LED grow lights

[greg_s]

Does anyone have any experience with growing under LED plant lights?
I ordered one as an experiment and it should be delivered next week. Either way I will make sure that I post about my progress.

Thanks,

Greg

[mayres]

Hi Greg - this subject has come up a number of times in the past year. Lots of curious folks, but no serious users. If you have a way to measure the foot candles delivered to your orchid(s) please post when you get set up. mike

[pikespeak62]

I'm very interested in your results.
Have tried, on numerous forums, to find someone growing under LEDS
I really want to use them instead of my HID setup.

[greg_s]

Glad to see that I am not the only one curious about it. I am expecing the light on Monday. I only got a single bulb to start with to try it out. It is a 66 LED bulb with a red/blue mix.

Mike, I have a light meter that measures in lux but I think we can convert it to footcandles

Pikespeak, I know what you mean. I have been trying to find some real information on it too. I figured I'd just have to come up with some data on my own.

In any case, I will keep you guys appraised as to my progress.

Thanks,

Greg

[greg_s]

Light was delivered today. I measured the light output at the recomended distance of 16 inches as 3300 lux. If I am doing the math right that puts it in at about 306.5 footcandles. This seems low but from what I understand of the lights and growing technique that is normal. The trick is that this is supposed to deliver only wavelengths of light best suited for photosynthesis (the reds and blues).

Since this is reading so low I am going to start off using the bulb to suplement orchids that I have growing in one of my darker windows. I will start off with the light 36 inches from the plant and slowly move it closer.

If the plant reacts well, I will try using the bulb as more of a primary light source.

[mayres]

If you only have 306.5 footcandles I don't think (?) you will not get vary far with orchids. My experience is that you need to get as close to 1000 as you can for LOW light needs orchids. Keep us informed.......

[greg_s]

I felt the same way but I have been doing some research and I think the theory behind it goes: you need 1000 footcandles of white or full spectrum light to get enough of the reds and blues that it uses. This thing claims to deliver just those reds and blues that would be contained in the proper amount of white light.

I may be incorrect with this...but this is what I have been putting together from my reading.

[mayres]

Sounds interesting - we will continue to learn about this together.........
I guess the bottom line will be how your plants respond. Ideally you would have a group of identical plants - some under this unit and another under 1000 footcandles of full spectrum light and see how they do. I have done a fair amount of reading as well and have noted that cheapie cool fluorescent tubes do as well or better than full spectrum - primarily delivering the blue end. My setup has some of each. Onward we go! mike

[PhalPal]

Greg - can you get your plants closer to the light?

[greg_s]

Mike, this is absolutely a learn as we go thing. Thanks for your feedback and if you find anything in your studies that might be of interest or conflicts with what I have found, by all means let me know.

PhalPal, I could but I am trying to avoid 2 things:
1) something that is being nicknamed "LED shock".

In summary, it is the plant reacting poorly to too much of a good thing. I have read where people compare it to over fertilizing. Kind of the 'too much of a good thing' idea. I can avoid this (apparently) by introducing the LED light slowly (aka from a distance).

2) deformations in the leaves and/or flowers.

The light does not get hot, just warm (slightly higher than room temperature to the touch) so the plant can grow right up to and against the lighting surface. The down side to that is that people have documented that the plant (while still healthy) will show deformations like curling or spiraling in the leaves and flowers. I can avoid this (apparently) by keeping the plant 12 to 16 inches from the light.

Again, this is all going to be a learning experience so we are just going to have to see what really happens.

Thanks,

Greg

[greg_s]

Just as a follow up to this post:

The LED lighting is working out great. I tried this light out on a reed stem epi that was in a north window (~200 footcandles of natural light and ~300 footcandles of LED light). It has been progressing nicely with new growth and plump strong stalks. Because of the success I have had with this small "supplemental" light, I figured I would convert one shelf of my basement grow stand to be purely LED. I am running though the final setup now and should be able to start growing with 100% LED light soon. I will continue to update this thread as I go.

Thanks,

Greg

[robb]

greg: sounds like it is working! i too was quite skeptical as to the efficacy of LED's, as they have such a low light output. as you mentioned, the plants will utilize the red and blue light best, so maybe it does work quite well, delivering only what the plants require. your further experiment, converting an entire bench to LED, should firmly establish whether this is a suitable light source. if you don't mind my asking, what did the light cost? where did you purchase it? any special wiring for it?

[mayres]

How about some other details that people would find interesting too - wattage, price of bulb, how many square feet of lighting do you figure it will adequately light up, etc. Are you going to set up a bank of 8-10 of these?

[greg_s]

Sorry if I was a little vague. Here are some specifics:

The bulb I have been using cost me ~$30.00. It is 5 Watts, 60/110 VOLTS, and contains 66 LEDs (12 blue, 54 red). I have been keeping it ~16" from the top leaves and it covers enough growing area for one 6"-8" pot.

I think I am going to use something slightly different for my basement grow stand. For the sake of time and money I think I am going to go with 3 LED pannels. These pannels cost ~$80.00 and have 228 LEDs each in a 20%/80% blue/red mix. They are 16 Watts /120 volts, and measure 12.25" wide x 1.25" deep. These might be overkill for my grow stand because the distance from the lights will be relatively short (only ~36" from the pannel to the shelf when they are rated for 64" to 92"). However, in doing some research and talking with the supplier I don't think this is going to be too much of a problem, at least at first. I am going to be doing my initial testing with normally high light orchids (like the reed stem epi I used with the single bulb) so I don't think they are going to mind the extra light since there is no heat and no green/yellow wavelengths. But, as I said before, this is all a learning process. When I switch over to testing lower light orchids I may need to adjust my distances so that I don't stress them.

In as far as changes to the grow stand: I had to add new legs to the stand extending the distance to the top shelf (the affore mentioned 36"). The only wiring change I needed to make was to include a surge protector in my setup. Right now I have a mechanical timer that leads to 2 outlets (one on each shelf). The surge protector runs from the outlet and the LEDs will run from that. (This leaves me the option to run another light or another surge protector later.)

Any questions or suggestions are always welcome!

Thanks,

Greg

[mayres]

When you get everything set up the way you want take a pic and post on this thread - all of us non-greenhouse and non-tropical environment type folks are always interested in seeing the creative ways that orchids can be grown indoors. Looks like if you wanted to grow 100 orchids or so you would have to have a significant "bank" of these?
Good luck to you! mike

[jay]

This is amazing. I had not heard/thought of this before. I am really looking forward to seeing the results of these lights as a primary light source.

Greg, maybe I missed it, but I didn't see where you are buying these from. Is it online somewhere?


Jay

[Fabolusus]

I was thinking about using LEDs as a supplement to my HID setup. My main light is a 400 watt eye-hortilux BLUE metal halide, and I think that my babies would benefit from a light in the high red spectrum. Please let us all know how it goes!