Anyone using LED grow light?

[daniella3d]

Hi, I am sure this has been asked before but the search result does not give me anything for LED grow light so...

Does anyone here use these LED grow light? how many hours per day? and what is the watt and distance from the plant you are using?

Currently I have a 180W UFO grow light for my Philippinenses and my Sanderianum, about 14" distance, 12 hours per day (hours of light at their natural location in Borneo year around). This past winter I did not have any paph and I used this ligth for my nepenthes and they did extremely well under this light. My mirabilis became all red, produced lots of pitches and did one flower spike. So I was not too afraid to use it for my paphs.

Should I increase the duration to get my plant to flower? for now the foliage is a medium to light shade of green, not dark green. What is your own experience with this type of light?

 

[naoki]

I use several kinds of LEDs, and I place my 90W 5-band UFO (which is actually around 67W consumption) further than 14" (I think around 2' to the top of the leaves). But the beam angles are different from one model to another (mine has really narrow angle, so small coverage). Also the variation in efficiency among models are dramatically different (mine is an older generation which uses so-called 1W diodes, I believe). So it's not easy to say what is the good distance for your model.

I just went to measure the intensity of my 90W UFO. At 12", mine is giving about 1/4 of the full sun (a bit technical, but the photosynthetically active radiation, PAR, of 550 micromole/m^2/s). If you double the distance, the intensity goes down by 1/4, so at 2', I'm giving about 140 micromole/m^2/s, which is pretty good for Paphs. This is equivalent to 700 foot-candle (fc) of sun light. It seems to be lower than what is recommended, but the recommendation is usually for the peak intensity (i.e. at noon of natural light). With the continuous light of 700 fc, you are giving similar cumulative amount as 1000-1400 fc PEAK light under greenhouse.

Without PAR meter, it is difficult to know the appropriate distance. But if they are growing well without leaf burn, it is probably good. I personally would start from further away, and then gradually make it closer.

How many sqft of area is your 180W covering now? I would guess the height which will cover about 3x3' is probably good for Paphs. I'm assuming that your 180W model is about 120W actual consumption, which can cover about 12 sqft or less (for Paph type light). 10W per sqft. could be a bit low end even for Paph (here I'm talking about the actual watt, and what is advertised with LED is usually NOT the actual energy consumption).

I use 13-14h/day.

 

[TyroneGenade]

Ray, of www.firstrays.com, sells a nice screw in LED that seems to work well.

Regarding PAR readings you can take a good guess using a Lux meter providing you are using a cool, natural or warm white LED. On average you get about 0.013 PAR/lumen. If you have blackberry or the like, you can download a luxmeter app and get a reasonably measure of the lux. Using the 0.013 conversion factor you can guestimate the PPFD (photosynthetic flux density: microE/m2/2).

 

[daniella3d]

thanks for the info!

I am using a 180 watt 8 bands model based on 3 watt diodes. The lens are 120 degree so they spread wider and less concentrate than a usual 60 degree lens.

I just bought a light meter and should receive it in few weeks but I was wondering if the measurement from these meters is right when measuring such narrow bandwidth of light. It will measure in lux or foot candle, but not in PAR.

Glad to know that your 1 watt based model does well at 2 feet height. Meaning probably I should rise my light to 2 feet instead of the 18" I am using. My terrarium is 3' x 2' and for now only half the LED are working because one of the two controller need to be replaced. I guess once I replace it and all the LED are working I will have to rise the lamp for sure. The foliage is getting lighter not darker.

I use several kinds of LEDs, and I place my 90W 5-band UFO (which is actually around 67W consumption) further than 14" (I think around 2' to the top of the leaves). But the beam angles are different from one model to another (mine has really narrow angle, so small coverage). Also the variation in efficiency among models are dramatically different (mine is an older generation which uses so-called 1W diodes, I believe). So it's not easy to say what is the good distance for your model.

I just went to measure the intensity of my 90W UFO. At 12", mine is giving about 1/4 of the full sun (a bit technical, but the photosynthetically active radiation, PAR, of 550 micromole/m^2/s). If you double the distance, the intensity goes down by 1/4, so at 2', I'm giving about 140 micromole/m^2/s, which is pretty good for Paphs. This is equivalent to 700 foot-candle (fc) of sun light. It seems to be lower than what is recommended, but the recommendation is usually for the peak intensity (i.e. at noon of natural light). With the continuous light of 700 fc, you are giving similar cumulative amount as 1000-1400 fc PEAK light under greenhouse.

Without PAR meter, it is difficult to know the appropriate distance. But if they are growing well without leaf burn, it is probably good. I personally would start from further away, and then gradually make it closer.

How many sqft of area is your 180W covering now? I would guess the height which will cover about 3x3' is probably good for Paphs. I'm assuming that your 180W model is about 120W actual consumption, which can cover about 12 sqft or less (for Paph type light). 10W per sqft. could be a bit low end even for Paph (here I'm talking about the actual watt, and what is advertised with LED is usually NOT the actual energy consumption).

I use 13-14h/day.

 

[daniella3d]

I need to buy another of these lights for my new phrag, so that they have more light in winter. I want a 3w based led light with 8 or 8 bands, not something white. I don't ming a purple light if it's better for the plants.

I have an Iphone, so not sure this application is available but I will check it out. thanks a lot!

Rick, of www.firstrays.com, sells a nice screw in LED that seems to work well.

Regarding PAR readings you can take a good guess using a Lux meter providing you are using a cool, natural or warm white LED. On average you get about 0.013 PAR/lumen. If you have blackberry or the like, you can download a luxmeter app and get a reasonably measure of the lux. Using the 0.013 conversion factor you can guestimate the PPFD (photosynthetic flux density: microE/m2/2).

 

[Silvan]

I have a few of these : http://www.ebay.ca/itm/140W-LED-Gro...?pt=US_Hydroponics&hash=item19e9ff1638&_uhb=1

I call it the fake 240 watts since it's 80 x 3watts led, but depending on the colour it never uses the full 3watts capacity of the led...

I really love it. I keep my plants at a minimum of 3 feet under the fixture and
it's quite enough. I've been playing with length of time and I find that it's
the same as if you would grow under normal fluos (12-15hours).

 

[Silvan]

But it's a real pain for the eyes...

 

[Silvan]

My kovachii 'Jewel' last december before going under Led (Used to be grown 2feet under a fixture of 4x4f. T5HO 6500k) :

same plant picture taken today :

I'm all about results!

 

[TyroneGenade]

Hello,

I agree, those lights look ugly.

If you know the exact band widths of the 8 band lights you can go visit http://www.1023world.net/diy/spectra/ It will give you the uE/m2/s and Lux values for each LED. If you know the number of LEDs and the ratio of the different band widths you can work out an average Lux:uE/m2/s ratio you can use to work out what your uE/m2/s is based on a Lux reading.

If you are getting a quantum meter then you are going to measure in uE/m2/s in any case but the Lux meters are measuring of a spectrum from 400 to 700 nm but it peaks between 500 and 600 nm. The Lux values on the website take into account the relative effectiveness of the lights of 400-500 and 600-700 nm at registering on the lux meter.

 

[Silvan]

Thanks Tyrone, that's a very useful link!

I also have one of these : http://www.ebay.ca/itm/98bulbs-3W-c...LH_DefaultDomain_0&hash=item1e817b3431&_uhb=1

it's less agressive for the eyes. But I've only been growing under this one for about three months so I can't say if my plants likes it or not. If you scroll down on the page it gives you the wavelength and power consumption for each color and
some very interesting infos.

 

[Erythrone]

Silvan, your Kovachii is spiking???

 

[Silvan]

For my seedlings of phragmipediums I use this one :

http://www.ebay.ca/itm/Grow-LED-Lig...?pt=US_Hydroponics&hash=item3a7d1ef81c&_uhb=1

Right now I'm only using half of it's strength.

nice colour of leaf :

...man, this post is making me realize that I have a lot of plants.. :rollhappy:

 

[Silvan]

Silvan, your Kovachii is spiking???

Yup. Two of my kovachiis are spiking. 'Jewel' and 'Laura x Ana'.
One growing under led in rock wool/diatomite and the second one
under T5HO in a bark mix..

 

[daniella3d]

This light is quite blue, so it will favor the growth but not flowering?

I use to have a reef aquarium and this is the type of LED light to use for corals, a lot of blue.

Why did you choose that one instead of those with more red?

I like the 150 watt light in your link. I might get that one.

I don't really care about the color output, and I don't mind looking at my plants in purple. I want the best for the plants.

Thanks Tyrone, that's a very useful link!

I also have one of these : http://www.ebay.ca/itm/98bulbs-3W-c...LH_DefaultDomain_0&hash=item1e817b3431&_uhb=1

it's less agressive for the eyes. But I've only been growing under this one for about three months so I can't say if my plants likes it or not. If you scroll down on the page it gives you the wavelength and power consumption for each color and
some very interesting infos.

 

[Silvan]

the shipping cost for the one from the states was (is) verrrry expensive and it doesn't take in account that you'll have to pay for customs (about 25$ CAD).
But it's a good light.

I bought the one for aquarium because it had more blue and white as the leds usually have a lot of reds (3:1) and I wanted to try something with the reverse ratio because I wanted a more luscious foliage And when I started using led I burned a lot of plants with the ones that had more red in them (and more wattage).
Now that I figured out the distance I don't have that problem anymore.
You can flower some phragmipediums under cool whites (T12/T8). They don't all need intense lights. Under this fixture I have a lindleyanum in bloom, angreacum lemforde. There's also a longifolium, mem. Jack Stoddart, Hanne Popow,
Jerry Lee Fischer and Hanne Popow x Lutz Rollke that are spiking. I think it's more about the quality of light than the intensity when using Led lights.

 

[Bjorn]

Yup. Two of my kovachiis are spiking. 'Jewel' and 'Laura x Ana'.
One growing under led in rock wool/diatomite and the second one
under T5HO in a bark mix..

I am highly impressed, what about temperatures?

 

[naoki]

That seems to be a really quick recovery of P. kovachii! It looks like a pretty compact clone?

Daniella, if you are a little bit handy, Cree CXA-3070 is a great deal (cheap initial cost, high efficiency, easy to DIY). It uses newer COB (chip-on-board) technology. I'm not sure what you mean by best, but if you mean the most growth (most PAR) per given electricity cost, Build My LED is pretty high up there (fairly expensive initial cost, though). This paper has tested several LED fixtures, and BML stuff is near the top. I don't know how well CXA-3070 compares to these top-dogs, but from my testing against cheaper ebay COB LEDs, I was pretty impressed.

Silvan's 140W is probably the one made by a big chinese maker, Bysen (I think it's Helios Series). I think a few of diodes (not all) are Cree. It looks like that it has nice homogeneous light spread, and it's looking pretty nice!

With regard to the half-broken UFO, it could be caused by only a few open-circuited diodes (instead of the driver). Since many of diodes are serially connected, if one diode breaks open, quite a few diodes don't light up. I have cheap LED fixtures, which I have to keep replacing the diodes every couple months.

With red vs blue spectrum for flowering vs vegetative growth, it is too much of generalization. It is true for some plants whose flowering is determined by day/night length (photo-periodic plants), there isn't much evidence for red vs blue influencing the flowering of most orchids. I agree with Silvan that orchids will flower under blue-ish light.

The other more general effect of light spectrum is the shape of plants. I personally think that the reef-type LEDs may not be most efficient for orchids (but I may wrong because blue LED is usually more efficient in terms of producing photons per watt than red ones). But it may make the plant to be more compact. This effect seems to be fairly common in plants, but orchids may respond differently (I haven't seen any experiments to test the effect of blue light, cryptochrome-related photomorphogenesis, in orchids). Silvan, do you happen to notice that orchids under the reef light is more compact than the red dominated light?

 

[Linus_Cello]

wow, such blue light... where's the tridacna?

 

[daniella3d]

So where do you buy your led kit? I would not mind building my own kit if it was more affordable that way. What I meant by what's best for the plants is I want the best light spectrum for the plant growth, never mind how it look to my eyes, I don't care about that.

Some people go with the white light because they can't stand the purple color, but it's not as efficient for the plants. I may be wrong but I think my sanderianum might grow faster under a light that provide lots of photosynthesis instead of a light that provide just half of it or so. This plant is such slow growing that I want to do what ever I can to help it get there faster and better. So far my Philippinense are growing like mad under the LED.

As for my light that has half of its light out, it's the controller for sure, because each half is controller by its own controller and I tested it and the half that is out will light up if I exchange the bad controller with the good one. These little controller are 8$ free shipping, so not so bad to repair. I have that led light for a little more than a year.

I am looking forward to hear about what will happen with the plants under the blue light. It works great for corals, never tought about using it for plants but....I know that with a reef aquarium growing under a blue light discourage the algae growth, whereas using a red light can create a real problem with algae but many people still use some red light because they also have marine aquatic plants. Those plants usually grow much better with the red light and not so much with the blue. Just a thought.

With regard to the half-broken UFO, it could be caused by only a few open-circuited diodes (instead of the driver). Since many of diodes are serially connected, if one diode breaks open, quite a few diodes don't light up. I have cheap LED fixtures, which I have to keep replacing the diodes every couple months.

With red vs blue spectrum for flowering vs vegetative growth, it is too much of generalization. It is true for some plants whose flowering is determined by day/night length (photo-periodic plants), there isn't much evidence for red vs blue influencing the flowering of most orchids. I agree with Silvan that orchids will flower under blue-ish light.

The other more general effect of light spectrum is the shape of plants. I personally think that the reef-type LEDs may not be most efficient for orchids (but I may wrong because blue LED is usually more efficient in terms of producing photons per watt than red ones). But it may make the plant to be more compact. This effect seems to be fairly common in plants, but orchids may respond differently (I haven't seen any experiments to test the effect of blue light, cryptochrome-related photomorphogenesis, in orchids). Silvan, do you happen to notice that orchids under the reef light is more compact than the red dominated light?

 

[Erythrone]

Yup. Two of my kovachiis are spiking. 'Jewel' and 'Laura x Ana'.
One growing under led in rock wool/diatomite and the second one
under T5HO in a bark mix..

I just realize you were writing about PK hybridisation for this reason...
oke:oke: As we say here "Pas vite, la fille"