LED Grow Light Opinions

[Steve F]

I'm new to hydroponics. I built three small Aeroponic units and am working on a drip system. Seeing how my garden is in my home office, I started experimenting with LED lighting. I'm using Red and Blue lights I scrounged from ebay, govt surplus, etc. They seem to be working great! I have three 2 foot tall Tiny Tim plants with many small tomatoes now. I have lots of Bell pepper flowers (no fruits yet but close). I also just started a cucumber patch a few days ago and have sprouts about three inches tall.

LED = low power use (to light all the above 8 square feet uses about 120 watts and nice to the eyes and no heat.)

I was just wondering if anyone else has any experience with LED lighting good or bad and wants to share experiences and experiments with me. I have many pictures but do not know how to post them here.

There are a few LED Grow light sellers out there, but very expensive. The lights I've put together are way cheaper than buying conventional MH or HPS

Opinions/Experience appreciated

Thanks,
Steve

[Steve F]

I've added some pictures of this to http://www.greenpinelane.com

Steve

Neat looking setup... what did you exactly put together? ie. did you buy LED's and solder stuff together, or whole sets of blue and red leds in a bulb type pre-made layout?

[NJGardener]

I purchased the commerial ($150) three (group) LED light last year as an experiment to see if it would provide enough "active" light to help an "outside" plant survive inside over the winter. I kept the plant near a window and used the light as a supplement. My results are mixed. The plant survived and maintained flowers, but I don't know if the LED's helped a lot, some or none.
I'm experimenting with an AeroGarden currently and may add the LED bar to the side to see if I can see any difference. The lights in the AeroGarden are so bright that I think they are providing all the light needed however. Your site is interesting and I'd like to see you post your experiences here more frequently.

[Life Light]

Hi all,

Time to lay to rest another myth.

You can only create light that plants can use, PAR light, AKA the visible spectrum, when the light has plasma. The Sun makes plasma, HID lights make plasma, and that's about it. Other lights like LED's and fluorescents make light differently, and they basically are just glowing and burning phosphors, in essence.

No plasma means no effective light that can have any power, amplitude or proper spectrum that plants need to make photosynthesis. If the light can't penetrate, its ineffective for overall plant growth. LED's deliver light to a linear plane, and can't penetrate.

You can all research this from this basic bit of science and photobiology.

Cheers

[NJGardener]

I thought that light energy is delivered a photons so regardless of the source, if photons of sufficient quality and quantity are reaching the plant leaves they effect growth. I'm not following the plasma issue. If as you say, fluorescent and incandescent (and I presume LED) lights are not generating "plasma" how do they contribute to the growth that we see when these are used as "sole source" lighting?
Modern high output LEDs are pretty darn bright. The question I see is just how bright are they effectively in the PAR spectrum? It's difficult for us to do a direct comparision so about the only thing we have to work with is the apparent effect on growth. Right now, one seems to need a LOT of LEDs and very close to the plant.

[Life Light]

Plasma consists of a collection of free moving electrons and ions - atoms that have lost electrons. Energy is needed to strip electrons from atoms to make plasma. The energy can be of various origins: thermal, electrical, or light (ultraviolet light or intense visible light from a laser). With insufficient sustaining power, plasmas recombine into neutral gas. Plasma can be accelerated and steered by electric and magnetic fields, which allows it to be controlled and applied.

The results you see from the plants under LED's is just the plant making the best of what you're giving them. Plants are the most adaptable living things on the planet.

You can make an LED bright to the human eye, but to the plant it doesnt have the energy that it needs to make PAR light. PAR light again, is visible light, the visible spectrum.

LED's have no amplitude, and can't penetrate beyond a linear plane. Weak light for weak results.

[Steve F]

Whether they are adapting or not, I'm starting to see pretty good results from 100% LED lighting. What's real exciting is I have full size sweet pepper plants fruit setting and some peppers near ripe, all 100% LED grown (not even any Sun through a window). I don't agree that PLASMA has anything to do with it. PLASMA reaction is a great light source of course. However, it's the photon density that counts at the correct spectrum, not the physics of the source of the photons. I also disagree with saying 'the visible light spectrum' must be reproduced. Although the NM ranges I am using for grow and bloom are 'visible', there is no need of reproducing the entire visible spectrum (especially green and yellow). The photos and documentation of what I am doing are at www.greenpinelane.com. It is definately not 'finished' by any means, but good growth is happening so far. I'm also not claiming that they are better than other lighting. I'm just saying LEDs work, they are cheap (the ones I use anyway), and they are LOW on watts usage. Check out my site to see photos of what I'm saying...

[Life Light]

All life has evolved to use the visible spectrum, the light that hits the earth. I think we can all agree to that. We can't cherrypick the spectrum and say plants don't need green or yellow light, which they use. Plants do use green light, most of the time to make photosynthesis, to fire the pigments in the light harvesting complexes. I recommend reading a book called Photosynthesis by Hall and Rao, 6th edition. It's the book on photobiology, and shows current research.

Plants are very adaptive, and I'm sure they are adapting to your LED lighting. But what I said in my first post here stands true. It's science and physics. You have to have light with spectrum and amplitude, and be able to deliver that light. If i stand on a ladder, the sun is just as powerful as if i lay on the ground. That's amplitude of light. We can't replicate that indoors with LED's and lights that simply "glow". I realize that the idea of LED's are a novelty for plant growth, but let's be green with the energy that we are producing and get the most for our energy dollars.

[Steve F]

I don't want to seem like this is an argument, but I guess I really don't know what you are leading to here. I know the real sun can never be reproduced indoors. All artificial lighting systems have basically the same penetration problem as light power decreases by the distance squared.

I think I have some decent growth at 3 watts per Cucumber plant right now with one Blue 3 watt light I'm testing on a couple of them. I keep the light real close to the leaves to address that amplitude problem or actually photon density you refer too. If I have to add a couple more 3 watts or so as it gets larger...so be it...

So, how does your statement of using the least power available to keep it green apply to LEDs and not other high power systems like HID or others like Fluorescents? None of these lights would pass the climb the ladder test either.

If I can someday grow a plant using let's say 10 watts instead of say 50watts, wouldn't that be a good thing?

Or are you saying that because my plants are adapting to different light (like not having green) that this is bad too because it's different than the sun? I've read lots of books that say green is not used. The number of biological study end-results is like flipping a coin. Keep reading articles until you find one that agrees with your view. This is why I'm actually trying it and not just talking and reading about it. All indoor lights are different than the sun...I think.

I know it's early in the LED technology stage for them to replace conventional grow lighting, especially in large growing and commercial situations. For smalltime hobbyists like myself, I believe it is feasible for a few plants and I'm trying to see if what I believe is so, not just reading about other people saying it isn't.

Also there's a little environmental side note to LEDs. They don't pollute the earth with heavy metals and other chemicals like the millions of other bulbs we are disposing of everyday. I think LEDs are a step in the 'keeping it green' direction.

Or are you simply saying that overall growing inside with any lights whatsoever is a bad thing and we should only use the sun? If this is the case, then I cannot grow plants in the early spring, late fall or winter at all as I live up North where the sun isn't strong enough to get the temperature above freezing because of the earth's tilt and distance, etc, etc....