I'm a newbie to seed-starting and am trying to find info re: LED lights vs. 'older' grow lights. Don't want to ask re-run questions if there is already a link/thread about this, but I sure can't find any with the change in search engine! Any info welcomej, and/or any leads toward other chats. Thanks SO much!
I was curious too if LED's would work. There are recommendations when using florescent bulbs to do half in Cool bulbs (blue light) and half in Warm bulbs (red light) to give a fuller spectrum of light for seed starting & seedling growth.
So I googled LED spectrum of light to see what came up. It would appear that you would need to use a combination of Red LED's & Blue LED's as grow lights. I looks like the white LED's would not be recommended for grow lights. LED's do not produce heat, so that is one benefit and of course there is way less power consumption .
The advantages of LED lights are potentially many. LEDs with specific wavelengths can be used so that light emitted is ideal for plant growth be it seedling (more in blue spectrum) or reproductive (red spectrum). Most of the LED grow lights use a balance between the two for a balanced light that is good for all stages of growth. Joanna is right that many people recommend a mix of cool and warm florescent lights for general plant growth, but if all you are doing is germinating seeds/ growing seedlings, cool light alone is perfectly fine. You need more of the red spectrum if you are trying to promote reproduction (blossoms and/or fruit).
LED lights operate on DC current, not AC so the amount of power used is very low compared to "typical" plant lights. (an AC/DC transformer is part of all lights). In addition, LED lights are diodes, not bulbs, so their life is incredibly long compared to traditional bulbs of any type. They also emit almost no heat so controlling temperature is easier (or harder if your setup uses lamp heat to warm seeds/seedlings). Light panels for plants are not single LEDs, rather they are an array of dozens/hundreds of individual diodes.
Now the bad news - LED grow lights are expensive. One company that I looked at on line has a light that will cover ~ 1.5 sq ft for just over $50. That equals approximately the area of one 1020 flat although the dimensions don't match as the lights are 12.25 inches square. I use florescent lights to germinate/raise seedlings and I would need two LED light panels to replace each 4 ft light I currently use. For the price of the two LED panels, I could purchase 10 new four foot florescent lights so for me in the short run I'll continue with the florescents that I have. Of course you would have significant electrical savings (although low already) and a much longer life with the LED. If I were to replace the eight florescent fixtures I currently use, it would cost over $800 to buy LED panels.
One use for which I could justify the cost of the LED is if you are raising house/flowering plants and don't get enough natural light for them to thrive. In that case the cost might be worth it to you so you could produce beautiful blossoms on your plants all winter long.
LED technology has been around for many years but has only recently moved into the home consumer market (mostly for Christmas lights and under the cabinet lights). Hopefully, in a few years the costs will come down on LED plant lights and we can enjoy some of the benefits they offer.
One final note, a while back (within the last 6 months) I read someone was trying to make their own LED panel using clear Christmas LED lights by attaching them to a board and hanging them over plants. I don't know how that experiment worked, and I would caution against that as you don't know what wavelength those LEDs are emitting. LED lights emit a very narrow spectrum of light hence the need to combine types of lights in the commercial light panels. The spectrum emitted in Christmas lights might be ok for plants, but could just as easily not contain the required wavelength for plant growth and could turn into an expensive experiment.
To summarize, LED lights are a fantastic technology that are energy efficient and environmentally friendly but at this time, probably too expensive to be used for seed germination alone.
Thank you so much trc65. I appreciated the detailed analysis of pros and cons. The LED info I was finding online (outside from you DG'ers) either was very technical, DIY, and/or mostly marketing. I haven't started seeds indoors for years,, and, due to major life transitions, have had a wonderful time this past year beginning a new life, with an old passion-playing with dirt and plants and ideas...; I now have a tiny greenhouse (inside my enclosed breezeway)-more like a 'greenspace:-see my pics in the fuschia forum if interested...and am trying to make decisions about new flourescents, etc. having had very limited options 25 years ago. My main goal was to over-winter my fuschias initially, but now I've, of course, been drawn back into seed-starting.
I am not trying to keep the fuschias in bloom over-winter, so that issue doesn't apply.
I bought a 225 LED light panel on ebay for about $27 to try them out and I hold it above the germination tray about 18 inches and it works pretty well so far. Not really emitting much heat although I have it set up in a pretty warm room to begin with so it's hard to tell if they're even emitting any heat at all. I'd recommend them. I'm going to set up 6 light panels altogether on my indoor greenhouse here pretty soon and start germinating some seed in possibly peat pellets and peat trays. Should be enough to cover 9 trays altogether for my setup. Next thing to track down is some seedling heat mats.
Can you post some specifications on your light panel? I think a lot of us are interested in the technology. I'm curious on manufacturer, panel size and wavelength/mix of the different diodes in the panel.
Here's info from the page the seller had for it. Hope this is useful because I personally couldn't make heads or tails of it because I'm new at this.
2009 Xen-lux LED Single Grow Light Panel
Number of panels: 1
LEDs per panel: 225
Total LEDs: 225
Color: Red/blue mix
Power per panel: 14w
Panel size: 12.25" x 12.25"
Panel height: 1.5"
Red wavelength: 630 nm
Blue wavelength: 455 nm
Blended wave: 652 nm
Rec. coverage: 4 sq. ft.
Max. coverage: 65 sq. ft.
Use: Indoor growing
Shipping weight: 4 lbs.
Features & Benefits:
Each light contains 225 pieces, 6-centiwatt, 5mm LEDs
Red/blue ratio of 11:4 (165-red, 60-blue LEDs / panel)
Precision red LEDs from High Power Opto (flowering)
Precision blue LEDs from Bridgelux USA (growth)
True optimized spectrum with tight-tolerance LEDs
Unrivaled chlorophyll/carotenes/xanthophylls absorption
Uses wide-angle LEDs for max coverage & output
Silver-reflective board under LEDs increases efficiency
No infrared rays or ultraviolet radiation to stunt plants
LEDs emit light without using filaments; light runs cool
Built-in, ballast-free, power supply circuitry
PC board has oversized, ¼" wide traces for min. loss
10-years or more life-expectancy with minimum decay
Operates on 120 volts; standard USA cord included
Built-in, pre-drilled holes for easy mounting & hanging
CE & ROHS compliant
Thanks edewitt, that's exactly what I was looking for. I have had thoughts of wiring up my own LED panel, but I wasn't sure what kind of mix of red/blue to use or what wavelengths to use. Although, if they continue to drop in price, it won't be worth the trouble to make my own.
I have been using cheap(from home depot or Lowes) regular 4 foot shop lights bought in boxes of 10 for under $15 for 11 years and have very sucessfully started more than 150 varieties of annuals and perennials. I start my seeds on propagation mats, with the light above in Jan and Feb, and transplant into 6 packs, and as they grow into 4 or 5 inch pots and in may and June have potted up 2-3 thousand plants, sell them off my driveway, yard sale like and they go at $2.50 each or 5 for $10. Have many shelves set up with these cheap lights. Put the plants on my front porch,(southern side,) to harden off as soon as I see other pernnials emerging from the ground. It works for me, I do see a spike in my electric bill of about $150 a month, but it pays for itself, wonder if I tried the LED"s, never heard of this. do you think I could save money? Thank You Annette
kobwebz, You would definitely save on your electricity bills, the light mentioned above operates on only 14 watts. Many websites selling the LED lights advertise electricity savings of 50-90% depending on the fixtures you are currently using. However, the cost of purchasing LED lights is much higher than standard florescent lights. You'll have to figure how many LED fixtures you would need to replace your florescent lights and how long it would take in electricity savings to pay for them. Also the life of LED fixtures/diodes is extremely long!!
I will have to wait this one out until they get cheaper, when I'm in full swing I have about 50 shop lights going. Love the part about no uv. Went to the website joannabananna mentioned above, and thought it was interesting that you get a free package of plant magic magic the purchase of 1 light. I've never been one that fertilizes. Also have never had the lights I use burn the plants or had seedlings dry out, use holeless flats and bottom water, about 1/2 gallon every week while they are still in the 6 packs. I bottom water them.
I'd like to renew this thread and see if anyone cares to share their experiences with LED light panels. After this discussion last year, I spent quite a bit of time thinking/researching these lights but I decided not to buy any of them as the cost would have been way too high to replace the eight florescent fixtures I already use. Now that I'm beginning my seeding season, I am again thinking about purchasing one or two fixtures to try.
I was in Sam's Club this week. They had little LED light bars to use as under-the-upper-cabinet counter-top lights. They were pre-wired and it said you could connect up to 7 in sequence and run them all off one plug. I forgot the exact price - $18-20? for one. I couldn't figure out how the light output compares to a fluorescent - I need to start thinking in Lumens instead of watts. I was thinking of going back and getting a 1-2 to experiment with - as counter-top lights in the kitchen, or as workbench lights in the garage, or as a permanent "night light", or as a plant light in the basement. I thought they might be good for seedlings that like cool-colder growing conditions, since they put out even less heat than a fluorescent. I don't want to spend a lot of money on an experiment right now because I suspect the price will go down over the next couple of years. Meanwhile, I already own enough fluorescents and I doubt they are going to wear out in the next few years.
pollengarden, you are definitely correct on the heat front, LED lights do put out very little heat. A couple of things that everyone needs to think about before making the jump into LEDs. First is the wavelength of light needed for plant growth. I touched on this a little bit in my post earlier in this thread. To summarize, colored LEDs are very specific in the wavelength of light they emit and you must be sure to match the LED to your specific needs - vegetative, reproductive, or some combination of the two. White LEDs do emit light over a range of wavelengths but the majority is in the blue wavelength. Most of the LED panels that I have looked at for plant growth are a combination of red and blue diodes that are chosen for their specific wavelength. I have a feeling that while white LEDs produce a broad spectrum of light they are very inefficient in providing the spectrum(s) specific for plant growth.
Another consideration that you mention is the issue of light intensity. Unfortunately, I can't offer much information on comparing LED to other lights. It can be confusing as LEDs are measured in milicandellas other lights are measured in lumens/watts and these measurements relate to what humans see, not what plants need.
A final consideration in using generic LED lights for plant growth is the viewing angle of the individual LED. While traditional lights used for plant growth (florescent/incandescent, etc) emit light in all directions, LEDs emit light in a viewing angle ranging from 15 to 120 degrees (spot to wide angle). This consideration is important in positioning the lights close enough to get the needed intensity while far enough away to get complete coverage from diode to diode.
After reviewing everything I just wrote, I hope others can make some sense of it. The bottom line is I wouldn't spend any money buying LED fixtures unless they were specifically made for plant growth. There are just too many unknown variables with "generic" LED fixtures made for other uses. That said, I'm not sure that I would spend any money buying LED panels made for plant growth either. I think they are still too expensive compared to the florescent fixtures that many of us use and their benefits don't outweigh the cost at this time. I would however, encourage anyone who is using LED growth panels to chime in here and let us know what experiences you have had using them.
I have been hemming and hawing about these LEDs for years, but like you, trc65, I think they are still too expensive and I am sticking with my shoplights. The shoplights do cause a spike in my electric bill--not $150 like kobwebz has, but enough to be noticeable, especially when the lights are combined with using propagation mats. I hope the LED price does come down in the future. So far, not much.
Like kobwebz, I use cheap 4' flourescent fixtures from Lowe's and use daylight spectrum flourescent bulbs, also purchased at Lowe's. I think they were around $20 for a ten-pack of bulbs. I have only 4 shelves with 2 fixtures per shelf, or 16 bulbs total, which aren't running full blast til March or so, and a couple of heat mats which are only running for January/February, and I've only noticed a small rise in my electric bill.
Now guys, what are germination mats and why have I never heard of them? I start my seeds in flats, generally with 72 cells per flat, and always end up with some empty cells, even though I often put 2-3 or more smaller seeds in a cell. Is there a better way? Please do tell!
The problem with LEDs is that almost all the information that out there is nothing but pure marketing hype that should be thrown into a compost heap.
For example I'll take some of the information for Edewitts posting.
[quote]Red/blue ratio of 11:4 (165-red, 60-blue LEDs / panel)[/quote]
This is misleading because a blue LED runs at about twice the voltage of a red LED, thus at the same current they are twice as powerful.
[quote]Built-in, ballast-free, power supply circuitry[/quote]
An electronic ballast is a switching power supply just as the power supply for the LEDS should be is it is made with any quality at all.
[quote]10-years or more life-expectancy with minimum decay[/quote]
Maybe. They say with minimum decay. The problem is maybe the LED will light at x zillion hours, but what about the other circuitry. I bet a lot of them fail for the same reason that CFLs fail. Some part burns out in the power supply( ballast).
Don't take this as an attack on Edewitts he just happened to be the one that posted some concrete numbers.
Bottom line. In the real world Fluorescent lights are still the way to go.
I have been reading about metal halide lights vs. halcyon light bulbs and their advantages and disadvantages. Now i found that LEDs have been used for indoor gardening and work just as good. LED grow lights carry out in the way similar to sun like helping plants to carry out the photosynthesis that means they are grow. It always takes sunlight to aid plants generate the nourishment they require, but LEDs function as effectively even if there is no natural sunlight accessible, you will be able to connect the best type of equipment and it will do the job how the sun will perform, helping you produce healthy, mature plants.
i too was thinking of trying some LED lighting for growing my tomatoes..
in europe they use them alot..but ones they use ..from my very limited reading..and
whats out there for sale..is are you really getting the light output for the plants to grow..
my personal conclusion is that as doug9345 said.. wheres the studies..
so.. for me..im sticking with fluorescents..went and bought some new higher end
4' T8 fixtures.. i wrap the whole seedling area with mylar reflective film.. with area
in front i can open to get to plants to water..and check on..
i would love to see some actual scientific study reports on effectiveness of LED
lighting for plants..
much thanks all...
That link didn't work for me- says page not found.
I'm using T-5 high output lights with daylight bulbs, and getting good results. They are warm (not hot) to the touch and supposedly considerably less expensive to run than older fluorescents, but I haven't done the math. I just upgraded from one to 2 bulbs per shelf to eliminate drop-off in intensity toward the edges of the flats. I should add Mylar for more reflection, but haven't gotten around to it yet.
LED's seem prohibitively expensive to buy compared to what I have. I got my newest fixtures- one is 2' with 2 6400k bulbs ($85 with bulbs plus a free hanger system), and 1 is 4' with 1 6400k bulb ($55 including bulb) that I added to one I had already- from ACF Greenhouses. They were the best prices I could find on the net, and both fixtures are comparable in quality to my Hydrofarms- actually, the long one is a Hydrofarm.
The link works for me. It seems to be a Chinese website. I don't think LED lights are practical for growing plants yet. Their price needs to come down. I use 32-watt 4-foot T8 cool white fluorescent bulbs. They cost about $2.50 each when you buy them in a box of 10. I paid about $8 each for my 2-bulb fluorescent shoplights at Home Depot. That was a few years ago. I think they have about doubled in price since then, but T8 fluorescents are still a rather economical way to go.
Simply put LEDs are small light bulbs that fit easily into an electrical circuit. Not like ordinary incandescent bulbs which don't have a filament that will burn out, and they don't get especially hot. They are illuminated solely by the movement of electrons in a semiconductor material, and they last just as long as a standard transistor. I didn't catch if you were using them for a specific purpose but they are so widely available these days i.e.