I started this journey after after testing several of the low cost grow lights being imported from China. Every one I tested was over hyped, low powered junk. By the time I got tired of fooling with the Chinese junk 3 watt LEDs had come out and I realized that with the right cooling a lot of these could be mounted in a very small space. You can read more about this project on our www.grow-sun.com web site.

Fast foreword 2 years and industry has finally released more affordable LED replacements for screw-in type light bulbs, including LED flood lights. And while in LOWES looking at LED light bulbs one day I wondered if my Grow Sun grow light had been out flanked by technology? I wondered of a lower cost LED based grow light could be put together out of production LED lights? Well, the answer is yes, you can put together your own high intensity LED grow light, and this article shows you how.

We decided to sell a fully assembled version of this grow light fixture. You can find more details HERE.

Step 1: Select the LED flood lights you want to use

I did a lot of shopping around the big box stores and picked out a LED flood light I liked. It's a SYLVANIA ULTRA LED flood light. The output is rated at 520 lumens at only 8 watts of power and because of the relative small size (2.5" across) I thought I could get 6 mounted to the housing I had in mind.
<p>The output is rated at 520 lumens at only 8 watts.</p><p>----</p><p>..or 1560 lumen at 24 watts, or 65 lumen per watt</p><p>FYI:</p><p>LED, $2.50 apiece if one buys four, 800 lumen at 8 watts or 100 lumen per watt</p><p><a href="http://www.homedepot.com/p/Philips-60W-Equivalent-Daylight-A19-LED-Light-Bulb-4-Pack-460329/206557595" rel="nofollow">http://www.homedepot.com/p/Philips-60W-Equivalent-...</a></p><p>Fluorescent, $3.25 apiece if one buys four, 1600 lumen at 23 watts or 70 lumen per watt</p><p><a href="http://www.homedepot.com/p/Philips-100W-Equivalent-Daylight-Deluxe-T2-Twister-CFL-Light-Bulb-4-Pack-E-433557/204855102" rel="nofollow">http://www.homedepot.com/p/Philips-100W-Equivalent...</a></p>
<p>You made a great project and I'm going to buy the stuff to do this today.</p><p>I've been reading the comments, and wow man. Chill out and maybe try the project before spouting all kinds of hate about full spectrum lights and raving about how useless all the wavelengths other than red and blue are. Apparently you're all scientists, so do some science. Maybe don't blindly follow online charts and papers, and perhaps do your own experiments? You know, science? Test your hypotheses.</p><p>If full spectrum LEDs work for the author, and they work for me, then the project is a success (Scientific Method, and all that...). If not, then I guess I'll have 6 more LED bulbs to make my place that much more efficient.</p>
<p>I found a perfect solution, these people<br> are great at their service and provide a full line of LED products including 'LED grow products'<br> that have uniform coverage. Can&rsquo;t beat their pricing, to build one that<br> is safe from fire and electrical hazards, not to mention the guarantee <br>that comes with it.</p><p>We used them for sprouts, and simple greens in our home, however they<br> state that they have experimented in full fruiting plants with success <br>as well.</p><p><a href="https://justledus.com/" rel="nofollow">https://justledus.com/</a></p>
<p>some plants need different spectrums for different stages like our 4 seasons when the sun closer and futher we are getting different spectrums as the 4 seasons so unless you want to waste time and money on house plants that dont produce and give back your normal house lighting is fine maybe open the blinds but brightness on single spectrum house/flood light isnt whats going to make a healthy plant and that set up would be too bright for normal house plants now on the smokeable kind of plants you would want high uv's with lots of blue white and purple specs for vegi stage and for flowering whites orange reds and about 3 weeks til harvest time you would also introduce med to high uv to increase potencey and thats opitional so check the specs and research the plants to see witch type of specs they like and at what lumination and for how long </p>
<p>man before any of yall go out and a bunch of flood lights from the hardware store do your research first those lights are only giving off one spectrum maybe 2 and some plants need sertian spectrums to be heathy or even to bloom flower or produce fruit yeah if you want to spend money</p>
<p>How exactly is this a grow light? It's 6 normal &quot;Living room&quot; LEDs as far as I see, you're basically wasting most energy on the green spectrum plants don't even need. If I just assume that each of the lamps above is $10 (which they for sure, if not much more), make your project at least $60 for the lamps PLUS the entire DIY work. Sorry, but then even a cheap 300W+ China LED grow light which can cost as little as $70 (6 Spectrum with 3W or 5W LEDs) seems a much better choice to me than your DIY project there. And might ironically even be cheaper ultimately.</p>
<p>Yes, it's a project based on normal living room LED lights but that was the plan all along - to build a grow light from material you can buy from LOWES. This is a &quot;grow light&quot; because of the high concentration of light from one source. You won't find a off the shelf light that produces as much light in such a small space.</p>
<p>Very creative i found only 2-3 sources over the net who suggest using simple LED bulb as a grow light.</p><p>are flood light and spot light are different ?</p><p>What are the different names for the LED flood light </p><p>What should one what out for before buying ?</p><p>Can you suggest more alternative buy (on the LED bulb ) with amazon uk / us ?</p><p>the product you made is sufficient for how many plants ?</p>
<p>We are in the middle of a LED light revolution, with light technology evolving so fast that even models introduces three months ago seem obsolete. My best advice is to limit your selection to floodlight style LED bulbs, then buy whatever produces the most lumens per watt, then set up as many lights as you can afford.</p><p>&quot;How many plants&quot; depends on what you are growing. The light I made grew two tomato plants just fine with some help from an outside window. The same type plants in the same window grew too tall too fast, so I know the lights made a difference. We don't grow pot here, it's still illegal in Alabama.</p>
<p>Hi!</p><p>My name is Susana Barker, i am a housewife but I like the <br>high-tech very much. I want to find a best led to grow all tree in my garden. I <br>like this article very much, this article is very helpful for me, i will share <br>this post to all my friends. The best same site, I found at Google: <a href="http://ledgrowlightsguide.tk/" rel="nofollow">http://ledgrowlightsguide.tk/</a>. Thank <br>for shared!</p>
<p>Also, just as a side-note, LED technology, for growing but also for lights at home is fortunately progressing like crazy the last few years. I believe that today you can actually get &quot;decent&quot; LED grow lights without spending too much money. I constantly read about people warning about cheap &quot;China LEDs&quot;...but then I bet any money that pretty much ANY manufactured has them produced in China and uses the same parts and LEDs, saying that your $800 super-grow light might necessarily not be that different than the $100 &quot;cheap&quot; one, I mean ultimately most of this stuff is made in China...just rebranded and then you pay premium just for a name. My $0.02</p>
<p>Be careful when value shopping because but there are a lot of cheap grow lights on the market that don't produce much light and are grossly misrepresented.</p><p>Also, this article was written just before the bottom fell out of the consumer LED market. Right now you can buy a LED flushmount ceiling fixture from LOWES for about $36 that I believe would make a great grow light. I also believe that these are a better deal than any specialty grow light you can buy.</p><p>One advantage of building a fixture like the one in this article is with the right LED spot lights you can generate a lot of lumens (light concentration) from one spot and this would be important to some growers.</p>
uhm NO<br><br>cheap closeout multisocket strips bathroom strips (those things u see over mirrors a lot) and/or 2:1 Yconnectors and/or 4:1 splitters<br><br>2015 prices paid:<br>$3 / 950 lumen LED bulb for COOL WHITE/DAYLIGHT 5000-6500K<br>$0.25-0.59 / 1200-2400 lumen CFL for SOFT WHITE (cfl deals too nice to go led for 2700-3000K, also cfl soft whites have 65-70 lumens/watt, which while nowhere near led 5000k's ~100, is just a hair worse if it all than the 60-80 lumens/watt out of common cheap soft white leds...plus fixtures and connectors are pricier than bulbs these days, and good CFLs sit in the 23-40w/1200-2400 lumen ranges vs led's 9-11w / 600-950 lumens, making mixing in some cfl good common sense)<br>$2.50 / Yconnector 2:1 splitters<br>$5/ closeout 3 bulb strip fixtures, even had a semblance of a reflector albeit bronze coloured<br><br>currently running clusters of hanging yconnects, havent installed the 3 socket strips yet. bulbs totalling ~200w, half LED half CFL by wattage, put out measured lows of 10,000k edges to average 30,000- 40,0000k lux AT FOLIAGE for most plants in a black and yellow aero tote. measurements supported by the most robust growth seen at the brightest spot.<br><br>no leaf burn. cheaaaaaap. and puts out the kind of foliage surface lux people look for out of MH and HPS (desirable range often stated as 25k-50k - my 30k-40k for most positions foliage fits right in with that), simply cuz led can be run point blank and cfl a mere 2 inches away or so, and thus their lumens actually deliver. while mh lumens dissipate since its temp requires running it from way far off..
<p>Congratulations, that's a great find! But not everyone finds closeout items to fit their projects.</p>
I don't think the LED Lights were a good choice. The lumens just don't matter alone. If you want a nice 200 gram steak, you won't be too happy with 2 kg sausage, would you? Like that, light with 3000 K does not have the right wavelengths of light that plants need. With normal fluorescent light tubes, you want to go as high as possible, like 4800K or 6400 K, which I use, or you can mix 2 6400 with 1 4800. But light tubes give off a whole mixture of wavelengths, that is well known. LEDs work completely different and no one knows which wavelengths your lamps have. That is why professional LED Grow Lights use red and blue LEDs in a certain mixture.
<p>I put a tremendous amount of research into lighting and plant growth. I learned that plants are sensitive to all light wavelengths not just blue and red. I also learned by doing my research that the light sensitivity graphs that are scattered all over the net are somewhere between misrepresented data and outright lies. What I discovered through research is the graphs that show high sensitivity to red and blue light and almost no sensitivity to green light misleading. Find the real light sensitivity data and you will see that the bottom 2/3 of any graph that shows only red and blue has been cut-off and that plants are sensitive across the entire range of visible light with red and blue being the most sensitive areas.</p>
<p>Alas, but this is not so. Just 130 years ago a scientist Timiryazev studied this process. Important only the red and the blue part of the spectrum. Green indifferent. Sometimes add a little white. For the aesthetics of the human eye. But plants are indifferent. The white light is wasted much energy.</p><p> I successfully grow salad lamp 20W (15W red LED and 5W blue.). This is enough for the area of 40 x 40 cm</p>
20w &quot;daylight white 5000k&quot; led, as long as pointed correctly, can output absolutely INSANE amounts pf lux at 40cm x 40cm
<p>Thanks! I'd be interested in you doing a write up on this!</p>
<p>As in, you want to build one or you want me to loan you one so that you can use the light and report to the rest of us?</p><p>I had originally intended this to just be a project to share, but based on the initial interest in these instructions I wonder if we should start selling light kits?</p>
<p>Here's a variation on the graph Costarus posted</p>
<p>I've seen this chart in many variants but what the publishers don't tell, or at least what the original publisher does not tell is the lower part of the chart is cut off and the range is re-scaled. Find the actual data and you'll see that plans sensitivity to green is not close to 0 as the chart leads you to believe, but plants are about 1/2 as sensitive to green as they are to red. The problem is this chart has been posted on the net and has gained traction and is now taken as &quot;the gospel truth&quot; for lack of a better term. I'm sure you've seen the insurance commercial - the one where the lady states &quot;if it's posted on the internet, it must be true?&quot;</p><p>Get away from the &quot;light fixture marketers&quot; and turn instead to sources hosted by educators (Universities &amp; such) and you see the real plant light sensitivity curve. It took a few minutes to wade through the HPS, MH and LED marketing sites to get to university hosted sites but right away I found a chart of the actual plant light spectrum sensitivity. It's the second image I uploaded. The image shows a dip around green but the dip is no-where around 0!</p><p>Also, the human eye sensitivity to light bell chart in this graph is dead wrong. I added the correct graph that does show our eyes are more sensitive to green but is nothing like what's in the previous chart.</p>
<p>Not to pick nits, but since you infer that I'm gullible and only read marketing drivel: the scaling of the charts are different. Yours aren't really labeled well and contain no citations whatsoever. Regardless, it appears that in your second chart the black line is chlorophyll blue absorption wavelengths with the peaks at A and B just as in the one I've posted , while I have no idea what the green line is. You've also taken issue with &quot;human eye sensitivity peak: perceived white light&quot; in the chart I posted and then posted a chart showing almost identical sensitivity, just scaled differently.</p><p>As far as scholarly articles here's one of the several I looked at before posting: <a href="http://plantsinaction.science.uq.edu.au/edition1/?q=content/1-2-2-chlorophyll-absorption-and-photosynthetic-action-spectra" rel="nofollow">http://plantsinaction.science.uq.edu.au/edition1/?...</a><br>an excerpt of which is &quot;Upper curves: Diethylether solutions of chlorophyll <em>a</em> (Chl <em>a</em>, solid line) and chlorophyll <em>b</em> (Chl<em>b</em>, dotted line) show distinct absorption peaks in blue and in red regions of the visible spectrum (redrawn from Zscheile and Comar&rsquo;s (1941) original data).&quot; as well as &quot;Leaves absorb visible light very effectively (&gt;90% for all wavelengths combined; solid curve).Wavelengths corresponding to green light are absorbed less effectively (absorptance drops to c. 0.75). Beyond 700 nm (infrared band) absorptance drops to near zero, and forestalls leaf heating from this source of energy.&quot;</p>
<p>I did not intend to infer that you are gullible, my comments are for everyone to read &amp; not just you. Unfortunately there is a lot of marketing hype on the net and I'm just stressing, or maybe over stressing that point.</p>
<p>Actually, I was replying to Costarus' comment. I'd like to see more about what he's using for the targeted wavelengths. After my comment I did a little looking around online and this appears to be the current &quot;state of the art&quot;.<br><br>After my admittedly cursory reading around I am curious how much of the 425-465nm and 640-660nm spectrum is being emitted in the configuration you've used. I understand that your goal is to open up the area to less technical people, but I've found some of the red/blue LED grow lights online for around $20 each.</p>
<p>Buy them, use them, please let us know how well they work!</p><p>I bet when you get the lights in they will be powered by small power supplies that can't deliver any real power. These are the type lights I mentioned at the beginning of my article.</p>
<p>years ago, I was using exactly the same 1000 watts HPS lights that every other commercial grower is using, most growers were getting 0.5 pound ~ 1.1 pound of harvest per light, I was getting just over 2.0 pound per light, there's a lot more to growing than just lights. If you do it right on the entire process, simple HPS works just fine.</p>
other way around.<br><br>ALL white leds emit significantly in the entire visible spectrum, with high blues and reds, and comparatively lowrr green and yellow. meanwhile, fluoros and cfls emit three HUGE NARROW SPIKES in R G B and barely anything else
Lumens can matter alone just fine. HPS or MH grow lights dont have nor need a perfect full spectrum to grow from seed to fruit because of the pure amount of lumens they output. If you're serious about growing, you switch between the two to simulate summer/fall sunlight though (spectrum as mentioned). The point is, lumens CAN cut it. However, I dont know how much you'll really grow with only 3000 of them.
<p>Lumens are not the important number when it comes to growing. LUX is the correct identifier. Believe it or not, there is real science behind this. You need to provide plants the correct color ranges for photosynthesis and enough LUX to make it happen. Science says these are in the red and blue range. (see chart above from costarus)</p><p>It's hard to admit, but even if your light works for a grow light, there are MUCH better ways to do this.</p>
<p>Metal halide (predominately blue) and <br>high pressure sodium (predominately red) bulbs have been the standard <br>for indoor growing for how long? Neither of them give off a perfect <br>red/blue spectrum, yet you can grow from seed to fruit under either <br>because of the sheer amount of lumen output. As I pointed out in <br>another post, people that really want the best results start with metal halide bulbs and finish with high pressure sodium to simulate the change in seasons.</p><p>Conversely, <br> most reviews of red/blue LED's were for the longest time, poor. They <br>simply didn't provide the lumens even though they were the optimal <br>spectrum colors. They're definitely better as of late through <br>technology improvements (IE More juice!). But still, I stand by what <br>I've said that you'd be better off with true high power LED's like the <br>Cree cxa3050 (something I'm currently building with myself).</p>
Of course, as long as the right wavelengths are at least there, you can just give off more light and it will eventually be sufficient at some point. But that is of course not the best way. To get back at my steak/sausage example, if I give you 2 kg meat of which 50 gr are the steak you want, of course I can just give you that four times so you have 200 gr steak. No problem.<br>Metal halide and sodium pressure lamps are just easy to get, and known technique.<br>If you would try to grow plants with a green laser, even 100000 Lumens would not be okay for your plant, it just would get quite hot. So if my lamps give off just the right spectrum, I can save energy because I don't have to emit the waste, the useless light.<br>So, with mixed spectrums, lumens can kill it, but that's not the clever way.
<p>As I stated earlier and I will state again. Because one of the goals of this project is to make it build-able by <br>anyone with local hardware and you aren't going to find a 50w LED spot <br>light at your local Home Depot, Lowes or Menards store.</p><p>Also, the person most likely to build this project is looking at buying or building a &quot;grow light&quot; to grow a few plants indoors or start seedlings for his garden. The folks shopping for HPS or MH grow lights as well as those looking for high wattage red &amp; blue LEDs is probably not going to be interested in building one of these lights.</p>
I'm interested, but not for a grow light. We have a large torchier that we've owned for 20 years now, and has seen everything from a 300w T3 halogen, through a 150w PAR38 reflector, to a twin-circline T8 fluorescent fixture (there worst of the bunch in terms of light quality, thanks to the incomplete spectrum, but the best in terms of heat output). This idea might just work for me.
<p>The trick will be to adapt a fixture to screw into your floor lamp. Maybe you can build something from a screw in base, a box and 4 sockets, kind of like a 1 to 4 adapter that you screw into your fixture?</p>
In case you didn't figure it out, I did all of those adaptations. so, yes, it'll be something akin to yours. http://i.imgur.com/iyzaw0o.jpg is the fixture, except I pulled everything apart and flipped the base, to act as a reflector as well as allow it to sink into the fixture more. I'll likely use that plate, and see how an array of LEDs will work I'm guessing I need at least 4000-5000 lumens to make enough light, the 500w T3 worked great, but the heat output and power consumption don't make it worth it.
<p>Interesting, that's a picture of an old Circle-line fixture. I'd like to know know things ultimately work out.</p>
precisely. cost me $5 after my employee discount, the bulbs cost more than the fixture. I'll get pics of the fixture shortly.
<p>Love this - very easy to follow, and you make it sound very doable.</p><p>I would still prefer LEDs over CFLs, since CFLs contain mercury and thus cannot be discarded in the trash. They must be taken to a hazardous waste collection site (Home Depot takes them here in PDX, and there is also a county collection site). </p>
<p>we don't need so much power, it's all about the angles, i have a 7W plant arm with no fan - no heat sink... check it out. you can attach these plant arms to any pot !</p><p><br></p><p>can be powered via USB, rechargable battery or solar even !</p><p>visit my profile; <a href="http://www.instructables.com/member/0bios0/" rel="nofollow">http://www.instructables.com/member/0bios0/</a></p>
<p>Aside from (or in addition to) Lumens and LUX, could someone add information about CRI ? It would seem that higher CRI would mean more balanced light. So to that end why not build up shop lights with high-CRI, high Lumen T8 bulbs that also use low power?</p>
<p>The higher the CRI rating the more natural color rendering appears to your eyes, with 100 being the same color rendering to your eyes as natural sunlight. But this does not mean the light is producing the same spectrum as the sun or that a high CRI rating is the best light for your plants. Here is a good article about CRI.</p><p><a href="http://lowel.com/edu/color_temperature_and_rendering_demystified.html" rel="nofollow">http://lowel.com/edu/color_temperature_and_renderi...</a></p>
Thanks for the educational link. It doesn't seem to make sense to me, however, that if a light produces the same spectrum as the sun it may not be the best for one's plants unless plants actually prefer higher or lower K lighting (i.e., with either higher or lower visible wavelengths filtered out, respectively). Is that the case?
<p>Science discovered a long time ago that plants process some light colors better than others. And if you have control of the brightness of different colors why not tune your light source to benefit your plants? Anyways, that's the theory and the reason you see oddly colored grow lights. This project is all about building a grow light from off-the-shelf lights and my theory is if you get the light bright enough the plants will grow well anyways.</p>
<p>This paper ( http://www.plantphysiol.org/content/46/1/1.full.pdf ) gives you the actual data in addition to the graph (on page 4). Although it's only for one type of plant (bean), it has a pretty good discussion and the concept is what's important. Note that it's based upon photons, not lumens. The curve measures how many photons are required to produce CO2 at each wavelength, not just what seems to be absorbed. Since this reaction and the production of ATP form the basis of the energy flow into the plant, it's what's really important. The long wavelength red is about 1/3 more efficient than green, so you're right that the curve doesn't drop to 10% as in the absorption spectrum, but the definition of lumens is so heavily weighted to the green that it makes the miscalculation even worse (as argued by Coffeinated, above).</p><p>If you add up the red, green, and blue in the chart you show for cone sensitivities in the retina, you end up with a curve that has an even more pronounced peak (because of the overlap with the red and blue sensitivity curves). That doesn't really matter though, because the lumens you're talking about are a measurement standard, not the actual response of your retina. That curve does have a peak in green, so light from bulbs intended for use as general purpose lighting get more &quot;credit&quot; for photons that have a wavelength that is not as useful to plants, as demonstrated by the photosynthetic action spectrum described in the paper.</p>
<p>Forgive my ignorance about light meters, because I haven't tested it yet. If I was to make 2 of these units and put a light meter under both of them lit up, does that mean I'll get 6240 lumens right beneath them or will it still be 3120. Ie, adding extra 520 lumen bulbs pumps up the lumens on the meter when tested? Are the bulbs additive in brightness, or will they each show just 520 lumens of light when tested at say 4 inches away under the centre of each light?</p>
<p>Total light produced will double and the brightness definitely will increase but measured lumens will depend on where you measure. Unlike sunlight where the light is pretty much a parallel beam because of our distance from the sun, lumens will decrease as you move away from any bulb.This is because with any light source but the sun, light spreads as you move further away from the source. Professionals who grow under artificial light understand this and they measure their light levels at the leaf level.</p>
<p>&quot;This is because with any light source but the sun, light spreads as you move further away from the source&quot;</p><p>That's not true Tom. The Inverse Square Law applies to all electromagnetic waves, of which the Sun is one.</p><p>The illustration below is the correct one. </p>

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