JuniPerez

BLN

The last couple of winthers, I have used a 50 watt UFO (blue and red LED's) in my basement, where I have bananas, palms, agave, yucca, bamboo, chili, tomato and many more species, are they are just growing great with the LED grow lamp. It don't use much power and don't generate heat. I use the LED 14 hours every day.

I have just ordered a new grow lamp:

ProPlant6 - Hi. Power PlanteVækst diodepære 17W - 120° - Plante/Akvarie Lys - ProPlant6 - Hi. Power PlanteVækst diodepære 17W - 120°

More powerfull, and use less power.

Brian

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JuniPerez

raygrogan

I've had good luck with the el cheapo CFL's, just get a clamp lamp of some sort. Light weight, no heat to speak of.

fmu65

I got a fluorescent on discount at the local grow shop, but I also use a fluorescent fixture with "deluxe" daylight bulbs that puts off little to no heat and was really cheap. They come in a variety of sizes, even some with reflectors. Cheaper than led and my plants seem happy.

Richard

Here is the scoop on lighting.

• Lumens are a measurement of luminous flux – the amount of light perceived by the human eye. Since light bulbs were originally manufactured for human vision alone it became the standard of measure for bulbs. It is still very important in architectural design and in civil building codes. Most governments require that the lumen output of a bulb be included on the label.
• Watts are a measurement of the rate of energy transfer per second, which in science and engineering we refer to as power. Watts / square meter or Watts per square foot in the context of lighting refers to radiant flux; i.e., the amount of energy being transferred per second to a surface area.
• Example. A popular 23 Watt compact-fluorescent bulb states on the label that it has the equivalent output of a 100 Watt incandescent bulb. This means that the compact fluorescent produces the same lumen output as the incandescent. It doesn’t do this by magically creating energy out of nothing! Instead, that particular bulb is more efficient at producing radiation in wavelengths that stimulate the human eye.
• Plants absorb light from the human visible spectrum, but (depending on the plant) in ratios of about 1/3 of the blue sub-spectrum, about 1/3 of the red sub-spectrum, and about 1/3 of the rest combined. Chlorophyll – whose central atom is Magnesium, is key in this process. For most plants, it is an error to grow them with only a single wavelength of blue and a single wavelength of red. It can work, but plant vitality is reduced. It is also an error to overdose your plants the longer wavelengths of red – the so-called infrared. Plants only utilize the infrared for heat content and too much will cause stress if not overheating.
• Effective output refers to the output power of a lamp in the target spectrum. For plants, incandescent bulbs have the least effective output. An HPS or MH bulb has a nominal effective plant light output of 78%, with the lower wattage bulbs (e.g., 400W) achieving less and the highest wattage bulbs achieving near 82%. The remainder goes mostly to long-wave and heat. So for example, a 900W incandescent bulb has an effective plant light output of about 725 Watts. In contrast, fluorescent full-spectrum bulbs in the 5000 Kelvin to 6500 Kelvin range have over 90% effective plant light output, with the T5 HO 6500K bulbs near 92%. LED systems have a low effective output of 65% to 75% since they completely miss the background spectrum needed by plants.
• Diffuse light is preferred by plants as opposed to coherent light. Fluorescent bulbs output diffuse light, where as lasers are extreme examples of coherent light. Incandescent bulbs, spectrum shifters, and polarizers produce a mixture of the two.
• The equivalent of outdoor sunlight is between 50 Watts per square foot and 75 Watts per square foot of effective output – projected at a distance of 1 meter. If your bulbs are closer then less is needed, if you are farther than more is needed. The distance relationship is not linear. For example, if you half the distance you still need about 70% of the output.
• Projected area is the entire surface area illuminated by a bulb or series of bulbs. If your bulbs are uncovered (no hood) in a room 15’ x 15’ x 9’ high then the projected area is 990 square feet. If instead you have a robust mirrored hood that focuses upward and side output to the floor, then your projected area is about 225 square feet plus about 5% of the remaining 765 square feet for efficiency loss in the reflectance – a total of about 260 square feet.
• Calculate the wattage you need by multiplying the number of square feet your bulbs will project onto by the target number of Watts / square feet, and then dividing by the effective efficiency of the bulb. For example, to achieve 75 Watts / square foot in the 15’ x 15’ x 9’ example room using a reflective hood over T5 HO lamps, we’ll need: 260 s.f. x 75 W/s.f. / 92% which is about 21 kW.

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Back in business at plantsthatproduce.com

fmu65

Amazing post! Thanks for breaking it down in such an easy to understand format!

BLN

Richard, it is obvious you know a lot about light, but it's not quite up to date with the newest LED growlight. First, most of the LED lamps don't only have red an blue LED's, but also white LED's. And when we are talking LED lamps, we are not using lumens anymore, but PAR (Photosynthetically Active Radiation). One of the really good thing about LED's, are that it's alot easyer to control that the plant gets the correct wavelength they needs.

I have read alot about LED growlamps, and there are _no doubt_, that the LED's outperforms both HPS and fluorescent lamps. LED lamps are very popular here in Denmark, and I know alot of people that have replaced there HPS and fluorescent light with LED's, and they have better results with the LED's.

And another very important thing with LED's are that they use alot less of energy, and it is very important to think of climate as we are in a climate crisis.

I have today just recieved my new 17w PAR 38 LED lamp to replace my "old" 50 watt UFO. It's impressive that a much smaller lamp can be that much powerfull, it's because it's use CREE LED's (USA made), CREE LED's are the best LED at the moment.

Brian

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raygrogan

Wow, great expertise. Now, in my case I don't want the plants (taro) to grow, just stay alive and stay relatively small during the winter. (Then in the summer, outside, is when I get my growth.) The only two tricks I know are keeping the pots relatively small, so plants are root bound, and keeping the light relatively low. So what kind of lights would be not "grow lights", but "fester lights"?

timmko

I have both a T-6 unit and 400W MH bulbs. The MH bulbs are hotter and use more power but seem to do a little better. My T-6 unit has to be closer to the plants to be real effective but overall they are both great...Heres my link Hydrofarm T5 4FT Designer Fluorescent Grow Lights - Plantlighting Hydroponics & Grow Lights

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nannerfunboi

much thanks to all on experiences .. i am looking into the
LED grow lights too i know the europeans are way ahead of us
here in the states in lighting tech..ive checked out whats on ebay..
and there alot of low priced lights ..then the much higher end..
for me..i too just want to have the minimum lighting on overwintering
my tropicals..
i am interested in knowing the sucess of using LED's on seedlings..???
anyone???
great to have some dialog on this here!!!
thanks all

sunfish

The Hollyberry Lady

Richard

I'm aware of all this. If you want to do a comparison, compute the power spectral density of any commercial LED system in the response spectra of plants and compare it to a 6500 Kelvin fluorescent.

Less power in means less power out.

But to be fair, first compute how much wattage you need in effective output and then go out and find a system to meet it. Globally, the cost of choices varies.

10 Watts per square foot of projected area.

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BLN

You can just buy a smaller LED lamp, a 12w lamp are today pretty cheap, and then increase the distant between the lamp and your plants.

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BLN

Yes, i make almost all my tropical plants from seeds, and at winter the only "sun" my seedlings gets, are from the LED growlamp. At february/march I also makes chili, peper and tomato seedlings.

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Richard

Plants absorb light from the human visible spectrum, but (depending on the plant) in ratios of about 1/3 of the blue sub-spectrum, about 1/3 of the red sub-spectrum, and about 1/3 of the rest combined.

LED does not provide this. The LED's used in "plant" light fixtures are manufactured for telecommunication fibers. The bandwidth of each color is purposely very narrow.

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the flying dutchman

I guess Richard is right. I used the unscientific approach and checked
wich growlights are sold in Cannabis growshops in Holland. They all sell
400 and 600 watt bulbs, no LED lights. In my opinion they would be the
first to use led lights because they have enormous problems with all the
heath that the bulbs produce. The heath is easily detected by the police
who use infrared cameras in helicopters and if it snows the snow melts
from the roofs where they grow the Cannabis so that is suspicious too.
I do know however that some commercial crop growers are experimenting
with the LED lights, maybe they use a combination of Bulbs and LED's, if that makes sense?

Ron

stevelau1911

I've tried getting the 90 watt UFO light, but it was very noisy with it's fan and eventually half the leds burnt out within a few days so I had to return it. I did find that the vegetative growth during that time on my plants seemed pretty solid especially for comparatively weak light. If you do get one, I would suggest going with the generation v type Blue Red 225 SMD LED Grow Light Panel 30w Indoor Garden Hydroponic Plant Lamp | eBay

It would suck to have a fan burn out or the lights stop working all of a sudden due to overheating, but from a week of using leds, I believe that a 90 watt led is by far more useful than a 70watt consuming cfl. Of course it's performance may be inferior to that of a true 400 watt metal halide, hps or any other commercial greenhouse light but I believe leds are pretty useful as long as you don't get the 9 watt consuming cheap stuff which is hardly sufficient for a night light.

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I'm in zone 6 upstate NY, specialize in growing temperate cold hardy bamboos(mainly phyllostachys) and starting to get into bananas.

my picture website is http://www.flickr.com/photos/31489820@N02/

http://stevespeonygarden.blogspot.com/

JuniPerez