touch with any of them in operation.

The Glow-Master (GM) lights above each appear to have about 40 LEDs each. GM says 3 of them will light a 1x2 foot space and has pictures on their site to show the effect of using them on plants.

The initial cost of LEDs is currently fairly expensive but because they use very little energy to operate they are extremely inexpensive to use. The approx 960 LEDs in the 24 GM lights in ComeOnNowFolks's example only draw a total of 48 watts. Their expected life is 7 years. At it's best a 40w floro is good for one year!

So once you are past the initial cost of the LEDs you are reaping daily savings in operating costs for the next 7 years with no further maintenance costs. Certainly NOT true for any other comparable lighting system.

We are used to comparing lights by wattage. The nature of LEDs prohibits that. Next we prefer "White" light, plants have other preferences for good growth. Taking that into acocunt may help us to understand why LED's can work for good healthy plant growth.

The bottom line is we need to try them before we blast them :)

John


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RE: LED Based Lighting

If more technical information was available, we could draw some conclusions before investing a significant amount of money to try something.

Provide me some information that indicates that 1000 LEDs is equivalent to a 1000W HID.


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RE: LED Based Lighting

I've done a quick review of some experiments comparing LED-based lighting with more conventional artificial lighting, and also comparing different mixes of monochromatic red and blue LED light. There are actually a huge number of experiments! The results seem to vary a little, and a few experiments performed across several plant species show that spectral responses vary between species. But generally, a mix of 80%-90% red and 10%-20% blue seems to produce optimal vegetative growth over long periods. Comparisons against fluorescent grow lamps show either approximately equivalent results at the same light intensity, or in some cases up to 25% improvements for the LED light. I can't find any evidence in any study for a 20-fold benefit from LEDs for any single growth characteristic or combination of growth characteristics.

One last thought on LED longevity. LED suppliers are fond of quoting 100,000+ hour lifetimes for LED. Technically this is correct since LEDs do not fail completely like other light bulbs. They gradually get fainter and fainter while continuing to use the same power, and would be rather useless for growing plants after 100,000 hours. LED lifetimes are properly represented in terms of lumen maintenance. The best quality commercially available LEDs offer 70% lumen maintenance after 50,000 hours, although this can rapidly degrade with higher temperatures. Metal halide and fluorescent lamps typically offer 70%-80% lumen maintenance over their quoted mean lifetime of 10,000-20,000 hours. Shorter recommended switchout times are to maintain lumens at 90%+ of the initial rating. Comparing apples with apples, LED lamps last no more than 5 times as long as a fluorescent or HID lamp.

I suggest you rework the cost comparisons using more appropriate numbers and you'll find that they are not yet cost-effective. Red LEDs are now available offering about 30 PAR lumens per watt and costing around 50c for a 100mW LED. Blue LEDs cost more than double that for similar efficiency. That efficiency is expected to double at a similar or lower cost over the next year or two. LEDs already exist in laboratories that exceed the efficiency of available fluorescent bulbs.


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RE: LED Based Lighting

Can anyone suggest a source for high intensity red LEDs. I was buying at Radio Shack; but it appears that they are no longer carrying them.


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RE: LED Based Lighting

You could try this. I haven't ordered from them but I know people who have.

Or you could try Luxeon for a slightly different approach. Don't know anyone who has used them but they look interesting.


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RE: LED Based Lighting

Hi folks up until today I thought LED lights were for glow only, wrong.Read this and use the link below that to make up your own mind.

LED Technology Has Obvious Advantages
The original SolarOasis Ruby Grow Light offers many advantages to the indoor plant enthusiast. With its energy savings, lower operating costs, small size, and light weight, SolarOasis Ruby Grow Lights bring a new versatility to plant growing.

Lower Costs - The Ruby Grow Light can save you money!

Less Energy Use Conventional grow lights consume between 100 watts and 1,000 watts of power to operate. Each SolarOasis Ruby Grow Light uses less-than 2 watts of power. This energy savings becomes more and more important as energy costs continue to rise. On average, SolarOasis grow lights use 33-times less energy than comparable metallic vapor lights (based on 3 Ruby Gro-Bars per 400 watt MH light). Three SolarOasis Ruby Gro-Bars, used 16-hours per day, at $0.10 per Kilowatt, will cost about $21 per year to operate. The Environmental Protection Agency (EPA) estimates that every Kilowatt of energy produces 1.5 lbs of carbon dioxide (CO2). The EPA estimates that for every 7,300 lbs of CO2 prevented is equivalent to planting one acre of trees. Based on these EPA estimates, each 400 watt metallic vapor light replaced by SolarOasis Ruby Grow Lights will yield a savings in energy-produced CO2 equivalent to planting nearly acre of trees per year.

Longer Bulb Life Based on data published by the manufacturers of components used in SolarOasis products, the expected SolarOasis bulb life is 20,000 100,000 hours. This is ten to fifty times longer than typical glass grow light bulb life expectations. Replacing glass bulbs every year adds a lot to the expense of a growing system. With the SolarOasis Ruby Grow Light you won't be changing expensive bulbs every year.

No Ballast Fluorescent tubes and metallic vapor lamps all need a ballast to operate, and ballasts eventually burn out and must be replaced. The Ruby Grow Light doesn't need a ballast, eliminating this recurring cost from your growing system.

No Reflector Conventional glass envelope grow lights emit light in all directions. In order to use as much of this light for plant growth as possible, these lights are generally fitted with bulky, unattractive reflectors to direct light back toward the plants. With LEDs the reflectors are build right into the LEDs themselves, so no secondary reflector is needed. Almost all of the light generated by the LEDs in the SolarOasis Ruby Grow Light is directed straight at your plants.

Less Waste Heat Conventional grow lights are very hot, running from several hundred degrees to over fourteen hundred degrees Fahrenheit at the bulb's surface. This excess radiated heat output adds to the cost to cool your home or office. Our grow lights are merely warm to the touch, even after operating for hours, greatly reducing your supplemental cooling costs.

Targeted Light Output: Unlike "broad spectrum" plant grow lights, which produce a lot of light plants can't use efficiently, SolarOasis Ruby Grow Lights only deliver the colors of light used by plants for efficient and healthy growth. By leaving out light plants don't need, we provide still more energy savings over conventional plant grow lights.

Greater Safety - SolarOasis Ruby Grow Lights are safer to use in your home
or office!

Lower Voltage Unlike conventional grow lights, which operate on 120 VAC at the bulb, SolarOasis Ruby Grow Lights run typically on less than twenty volts at the bulb. This fact greatly reduces risk or fire or injury, especially in wet growing environments.

Lower Burn and Fire Risk The high heat generated by a typical metal halide or high pressure sodium lamp is more than enough to ignite nearby combustible objects such as paper or cloth. Their reflectors often get very hot as well and can cause severe burns if they are accidentally touched. Our LED-based grow lights operate at just a few degrees above room temperature. Just slightly warm to the touch while running, SolarOasis Ruby Grow Lights are safer to use around children and pets.

Light Weight SolarOasis Ruby Grow Lights have no bulky reflector or heavy ballast, and weigh only a few ounces. The ballast of a standard metallic vapor lamp, on the other hand, can weigh up to fifty pounds requiring special consideration when fitted to a reflector and hung from a ceiling. SolarOasis grow lights are easy to place around your valuable plants, without the risk of heavy objects falling from your ceiling!

Less Fragile The glass bulbs of other grow lights are very fragile. The Ruby Grow Light has no glass parts, and is much harder to break.

Less Environmental Hazard Metallic vapor and fluorescent lamps all contain mercury, a heavy metal identified by the U.S. Government as hazardous to the environment and our landfills. SolarOasis Ruby Grow Lights contain no mercury.

Friendly To Your Plants and Home...

No "White Light" Glare Other plant grow lights use technologies generally used to light rooms and buildings, which makes them very bright to the human eye. The SolarOasis Ruby Grow Light delivers light that is very bright to plants, but relatively dim to people. Your plants get what they need without the "white light" glare you don't want, making our grow lights welcome in your kitchen and living room, instead of your basement.

Plants Stay Cooler There are two types of plants, those whose chemistry works better in hot weather, like corn, and those who like it cooler, like most plants you'd choose to grow indoors. Most cooler growing plants shut down when it gets too hot to avoid losing more water than they can bring up from their roots. The SolarOasis Ruby Grow Light gives your plants all the light they need, without the heat of conventional grow lights, letting them grow quickly at room temperature.

Cuttings Root More Easily The leaves of plant cuttings are often snipped in half to reduce water loss until new roots are formed. For cuttings of many types of plants, this isn't necessary when using the Ruby Grow Light. Since your cuttings aren't wilting under the heat of the sun or conventional grow lights they can keep their leaves to speed new root growth.

Lower Chance of Heat Induced Root Damage Plant roots don't like to be hot, and potted plants left in direct sun are prone to root damage where sunlight heats the surface of the pot. The same damage can occur in closed rooms with hot, conventional grow lights and inadequate ventilation. The SolarOasis Ruby Grow Light operates at such a low temperature that incidental root damage is unlikely.

Less Watering Using the SolarOasis Ruby Grow Light, your plants will transpire less, letting you extend the time time between watering cycles. If you need to leave your plants unattended for a few days they'll have a better chance of surviving if their grow lights aren't drying them out.

Good News for Terrariums and Other Plants Grown "Under Glass" Plants with high humidity requirements, like African Violets, ferns, and many carnivorous plants, are commonly grown in Terrariums, also called Wardian Cases. Unfortunately, the combination of high humidity with the heat from most light sources, either the sun or conventional grow lights, causes a great deal of condensation on the inner surface of the glass, obscuring your view of the plants inside. By using Ruby Grow Lights to light your Terrariums no heat is added, over 85% of the light from the Ruby Grow Light passes through to your plants, and the glass stays mostly clear of condensation. Some seedlings with very high humidity requirements are grown with glass covers over their pots for a period of time. Getting enough light to these plants is a challenge, but not if you use the Ruby Grow Light. The Ruby Grow Light emits so little heat, it can be placed directly on top of the glass cover if desired.

Enjoy Delicate Blooms Longer Flowers are very delicate, as can be seen from the spotting and edge burning they get outdoors. Richly colored rose petals fade quickly under the summer sun. This is not true when flowering plants bloom indoors under the SolarOasis Ruby Grow Light. Miniature roses have been grown with SolarOasis Ruby Grow Lights with blooms that were picture perfect and unblemished, with some varieties having flowers that lasted for months without change.

Greater Versatility Lets You Be Creative...

Completely Directional Most grow lights can only be mounted one way - suspended from the ceiling and pointing toward the floor. And even if they can be hung different ways, their bulky reflectors make this a lot more difficult than you might like. Small and light weight, the SolarOasis Ruby Grow Light can be positioned any way you like. And because it produces very little heat it can be mounted within the foliage of large plants, ensuring all parts of your plants get the maximum light they need.

Use Only As Many Lights As You Need With more cumbersome grow lights, you often have to bring your plant to wherever you are able to mount the light. Wouldn't it be better to put your plant where you want it...on a table, on a shelf, on a windowsill...and bring the light to the plant? The small size and lightweight of the SolarOasis Ruby Grow Light lets you bring the light to your plants. If your plant has a cascading form, arrange lights to shine on the plant the way it naturally grows. There's no need to light up half of your living room just to try to grow a few prized plants indoors.

Special Lights for Special Purposes The SolarOasis Ruby Grow Light is a general purpose mix of light colors, suitable for all plant growth. This is fine for day-neutral plants, but some plants need more red light to coax them to bloom indoors. That's why we offer the SolarOasis Ruby Bloom Light. The Bloom Light increases the amount of red light reaching your plant, helping it bloom indoors. And the Bloom Light can be used with any other type of grow lighting system to add as much red light as you need when it's time to force those flowers to bloom!
Looks like overclocking is going out.
http://www.solaroasis.com/grow_products.htm


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RE: LED Based Lighting

Thanks for cut and pasting an advertisement full of marketing hype.

If you really think they are that great then go buy some, use them, and then come post pictures and quantitative information on you experience.


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RE: LED Based Lighting

  • Posted by GaWd z9/10 NorCal (My Page) on
    Fri, Mar 18, 05 at 10:36

Yep, love the marketing glurge. I can't honestly see how these are supposed to replace full strength lamps. The LEDs surface area is so tiny.

If I had the extra money laying around, I'd put it to the pepsi challenge...

Sam


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RE: LED Based Lighting

Oooo, harsh! I think it would actually make quite a nice paperweight, even a good talking point for parties :)


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RE: LED Based Lighting

I apologize I didn't mean I fell for anything, I thought the things were only good for glow effect and yet someone is actually selling them for growing, here are some more links one from NASA and a few more, I am not selling LED's or paperweights, warning brain food be careful, I copied and pasted again.Keep in mind the atom is much smaller but you split it the right way and boom.I will try these LED's when friend of mine get's back from China, he went to try and find as much info regarding new LED's being developed to be used for growing and healing but he is more into the healing aspect, if he has any success in a few months maybe we can sell you something, who knows, he is a very determined Chinese man, by the way he showed me the research he has done and as soon as he makes it available to the public I will send you guy's a link if you are at all interested, but keep in mind his reasearch is in healing which he say's is same application plants benefit from.I did find one grow experiment on the web in Italy and as far as I could tell it worked, how good, couldn't be sure the grower even knew how to grow even if he had proper grow lights so his experiment wasn't a total waste it grew the plants similar to what poorly spaced fluorescents or 400 watt or smaller HID would do.Hope you like the brain food.Whoops I let a page of research out see if you can find which one, not the real thing, sorry but close, no technical stuff.

http://www.humboldt.edu/~ccat/renewableenergy/yurtledlights

http://www.usc.edu/CSSF/History/2001/Projects

Here is a link that might be useful: NASA and I think they developed what MYLAR


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RE: LED Based Lighting

Groman, could you lay off the smokes for a few hours and repost your message? Pretty please? I couldn't make out anything useful from it and the links don't seem to be relevant to LED plant lighting.


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RE: LED Based Lighting

Hello shrubs_n_bulbs I gave up the smoking but maybe it is the residual effect I do not mean any harm or wish to create ill feelings to any of you guys.
I am not an expert in calculating light, lumen, watts ect.if any of you can check my findings and make the necessary calculations I would be grateful being in the first part of these post were LED questions and answers so here it is

Hey I think I got the hang of this LED's stuff and I am not sure I should
be sharing it with you after you blatenly refused to buy me a free
trip to China and man I always wanted to go to China, sheck out my
calculations, I hope you can follow in case I erred.Roger
Check this and forward back your corrections in same email in ( ) ok (:

How do you convert lumens to mcd ?
There is not an exact conversion since they are different types of
measurements but here is a rough conversion:
If you divide the number of lumens by 12.57 you can get the equivalent
candelas, candelas times 1000 = mcd(does this mean 1000 candelas = 1
mcd)
If you divide the number of lumens by 12.57 you can get the equivalent
candelas, so 400 watt HPS = 50,000 lumens, divide 50,000 by 12.57 =
6,285 candelas, (candelas times 1000 = mcd and The unit of measure
commonly used to describe LED intensity is the millicandela (mcd),
1000 millicandela equals 1 candela so Sebestian we take this one the
RL5-W10015 White clear =10,000 mcd has a 15 angle which it light is
spread and x=.27;y=.28 is peak wavelength or a nanometer
(one-billionth of a meter) is the measurement unit for peak wavelength
and T-1 3/4 is the size of LED.So one LED with 10,000 mcd's = 10
candelas which will require 628 LED's to produce 50,000 lumens, look
it over and see if I screwed up and it is not an absolute way to
convert lumens to mcd's but I think it is close so If my calculations
are right and each LCD used produced 10,000 mcd's check Spectral Graph
http://www.superbrightleds.com/products/led/W10015_bin2.gif so 100 of
these cost 79.00 and to produce 400 watts 50,000 lumens 1000 cost
690.00 so that many LED's cannot be necessary to grow a 4'x4' sq. ft.
grow area because those light sales guy's said their $34.00 bulb would
cover 1 sq. ft. but a 400 watt HPS will cover 4x4x3 which is 48 sq.
ft. meaning we would need 48 of theirs to cover a 400 watt grow area
which will cost $1,632.00 so maybe the calculation is wrong
Again I am only interested in generating knowledge so I can experiment with LED's without going broke on a dumb venture so that is why I like to do calculations before trying something or buying someone else gadgets that are weak and useless and this site is the only avenue which I might get some decent input unless the guy's who started this subject don't come back, and this was conversation with my friend who left today for China, no smoke the truth, I wish I could post controlled grow I found in Italy but is is against site principals to post such a thing.I found the formula on the web the calculations I did.


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RE: LED Based Lighting

  • Posted by GaWd z9/10 NorCal (My Page) on
    Thu, Mar 24, 05 at 2:10

Ehhh? Whiskey, Tango, Foxtrot?


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RE: LED Based Lighting

No, I followed that :)

Yes, the calculation is flawed. 1 candela is equivalent to 12.57 lumens only if the light source emits equally in all directions. LEDs do not. LEDs emit only in a very narrow angle, so much less total lumens.

A 10,000mcd LED with a 15 degree half-angle spread actually produces around 1 lumen. 50,000 lumens would require 50,000 LEDs! The 10,000mcd LEDs cost about 50c (maybe less wholesale in bulk), so it would cost around $25,000 to buy that many.

When the light sales guys say that their 2W (roughly 20 lumen) LED system will cover a square foot they are stretching the truth somewhat. It will make a square foot area bright enough (20 foot-candles) to read a book but not to grow anything useful.


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RE: LED Based Lighting

Ok I saw an experiment I was led to believe was accurate using 1000 LED's 1 large panel on top hinged in middle and 1 panel on each side and I suppose equally balanced out and the person who translated said experiment was closely similar to a 40 watt fluorescent grow and is it a good guess a 40 watt is 3,500-5,500 lumens so if what these guy's claim is true $500.00 will get you lot's and lot's of fluorescent lamps, and LED's are a waste of time, right.


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RE: LED Based Lighting

Sounds about right. A 40W Gro-Lux fluorescent puts out 1,200 lumens, which is about what I'd expect from a 1,000 LED red/blue mix. If you calculate PAR (number of photons) then those 1,200 lumens would be equivalent to a normal 3,000 lumen fluorescent tube, possibly even slightly better since the red and blue light is good for plants. Of course the 1,000 LEDs would be using over 100W of power.

In a few years time when commercially available LEDs are five times as efficient at half the price then I think everyone will be using them for ... well, almost everything :)


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RE: LED Based Lighting

  • Posted by botski z3 Minnesota (My Page) on
    Thu, Mar 31, 05 at 15:54

Grnthb,

Could you provide a few technical details of the LED's you are using, such as the wavelengths, intensity in mcd, and the total number you are using?

I am at the very beginning of an LED experiment for a small basement greenhouse and would like to see how my numbers pan out with yours. So far I have soldered up about 80 red 660nm and 20 blue 470 nm LEDs and run the system over the seedlings (brocolli, jalepenos, roma tomatoes, and basil) for about 3 days. So far so good, they appear to be responding to the light.


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RE: LED Based Lighting

Botski,

I don't know what the numbers are. I just bought the bars from SolarOasis. In each bar, there are 3 heads with 38 LED's per head. The LED's are all different colors, red, orange, blue and green.

I also just bought the bloom version that seems to have more red then the grow version. I have a fuschia that is now in full bloom after 2 weeks of being under the bar. I have it in a dark corner in my kitchen where I hung the light under my kitchen cabinets.

I am sure that you can write the folks at solaroasis and ask them about the lights. They have always been really responsive.


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RE: LED Based Lighting

See link below for comercial use of RED LED for growing lettuce indoors.

Here is a link that might be useful: RED LED for Green Groceries


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RE: LED Based Lighting

Here's a slightly more detailed link. It contains an astonishing amount of corporate deception, but maybe just enough information to get to the truth.

It appears that they are using roughly 15W of LEDs per square foot. I'm assuming that these are 690nm plus 10% blue photons, which has been shown to be the most efficient combination. This combination provides the same yield of lettuces as the same photon flux from HPS lamps. 15W/sf of HPS lamps is about what you would use to grow lettuce, so I'll assume that this is the photon flux they have achieved with these LEDs. This would correspond to an approximately 60% efficiency saving over legacy cool/warm white fluorescents, which is what they are claiming for the electricity saving, so it all ties together.

The best 690nm LEDs I can find for sale in the US produce roughly a third of the photon flux of HPS, which implies they these people have something three times better. Such LEDs exist in laboratories, so it isn't out of the question that they have access to LEDs that efficient or close to it. I hate to think of the startup cost, but given the high cost of electricity and floor space in Japan, it may still be cost-effective. Hopefully we'll be able to get our hands on this sort of LED technology in a year or two.

Here is a link that might be useful: LED for lettuces


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RE: LED Based Lighting

"I think the point has been missed is that the power output from leds is very focused which improve your cost per watt. thanks "
It's good and bad.
One advantage of fluorescent tube is that it's not focused, therefore fewer leaves are in shadow, making the seedlings more stocky. With a sharply focused beam, a lot is under sharply defined shadow.
dcarch


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RE: LED Based Lighting

I was looking into photomorphogenesis and stimulation of flowering in long-night plants. I contacted a seller on e-bay, looking for 730nm. LED's. The seller was actually connected with an LED factory in China or Hong Kong, and
they did a custom run of 730nm Led's for me, 1000 of them
for $100. US. This is important in the phytochrome red
conversion of Pfr to Pr. At the time that I was looking it
up, the research showed that plants only needed a much shorter
period of darkness if first exposed to a flash of 730nm light.
If I were looking for a specific wavelength, then it is possible to economically order from China or Hong Kong.


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RE: LED Based Lighting

Well, I checked back into the state of the art in LED lighting:

Somebody came up with a replacement 48" tube for a shoplight, but the price is still slightly ludicrous at $139 per tube.

There are some specific color LED's that really pump out lumens now, for an affordable price.

I found a Red LED at :

http://www.shopeio.com/inventory/details.asp?id=874&x=Lumileds LXHL-MD1D

Three watts, 44 lumens, ten bucks. If you only wanted to build a spotlight to focus on one houseplant, you could put together a couple of these to make a grow light.

According to :

http://members.misty.com/don/led.html#o

There are some manufacturers reaching for the sky with their candela and/or lumens per watt ratings.

Most of the inexpensive loose LED's you might see on, say BestHongKong.com, will have tiny 1800 microcandela outputs.

But some of the better LED's can produce a hundred times that!

I think this is the wrong time to invest in LED plant lighting. I suspect there will be a giant breakthrough in the next six months or so and whatever I built would be obsolete instantly.


I had hopes of building an array from loose LED's but the actual level of lumens you can get from your average "bright" LED is kind of anemic.

I think one of the problems is size.

While the small LED's are very effective, if you gang up ten of them under a 1 centimeter lens to get some real output they heat up.

More heat means more current, which means more heat, so you have to have a limiting resistor to hold the current down.

The fact that the lens acts as an insulator to keep the LED's warm just makes the heat problem worse.

I look at it this way: the actual filament in your average incandescent light bulb isn't huge, but the glass bulb around it IS.

Maybe that extra volume is designed to allow the heat to dissipate more efficiently so the filament doesn't melt.

If LED's were made a bit larger with more attention to radiative cooling we might be able to buy an LED bulb that uses 10 watts, but produces as much light as an eighty watt incandescent.


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RE: LED Based Lighting

Well, an update:

I found a distributor on eBay that was selling LED arrays.

I bought one in March for $36 including shipping.

Some Blue, some Red. It's made to look sort of like a standard flood light.

I focused the output of the array on my Red Robin tomato plant, which just barely makes it through the winter on the windowsill.

Well ! The leaves turned dark green, the plant began to thrive, and it flowered.

A month or so later I had my first ripe tomato of the season, in late April no less !

Now the drawbacks.

The purplish light from the array sort of hurts my eyes.

It's supposed to be because the human eye responds best to yellow and green light, but blue light has a lot more energy.

So in the dark, your pupils dilate wide open.

The blue light from the LED's is really bright even though your pupils don't react to it, and they say prolonged exposure to that light could cause problems.

So I set the LED bulb on a timer to switch it off when we're in the kitchen.

And the bad news: The bulb was warranteed for 30 days from the transaction date.

Thirty-One days later something happened and a pie-wedge-shaped section of the LED's went dark, about 1/6th of them.

I deduce that one limiting resistor is used per group of six areas on the bulb, and that the resistor had failed.

So the LED's may be all right, but just not getting current.

I contacted the vendor but of course I was ignored.

In other news, I also purchased a set of four LED panels for my grow rack.

It's been a juggling act, but by combining these panels with two overdriven fluorescents I have a combination of low wattage light and enough heat to counter the chill of the cold basement.

That was a problem, as it turned out. The LED's make no heat, and the basement was too cold to let the seedlings thrive.


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RE: LED Based Lighting

Here's another update:

When I would start lettuce under the overdriven fluorescent tubes, there was a problem in setting them outside.

The transition to full sun would usually cause bleaching of the leaves unless I let the plants harden off gradually.

Well, I set out some of the LED-raised lettuce and tomato plants on Sunday, and no sign of sunscald or any distress at all.

Could it be that the LED's really ARE strong enough to mimic sunlight?

I've done some more reading, and I think the next time I buy another set of LED panels I'm going to go with all-blue panels.

The red is for flowering, not something needed in a seedling rack.

I want to use the combo blue and red panels to build a grow box for a tomato plant in a barrel.

I'm thinking of finding a really prolific type, high acid, lots and lots of tomatoes.

Build a mirrored light box, add a fan, thermostat, LED's and a waterproof heating pad -- tomatoes in January !

Silvery Fir Tree tomato is the first to leap to mind, as it's pretty and only grows three feet tall. Can't recall it being prolific enough though.


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RE: LED Based Lighting

led based lighting will emait the color but fails to produce the wavelength of light and color needed by plants. these companies especially on ebay are conning people into thinking its the next best thing and its not. if someone bought me a LED grow light array id sell it and if i couldnt sell it id use it for target practice in the desert.


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RE: LED Based Lighting

lol still don't know what to get...

Do they offer just pure blue/red CFL? Then just throw 4 RED surrounding a blue.


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RE: LED Based Lighting

LED plant lights aren't meant to be measured in lumens. If you see a lumen measurement mentioned in an LED grow light ad- it should be a red flag. Lumens are for human perception or "White Light" the microEinstein is for plant lighting.


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