LED Grow Light Forum

I figured I would compile some information (from what I can remember) I found from when I was researching LED lighting. The following is quotes from several websites which I found useful. Figured it would be handy to have all the information in one place for our readers here.

This first quote was one I found on myhydroponicgardening.com

LED Grow Lights
You won't find any hype or controversy here. Just solid information about using LED grow lights and where to buy them. Whether this is your first time ever growing indoors or you are looking to switch from your current HID lights, keep reading and make an informed decision. Check out the new "Who Am I?" section to learn more about this site.

Who Should Use LED Grow Lights?
While the reasons to use LED grow lights are numerous, the applications in which LED grow lights really shine are even more so. Users of LED Grow Lights experience great results both in hobby gardens as well as in commercial settings.

Sustainable Urban Farming & Greenhouses
While rooftop gardening and urban farming plots have been around for years, there is a distinct new trend in food production - sustainable urban farming indoors. It can be as simple as setting up a small plot in your basement to large operations buying up warehouse space on the order of 100,000 or more square feet. The combination of hydroponics and LED grow lights really reduce the carbon foot print of such gardens while providing healthy, sustainable food year round to the local population. LED grow lights can be used as the primary source of lighting in basement & urban warehouse conditions as well as supplemental lighting for greenhouses to extend the growing season. Works on everything - from greens to flowering fruits and vegetables. Read More . . .

Commercial Medical Marijuana Operations
Long considered out of reach for LED grow lights, large scale commercial Medical Marijuana operations are now making the switch from HID. Taking a look at this video will show that quality and yield are paramount while still enabling the grower to benefit from cooler grow room temperatures, reduced electricity consumption, and long-term money savings. Proving that LED grow lights can be used successfully in commercial grows, ProSource Worldwide is the only company that can back up its claims for large-scale production. Read more . . .

Algae Production For Biofuel, Food, & Pharmaceuticals
The battle for a renewable and sustainable energy source has been raging for decades with little progress, until now. Research has shown that algae is capable of producing 10 to 20 times more gallons of biodiesel per acre than any other known source. In addition to supplying fuel on a large scale, algae can be cultivated by small-scale farmers to off-set increasing fuel costs on family farms. As another benefit, the byproduct of rendering oil from algae is a high protein and carbohydrate solid that can be used as animal feed and pharmaceutical supplements or further processed into ethanol.

Crisis Gardening & Off Grid Applications


Courtesy of Rory Finneren, Flickr
With each era that passes there groups of people who are determined to not only survive but thrive in the perilous times in which we live. Having a crisis garden is one easy way to ensure you and your family have enough food to weather tough times. Lets face it, crisis gardens are quickly becoming the Victory Garden of the new millennium. However, depending on your geography, you may not have the luxury of a long growing season or you may wish to keep your crisis garden more private. With LED grow lights, it is now possible to extend your growing season or grow completely indoors if desired.

General Hobby Gardening
Gardening enthusiasts have something to be excited about because LED grow lights enable you to enjoy your hobby year round regardless of weather. From growing fresh herbs and produce for cooking, starting plant seedlings in the spring for transplant, to more exotic pursuits such as growing bulbs, bromeliads, tropical plants, and even orchids, LED grow lights are up to the task. The intensity and coverage area of the best LED grow lights on the market makes it possible to grow any plant from basic lettuce to light-intensive plants such as watermelons, carnivorous plants, and cactus.

LED Grow Lights Are Here To Stay
After several years of research and releasing new, improved models, LED grow lights have established a firm foot hold in the grow light market, proving themselves as much more than a fad gadget. Current iterations of LED grow lights can go head-to-head against their HID counterparts, matching (and in some cases, exceeding) the yields and grow quality.

Choosing The Best LED Grow Lights
When deciding on the right LED grow lights for you, please take some time to look at as much information as you can. What I have found is that those that are most vocal in their grow light's abilities are the ones to stay away from. When you find a company that lets it product stand on its merits and abilities instead of hype about uber-penetration and 400% yield increase, that is the company to go with.

LED Grow Light Review
If you are looking for reviews on LED grow lights, then look no further as I actually have several on this website.

LED Grow Light Review - General Discussion Of 2011 Models
Brand Specific LED Grow Light Reviews - Top brands such as ProSource, 357 Magnum, Hydro Grow LED are now available while testing of Stealth Xtreme, Grow LED Hydro - Spectra, Solaro Sun Clone, and other LED grow lights is underway.
If you are interested in LED grow lights for cannabis, check out The Cannabis Grower's Guide To LED Grow Lights. This multi-part guide is updated frequently with new sections, so be sure to bookmark this page.

Reasons To Use LED Grow Lights
By the time you have made it to this site, you have probably heard a wide range of reasons to pick LED grow lights over HID grow lights - some of it is true, some of it is hype, I am sure. The best thing to do is take both sides of the argument and split the difference. Take some time to research the results from independent testing (especially when comparing the offerings of different LED grow light manufacturers).

If you choose from among the best LED Grow Lights on the market, you can look forward to the following benefits:

Energy Savings - The first thing that you see when looking at LED grow lights is claims of efficiency. While some claims are overstated, you can expect to see a 40% to 75% decrease in electricity costs when you switch from HPS or MH grow lights
Near Zero Heat Signature - There are entire websites dealing with how to mitigate the overwhelming heat generated by HID grow lights. By default, LED grow lights emit very little heat and most come with modest built-in fans to keep the chips cool. No more burned leaves, no more excessive dehydration, and . . .
No Expensive Accessories - Ballasts, reflectors, heat removal systems, fans . . . they all cost money and add up very quickly. On top of that, these items do break down over time and replacement costs cut into your potential profit. LED grow lights eliminate the need for these things.

Exceptional Life-Span - With an average lifespan of 50,000 to 100,000 hours, LED grow lights continue to pay for themselves over time. Compare this to HPS grow lights that need to be replaced as often as every 5000 hours and the choice is obvious.
Near 100% Efficiency - At best, an HID light is only 35% efficient which means nearly 2/3 of the light produced is totally wasted as heat or as light that is not used in photosynthesis. With well-researched LED Grow Lights, you can achieve 90% or better efficiency because the light produced falls within the spectra of Photosynthetically Active Radiation (PAR). This just means plants can use the light created by LED grow lights directly for photosynthesis.
Need More Information On LED Grow Lights?
I strive to provide thorough and accurate information at all times. If you have any question about the information on this site or wish to have a topic covered in a future post, just hit the Contact Us button and let me know what you need. Enjoy your LED grow lights!

This one I found on http://www.led-grow-master.com/teachers.html speaking about the environmental effects of energy useage.

"According to the Department of Energy, 85% of the electricity used in the U.S. Is generated by fossil fuels. Of the largest 1000 fossil fuel-fired power plants in the U.S., 77% are
not subject to air pollution controls under the Clean Air Act's New Source Review requirements. The Department of Energy tells us that the generation of electric power
produces more pollution than any other single industry in the United States. The statistics are similar in other industrialized nations. .An important part of reducing our
dependence on fossil fuels is improving energy efficiency (that is, getting more use out of the electricity we are already creating.) The LED Grow Master lights use 33 times less
energy than comparable metallic vapor lights. According to a study by the EPA, this energy savings is equivalent to planting a 1/2 acre of trees per year. Now is the time to see
how the rest of your home holds up. Discuss your electric bill. Check your billing cycle and challenge your family to conserve energy for the following month. Have a wattage
hunt to determine which appliances etc. are drawing the most electricity. Look for ways to reduce your energy consumption and conserve fossil fuels. At the end of the month,
sit down and discuss the wonder of your accomplishment. You've reduced pollution, helped the environment, and came out with some extra money."

Another one from myhydrogarden, they seems to be really fond of the UFO lights, but still have a point with regards to LED lights.

5 Reasons to Use LED Grow Lights For Indoor Hydroponic Gardening
Special pricing and DEALS here on LED Grow Lights.

Everyone knows that, in order to grow plants indoors, you need grow lights. All grow lights emit light at certain wavelengths throughout the light spectrum. What many people don't know is that more than 75% of normal lighting is useless when it comes to growing plants as it emits light that is outside the spectrum that encourages photosynthesis.

Specialized grow lights such as fluorescent, metal-halide (MH), and high pressure sodium (HPS) lamps are more efficient as the light they emit is more concentrated in the wavelengths suitable for plant growth. But the most efficient of all lights available today are LED grow lights. Because of recent advances in the technology, LED grow lights are gaining market share for indoor hydroponic gardening. Despite the increased cost to start out with, they can be superior to MH and HPS lights because they consume a fraction of the power, no ballast required, emit very little heat, and have a very long lifespan. Consider the following features of an LED grow light that make them a suitable choice for indoor hydroponic gardening.

1. High Efficiency

LEDs are produced to emit certain wavelengths necessary for photosynthesis - blue and red. By controlling what wavelengths are used, you make use of your power more wisely.

2. Low Power Consumption

When compared to the high output of metal halide and high pressure sodium lighting, LED grow lights use only 20% to 30% of the electricity. On top of that, you do not have to purchase (and eventually replace) expensive ballasts.

3. Long Lifespan

The typical LED grow light has a lifespan of 50,000-100,000 hours. Compare that to an HPS lamp at 3,000 - 5,000 hours and you can see where replacement bulb cost can add up.

4. Minimal Heat

You cannot burn yourself on LED lighting. This also means that you will not scorch young or tender plants like MH and HPS lighting can. Reduced heat also means less evaporation and less watering.

5. Stage Specific Use

Blue LED grow lights are used initially to enhance vegetative growth for sturdy plants. Red LED grow lights are then used to boost the flowering and fruiting stages. You can use both Blue and Red LED grow lights at the same time throughout a plant's life. To get the most from your plants, it is also important to incorporate light from the orange spectrum. The only light that I know that does this properly is a UFO grow light called The Illuminator.

More...

The Cannabis Grower’s Guide To LED Grow Lights: Lumens

One of the most commonly used terms when referring to the power of a given grow light is the word lumens. For years, it has been the standard measurement of the growing capability of metal halide and high pressure sodium grow lights. The problem is that this term has been used incorrectly for over 30 years. In this article, we will explore the real meaning and correct use of lumens and further describe what you should be looking for when it comes to choosing LED grow lights that pack the most growing-power for your dollar.

What are Lumens and Lux
Lumens and lux are both measurements popular with grow light manufacturers - both HID and LED - to give potential customer a reference point for the relative brightness of various lights. In some jurisdictions, a lamp's lumen output rating must be on the label as required by law. What we are told (and have been for years) is that the higher the lumen rating of a given light, the better, faster, bigger, etc. your plants will grow.

But there is one MAJOR problem with using Lumens as a reference point for growing plants.

By definition, a lumen is a measurement of how bright (the power) a light is perceived by the human eye. The term lux is very similar to lumen in that it measures the intensity of light, however, it also takes into account the total area covered by a given number of lumens. For now, don't get bogged down by the technical side, just know that lux and lumen both measure the intensity of light to the human eye.

So what's the big deal? A bright light is good, right? The sun does a pretty good job at growing things and it's really bright. Don't we want to mimic the sun?



Well, yes and no . . .

Lumen & Lux Are Irrelevant To Plant Growth
Unless the plants under your grow lights have eyes, lumens & lux make zero difference in how well your plants grow. Plants respond most efficiently to light that is beyond what humans can perceive so it does not necessarily matter how bright your light is. As a matter of fact, 80% or more of the light emitted by either the sun or from HID lights, goes unused by plants for photosynthesis. It is that portion of light that we humans see with our eyes and can register as being bright.

What matters most are the wavelengths of light that your grow light emits. When an LED grow light manufacturer rates their lights based on lumens, it is flat out misleading and irrelevant. Some manufacturers realize that people are starting to learn about this and are now skipping the word "lumen" and just showing pictures of how bright their light is. The result is the same - a bright light does not guarantee big yields.

Choosing An LED Grow Light For The Right Reasons
Making an investment in LED grow lights is nothing to take lightly. There are many factors that, if considered carefully, can almost ensure big yields. But you must take the time to educate yourself and explore the manufacturers claims. You best bet is to be sure the lights you buy come from a manufacturer that offers not only a warranty against defects but a guarantee that, if you don't like the results, you can return the lights for a refund.

Be sure the light you choose covers the correct spectra and offers an appropriate amount of power for your specific grow operation. This article is only part of a multi-part series about growing cannabis with LED grow lights. Come back often for updates and don't hesitate to contact us for help if you need it.

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The Illuminator Grow Light Gets Massive Update From Tri-Band to 5 Band

What is The Illuminator LED Grow Light?
When the Original Illuminator Tri-Band grow light was introduced a few years ago, it was a true innovation in an already progressive industry. By introducing light from multiple red and blue wavelengths, this LED grow light allowed users to enjoy thicker, richer vegetative growth and powerful bloom cycles not seen before with a standard LED grow light.

How is the 5-Band, Tri-Spectrum Illuminator better?
Now they have upped the ante with the introduction of the 5-Band Illuminator Grow Light - visit their site here. Featuring proprietary technology, the 5 Band Illuminator LED grow light emits light in finely tuned wavelengths of blue, red, and near-red.

Proprietary Technology? What does that mean?
It means you cannot find the same growth-inducing, bloom-exploding, and yield-boosting technology in ANY other LED grow light on the market. Don't get me wrong - there are many decent lights out there and even more cheap knock offs but they lack the research and development put into the Illuminator grow light to make it the industry standard.


How does light affect plant growth?
Here is a quick science lesson for you . . . why are leaves green? Very simply put, leaves are green because they absorb almost all other light except green/yellow, which is reflected back to our eyes and is what we see.

Red, blue, and near-red are the 3 wavelengths of light that are the most beneficial for plant growth. Light from the green and yellow portion of the spectrum provides very little to no benefit to the development of your plants because most of it is reflected back.

Therefore, it would make sense that you would not use light from the green and yellow spectrum in a grow light as it would just be wasted. The innovation in design of the Illuminator Grow Light is in the configuration of wavelengths the light employs that emit the most desirable spectra. By utilizing a new technology, the Illuminator effectively duplicates wavelengths of light that your plants just gobble up, resulting in increased yields and massive blooms not normally seen with indoor growing with LED grow lights.

Important Facts About The Illuminator 5-Band Tri-Spectrum Grow Light
Illuminator LED Grow Lights use a 5-Band spectrum of red, blue, and near-red which delivers more than 95% absorbable light to your plants. When compared to 15% efficiency typical with High Intensity Discharge Lighting, the results can be staggering.

Plants need different wavelengths of light at different stages of growth. To that end, the goal in developing the Illiminator Grow Light is to deliver optimum wavelengths required by your plants while giving support to all cycles of plant growth.

Illuminator LED Grow Lights are becoming as mainstream as Metal Halide & High Pressure Sodium

Beam angles.

LED Grow Lights – Understanding Beam Angles

This is a special guest post by Nate from LED Grow Lights Review. He gives out solid info and is funny as well!

One of the things that really confused me when I was first researching LED grow lights was the beam angle. The companies selling the LED grow lights were always saying things like, “120 degree beam angle for maximum coverage.” Or “90 degree beam angle for great intensity.” Or “60 degree beam angle for maximum penetration.” As I read this advertising I sat there dumbfounded. This is what I was envisioning in my head:



Well, it turns out that my first assumptions were incorrect. The LED grow light experts are not talking about the angle from the light fixture when they talk about beam angles. They are talking about the angle of the light that is coming out of each individual light emitting diode. Remember that each LED grow light you purchase is made up of many individual LEDs. These individual LEDs look something like this:


Each diode’s beam angle can be controlled.

One of the great things about LEDs is that you can control the exact angle that light comes out. With traditional HID lights there is no control over these beam angles. This means that traditional HID lights are always shooting out at 360 degrees in all directions (this is a waste of energy). Even if you have a reflector, you are still losing some light from an already inefficient light source.

A Visual Representation of Beam Angles
As you can see in the diagram below, a 120 degree beam angle really spreads the light beams out. A 90 degree beam angle is more concentrated and a 60 degree beam angle is even more focused.


So which Beam Angle is the Best for LED Grow Lights?
That is a great question, and unfortunately the answer is, “it depends.” You see, an LED grow light with 120 degrees casts a wider net. This means that a 120 degree light has a larger coverage area because the light is spreading out everywhere. You can fit more plants under a 120 degree light than you can with a 90 or 60 degree light. However, the 120 degree light is not as concentrated and does not penetrate to the lower levels of the plant very well - a wider beam angle means lower intensity. Most experts agree that this beam angle should only be used on plants that are very short, non-flowering plants like lettuce and herbs, however, even those plants can grow better with more intensity.

On the other hand, the 60 degree light does not cover as much area as the 120 degree light does, but it emits plant-growing light farther and at a higher intensity. That is why you are seeing most of the newer LED grow lights with 60 and 90 degree beam angles, a combination of both, or secondary lenses. This has been a step in the right direction for those growing light-intensive plants like medical marijuana, tomatoes, peppers, etc. In fact, some of the early grows with LED grow lights didn’t turn out as well because the wide beam angles didn’t allow for proper penetration which resulted in poor flowering. With more narrow beam angles, this early problem appears to be a thing of the past.

Conclusion

In summary, beam angles refer to the angle of each of the individual LED chips. It does not refer to the angle of the light fixture itself. You might be okay using a 120 degree LED grow light for shorter, less light-intensive plants, but for most growers, a more narrow beam angle is what you need.

More...

The Cannabis Grower’s Guide To LED Grow Lights: Spectrum & Wavelength

With the increasing popularity LED grow lights, manufacturers and distributors are innovating new ways to capture your attention. They like to lace genuine science with a healthy dose of marketing hype in hopes that you pause just long enough for them to dazzle you with the latest hyperbole. There are so many terms being thrown around, it can be difficult to dissect reality from marketing hype.

One of the common ways they try to get your attention is by talking about the light wavelength and spectrum used by their LED grow lights. Here is a simple run-down of what is important and what isn't to help your LED grow be all it can be.



LED Grow Light Spectrum
When discussing light, spectrum simply refers to a range of wavelengths of visible light in the entire electromagnetic spectrum. Aside from visible light, the electromagnetic spectrum includes energy (radiation) from radio & microwaves, infrared, ultraviolet, x-rays, and gamma rays. Incidentally, the plural for spectrum is spectra not the often-seen spectrums.

In any case, grow lights are concerned primarily with the visible spectrum though, occasionally, utilize both infrared and ultra violet spectra as well.

LED Grow Light Wavelength

In terms of an LED grow light (or any lights for that matter), the term wavelength refers to the distance between peaks and troughs in a wave. Light wavelengths behave similarly to waves in water and their peaks can be close together or far apart. It is this trait that determines the color you see from red (long wavelength) to blue (short wavelength). Each shade of light along the visible spectrum can be measured in nanometers (nm) that range from 380nm to about 780nm, from blue/violet to red, respectively.

It is from within the visible light spectrum that plants derive all of the energy needed to conduct photosynthesis and grow. Taking advantage of how plants react to certain wavelengths of light is the basis behind the the development of LED grow lights.

How LED Grow Lights Promote Plant Growth
Even though HID lights have leanings toward a particular end of the light spectrum (blues for metal halide, yellow/red for high pressure sodium), they emit light in the full visible spectrum just the same way an everyday light bulb does. In general, plants respond in some fashion to all light, however, they get the most benefit from various blue and red wavelengths. Consequently, they get the least benefit from greens and yellows as most of it is reflected back.

Initially, LED manufacturers thought all that was needed was a single band of blue and a single band of red light - given at the right stage of growth - and you would have success. While this may have worked in limited testing on simple plants such as grass, it failed (or produced undesirable results) in more complex plants such as tomatoes and, of course, cannabis. This did not stop many manufacturers from blasting out poorly designed models in the early days of LED grow lights which is why this industry is still trying to separate itself from this bad reputation.

Necessary Spectra And Wavelengths For LED Grow Lights

Early adopters of this technology saw plenty of promise and, fortunate for us, kept pushing the technology further. What they found was that initial models were at least partly right - they had the concept of red/blue light down but it lacked in delivery. It was discovered that more wavelengths were needed in order to address the short comings of the first models. When looking at a PAR chart, you can see that there are distinct peaks along the visible light spectrum at which plants derive nearly all of their energy required for photosynthesis. Further testing showed that there are two distinct peaks in each of the blue and red spectra and a single, smaller peak in the orange spectrum. What this means is that 3 light spectra are needed in a total of 5 light bands (wavelengths).

What we have now are LED grow lights that are optimized for full-cycle plant growth; from vegetative growth to flowering. Keeping things simple, light from the blue end of the spectrum is necessary for vegetative growth - making for strong, healthy plants with thick foliage. In contrast, red and orange light are necessary for flowering and fruiting - producing large, dense buds along all of the nodes that were created, in part, by the blue lights.

What's Next For LED Grow Lights & Cannabis?
While some companies are touting their full-spectrum and marketing 11+ band LED grow lights, others are opting to refine the current technology. It seems to me that the whole point behind LED grow lights is the efficiency and the fact that they are tuned-in to the precise wavelengths that are needed for photosynthesis. After all, we already understand that full-spectrum light produced by HID bulbs is inefficient, then why are some companies promoting their "white light" or "full spectrum" LEDs? In addition, adding on excessive bands of LEDs also results in a less efficient light - seems to be a step backwards, not an innovation.

I don't know exactly what the future brings for LED grow lights but I do know that there is one company doing the job better than anyone else out there. The exciting part is that the industry will continue to benefit from true innovation and research for years to come.

Wattage for LED lights.

The Cannabis Grower’s Guide To LED Grow Lights: 1W Versus 3W And Higher

The LED grow light industry is very competitive right now with many companies jockeying to position themselves as the industry leaders. This is good on one hand as the competition pushes the industry towards innovations and improvements which means a more solid product for end users. However, the downside here is that as some manufacturers push the technology towards future improvements, others focus on marketing hype as their foothold in the niche. One common place to see this is when talking about the wattage of individual diodes. While some companies offer an absurd 5W and 6W diodes, the real debate right now is 1W vs 3w.

1W VS 3W Diodes - Is Bigger, Better?
Common sense would dictate that a 3W LED would emit more intense and brighter light than a 1W. This is correct, however, this is not the whole story as some manufacturers claim. A single 3W LED will outshine a single 1W LED but it does not do so on a 3 to 1 basis. To be more clear: a 3W LED is not 3x as bright, powerful, or intense as a 1W LED. Expanding upon this, we can reach the conclusion that 3x1W LEDs will be brighter, more powerful, and more intense than a single 3W LED and the reason comes down to efficiency.



LED Grow Light Efficiency
So how can it be that 3W is really less than 3x1W? It revolves around the design of LED chips and the circuitry used to power the diode. For an LED module (chip and diode) to run, it takes a certain amount of energy (overhead) to power it up. What this means is that a 1W module will not produce an entire watt of light energy due to the overhead of powering the circuitry. Similarly, a 3W module does not produce three watts of light intensity either. The amount of overhead depends on many factors - most of which are beyond the scope of this article but suffice to say that higher wattage LED modules have more overhead in order to operate.

In real terms, this means that a good 90W LED grow light using all 1W LEDs actually operates on about 80-85 watts. That same 90W light using all 3W diodes would consume only about 50-55 watts. I think we can all agree that 85W is greater than 55W, right? This trend is evident in all LED grow lights, no matter if they utilize 3W, 5W, 6W or higher. In an industry that knows the critical role that light intensity plays in getting big yields, cannabis growers may conclude that using 1W LEDs is one of the keys to success.


Do 3W Diodes Have Their Place?
LED grow lights using 3W diodes will look brighter to the human eye. A single 3W LED does, in fact, have more penetrating power than a single 1W LED. However, when you compare apples to apples, an LED grow light using all 1W LEDs will have less canopy penetrating power than one using only 3W LEDs. 1W LEDs are more efficient, however, each 3W diode can penetrate better (as long as it is from a trusted LED supplier).

Efficiency Versus Penetration
Based on current technology, the 1W diode is, by far, the most efficient use of energy. At the same time, if you have an LED grow light made with high-quality 3w diodes - such as the 357 Magnum LED Grow Light - you will get more canopy penetration. In order for there to be more canopy penetration, you have to trade-off some efficiency in the process.

The choice to use and LED light with 1w vs 3w LEDs really comes down to the type of grow you are doing. Everyone gets so hyped up about canopy penetration when the truth is that, for most growers, it does not matter. Most closet/stealth growers keep their plants at 3 ft or less. If this describes your grow, then an LED grow light with 1W diodes can do just fine - this includes SOG and SCROG methods where there really is no canopy to worry about penetrating. Otherwise, if you are growing taller plants or want to ensure you have the most dense, sticky bud you can possibly get (even from smaller grows) you need to get an LED grow light that uses 3w diodes.

Take a minute to study the picture to the right to get an idea about how 1w and 3w diodes emit light. I use an analogy of a garden hose to illustrate light penetration. On one hand, you have a 1w diode that is more efficient than a 3w diode, yet is like using a garden hose with a kink in it - you just don't get the same amount of flow. Then you see the hose representing the 3w diode - here the hose is fully on and is able to go further than the 1w. The distance of the stream is just like the difference in penetration between 1w and 3w diodes. When talking about high-quality diodes, it is a difference of up to 4 to 1 in penetration. In other words, if an LED light using a 1w diode can penetrate 4 inches of canopy, then a 3w should be able to penetrate at least 16 inches into the canopy.

If you take the time to educate yourself on other factors such as wavelengths used, grow light height, LED beam angle, and others, it is easy to have great yields with LED grow lights.

Coverage:

The Cannabis Grower’s Guide To LED Grow Light Coverage

Over the last few months, it has become blatantly clear that the primary reason people are purchasing LED grow lights is NOT to grow tomatoes and herbs. While I am sure there are a select few visitors that do actually grow everyday food or herbs indoors and even fewer still that inquire about outfitting a greenhouse for any number of plants, a majority of site visitors are here for one reason: using LED grow lights to grow cannabis.

Dear Feds,

Neither myself or this website condones or supports any illegal activities. Information is provided for legal medical marijuana growing operations and educational purposes in the event laws change. All readers are expected to check with local laws before growing.

With that out of the way, it is safe to say that most of this site's visitors that purchase LED grow lights are doing so with the sole purpose of growing cannabis for personal/medical use. I know this and, most importantly, LED grow light manufacturers know this as well so why do most of the published coverage areas seem out of touch with reality?

LED Grow Light Coverage
While some grow light companies flat out overstate their recommended growing area simply to dazzle the visitor into purchasing, others have not-so-sinister reasons for their claims. The former is out to make a quick buck - customers be damned - and they end up shooting the industry in the foot by perpetuating negative reviews. This is especially true of low-wattage LED panels and spotlights (LED grow panel review). The latter is trying (sometimes to the detriment of its bottom line) to keep neutral by not catering to any particular customer niche, i.e. Cannabis Growers.

Coverage area varies widely depending upon many factors:



manufacturer
wattage of individual diodes
shape of the grow light
degree angle of the diodes
overall wattage of the light
intended usage
. . . the list goes on
Of all of the reasons coverage is affected, the most important is its intended usage. You see, many manufacturers publish coverage areas based on the vegetative stage. This is a very important point. When plants are in the vegetative stage, they need less intense lighting than in the flowering stage. As cannabis growers already know, getting plants successfully through the vegetative stage with LED grow lights is pretty straight forward at this point. It gets tricky when bringing your plants through the flowering stage successfully due partly to the fact that some lights are just not up to the challenge. More importantly manufacturers are eager to show clients a huge savings in electricity (thus justifying the higher entry cost) stating a 90W LED grow light can support a gardening space of 4'x4'.

Let me be blunt here - a 90W LED grow light CAN support a 4'x4' footprint but only during the vegetative growth of plants like lettuce, herbs, and some fruits and vegetables. If that is what you are wanting to grow then you will do just fine. For those of you growing cannabis, coverage expectations need to be put in check.


Big Grow Space - Little Light, A Recipe For Disaster
A common complaint about LED grow lights among cannabis growers is that they just don't get the yield they were expecting as compared to their previous grows using HID lights. Or things might look great when growing - big leaves, tons of buds - but comes up short on dry weight due to light, airy buds instead of the thick, dense buds they may be used to.

If your buds are looking like the wispy little nug on the right, then your issue could be that you are trying to grow more than your light can handle. Trying to force that 90W LED grow light to fully flower all your plants in a 4'x4' space is never going to work.

What you need to do is reduce the coverage area - generally by 50% - of what a manufacturer states the light can handle for the common gardener growing flowers or herbs for cooking. So now you can use that 90W LED grow light in a 2'x2' space (enough for a couple decent plants or even a SOG/SCROG) and come away with thick, dense bud as you see in the picture below on the left.

LED Grow Light Coverage Area Guide
I have already stated that there are many factors that can affect the coverage area of LED grow lights, here is a rough guide to what I think are suitable grow spaces for a given wattage of light. There are many LED manufacturers and many more wattages of lights so here is a list of common sizes. All lights listed are tri-band, 5 spectrum grow lights. By keeping these guidelines in mind with your growing effort, you will find that your results will match or exceed your expectations.

Light Wattage Vegetative Stage Coverage Flowering Stage Coverage
90 Watt 4' by 4' 2' by 2'
180W 5' by 5' 3' by 3'
350W 6' by 6' 4' by 4'

NASA LED Grow Light Report
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Lettuce and LEDs: Shedding New Light On Space Farming
By Todd Halvorson



CAPE CANAVERAL, Fla. -- Ask most astronauts and cosmonauts what type of food they miss most on the International Space Station and they'll tell you fresh salads are a culinary commodity craved in orbit.

That situation, however, soon could change.

Researchers here at NASA's Kennedy Space Center are parlaying the technology used to develop the latest traffic signals into a salad machine that could enable station crews to grow and harvest their own greens within the next three years.

What's more, the type of advanced lighting systems now used in sprawling airplane maintenance facilities, automotive assembly lines and semiconductor clean rooms are being tested for potential use at Martian greenhouses.

And while a human expedition outside Earth orbit still might be years away, the space farming efforts are ultimately aimed at developing artificial light sources that promise to help make future explorers self-sufficient at space colonies on the moon, Mars or beyond.




Research scientist Greg Goins of Dynamac Corp. demonstrates the sulfur microwave lamp that provides continous broad spectrum white light to plants. It can be adjusted to be twice the brightness of the noon sun on earth. Image copyright © 2001, Tim Shortt, FLORIDA TODAY.


"We know for a long-duration mission, say going to Mars, that there will be too much launch mass involved in order to take everything you need," said Gregory Goins, a research scientist with Dynamac Corp., the life sciences contractor here at NASA's coastal Florida spaceport.

"You just can't put enough in the picnic basket to survive."

So Goins and other Space Age gardeners are testing two high-efficiency light sources that future space colonists might use not only to grow food but also to generate and purify oxygen and water -- key sustainers of human life.

The removal of carbon dioxide from a closed environment is another added benefit.

"Plants are the only way we know of where we can generate enough food, water and oxygen to support humans for such a long flight because we know re-supply is not an option. And so plants are a very appealing approach to use," Goins said.

"But in order to use plants, you must have an energy source, and that energy source is light," he added. "And the lights we use in our homes are not energy efficient enough to get the job done. So that's why we're developing these innovative technology lights."

Take the common incandescent bulb invented by Thomas Edison more than a century ago, or the type of fluorescent lamps first developed in the 1920s.

Both contain electrodes that burn out, so the lights must be periodically replaced. And both gobble up electrical power -- a precious commodity in space -- while generating heat, which must be dispelled from closed environments such as spaceships and space stations.

"Standard light sources that we use in homes and in greenhouses and in growth chambers for controlled agriculture here on Earth are not efficient enough for space travel. Not only that, they don't last a very long time," Goins said.

"And in space, heat is like trash. You make it, and you've got to get rid of it, so we don't want heat. We want light."

In recent years, dramatic improvements in lighting technology have provided NASA and its support contractors with new means to develop low-power space-farming systems that will last the life of a building -- or a greenhouse on the surface of Mars.

Working in plant growth chambers the size of walk-in refrigerators, Goins and other plant physiologists here are experimenting with blue and red Light Emitting Diodes, or LEDs, to grow salad plants such as lettuce and radishes.

Similar to devices now used to manufacture advanced traffic lights, the LEDs enable researchers to eliminate other wavelengths found within normal white light, thus reducing the amount of energy required to power the plant growth lamps.

The LEDs generate less heat, and while leaves take on a black hue due to the lack of green light to reflect, the plants grow normally and taste the same as those raised in white light.

"What we've found basically is that we are able to limit the amount of color we give to the plants and still have them grow as well as with white light," Goins said.

"Being plant physiologists, we know the chlorophyll molecule well enough that we know which wavelengths most efficiently stimulate plant growth, and it turns out to be blue and red. So I don't have to devote energy to green light, and my plant will grow just as well."

Nevertheless, green light can be added for aesthetic purposes.

"So if you're in orbit for a long time, not only do the plants taste good but they actually appear as plants do on the ground," Goins said. "But we also know we can eliminate the green light if energy costs are a concern -- and they usually are in space travel."

Another bonus: The LEDs can last the length of a round-trip mission to Mars, unlike incandescent or fluorescent bulbs, which require frequent replacement.

A second long-lasting light source being tested here: Sulfur Microwave Lamps.

Now used to light up large airplane hangars, shopping malls and gymnasiums, these high-performance lamps were first developed in 1991 and one day might be used to light conservatories on the surface of Mars. "The microwave lamp is a technology where we're thinking about a large-scale system like a greenhouse on Mars, where we can illuminate a large growth area," Goins said. "It is the most efficient electric lighting source known to man."

Twice as efficient as other high-intensity sources, the microwave lamps can generate as much light as the noonday sun. The light in fact is so bright that it can be funneled through pipes and then distributed over large areas, such as a hothouse on the Martian highlands.

The lamps also are dimmable, so space colonists would be able to attenuate light within their greenhouse to match the growing cycles of their crops.

"When there are small seedlings, you don't want a very bright light," Goins said. "But then you could turn the lamps up accordingly as the plants got bigger."

The bulbs, meanwhile, are simple hollow quartz spheres with sulfur and argon gasses that are energized with microwaves. And with no filament to burn out, researchers think the lamps could prove to be the perfect light source for a space colony.

"Theoretically, the microwave lamps should last for years and years, and we've found that to be the case," Goins said.

With an investment of just $80,000 to $100,000 over the past three years, the high-tech lighting systems here have been used to grow potatoes, sweet potatoes, lettuce, spinach, radishes, wheat onion and a whole plethora of herbs such as marjoram and parsley.

The plants typically are grown hydroponically, or without soil. Water laced with a nutrient solution is circulated within plant growth chambers that are lit up with either the LEDs or the Sulfur Microwave Lamps.

And while greenhouses and space colonies on Mars are still a long way off, Goins said a specially designed LED plant growth chamber should be ready for launch to the international station within the next three years.

"I would probably call it a salad machine," Goins said.

About half the size of a tall file cabinet, the plant growth chamber would enable station astronauts and cosmonauts to grow and harvest salad greens, herbs and vegetables during typical four-month tours on the outpost.

"Now this salad machine wouldn't be built on a scale large enough to actually give the crew all the food they need," Goins said. "It would be just a supplemental endeavor in the near term."

But it would have psychological benefits for station crews, too.

"When you're inside a can for several months, I can see where having something green and living onboard would be very appealing," Goins said.

"So to have an herb garden or a salad machine actually on the space station would make the stays in space more pleasurable," he added. They would just love that."