Has anyone tried LED grow lights for seedlings?

tomatoguy · February 15, 2008

I see these blue and red LED systems advertised as grow lights a lot lately. I can see the advantages; less power consumption, less heat, etc. I wonder, though, if the spectrum would be good for tomato seedlings and if they are as powerful as they are advertised to be. Does anyone have personal experience with these?

I already have a two-tiered system of fluorescent grow-bulbs and Metal Halide light so I'm not looking for advice on getting started. Just looking for alternatives. In other words, I have an extra shelf in my grow box that doesn't have lights.....yet.

mater

dcarch · February 15, 2008

LED for planting, very interesting topic. I have not yet used LED fixtures for growing.

I am not going to discuss one major issue with LEDs: LEDs are monochromatic, (single color). You have very limited colors to use. So whether it’s good or bad to use single narrow spectrum for growing plants is for someone else's discussion.

LEDs have many other limitations:

Low voltage direct current driven. You cannot plug LEDs directly in 110v outlets. You need to step down and rectify to mostly 3 to 6 volts DC. LEDs will instantly burn out if you exceed the voltage and current specs. LEDs sold as grow lights most likely are not operated by solid-state driver/power regulators. Possibly they are run in series like Christmas lights, so if one burns out the whole string may get burn out. LEDs do last about 100,000 hours, however.
Heat sensitive: high power LEDs generate a lot of heat, and they require heat sinks or other ways to get rid of the heat, or they will be fried.
Focusing. 5mm type of LEDs are pre-focused with narrow beam lenses, so light distribution is a problem.
Luxeon, Cree, Rebel, K2 type of high power LEDs require individual custom lenses or reflectors, making it impractical for plant light fixture design.

I believe LEDs will be practical for plant growing sometime in the near future. They are still very expensive and not too efficient, but advances are being made rapidly.

dcarch

OmahaJB · February 16, 2008

Great topic, as I had considered buying some LED lights a few months ago. I stumbled onto a website that was selling LED lights, and was intrigued. But I wasn't about to sink a couple hundred dollars into something I didn't know enough about. If I were going to do that I'd just put money into a switchable MH/HPS HID system. Which is something I'd like to have when I can afford one.

Thanks for starting the thread 'tomatoguy', and for the breakdown on LED's 'dcarch'. I'm sure others here will appreciate the info as well.

Jeff

February 15, 2008	#1
tomatoguy Tomatovillian™ Join Date: Jul 2006 Location: Rockvale, TN Zone 7A Posts: 526	Has anyone tried LED grow lights for seedlings? I see these blue and red LED systems advertised as grow lights a lot lately. I can see the advantages; less power consumption, less heat, etc. I wonder, though, if the spectrum would be good for tomato seedlings and if they are as powerful as they are advertised to be. Does anyone have personal experience with these? I already have a two-tiered system of fluorescent grow-bulbs and Metal Halide light so I'm not looking for advice on getting started. Just looking for alternatives. In other words, I have an extra shelf in my grow box that doesn't have lights.....yet. mater

February 15, 2008	#2
dcarch Tomatovillian™ Join Date: Jun 2006 Location: NY Posts: 2,618	LED for planting, very interesting topic. I have not yet used LED fixtures for growing. I am not going to discuss one major issue with LEDs: LEDs are monochromatic, (single color). You have very limited colors to use. So whether it’s good or bad to use single narrow spectrum for growing plants is for someone else's discussion. LEDs have many other limitations: Low voltage direct current driven. You cannot plug LEDs directly in 110v outlets. You need to step down and rectify to mostly 3 to 6 volts DC. LEDs will instantly burn out if you exceed the voltage and current specs. LEDs sold as grow lights most likely are not operated by solid-state driver/power regulators. Possibly they are run in series like Christmas lights, so if one burns out the whole string may get burn out. LEDs do last about 100,000 hours, however. Heat sensitive: high power LEDs generate a lot of heat, and they require heat sinks or other ways to get rid of the heat, or they will be fried. Focusing. 5mm type of LEDs are pre-focused with narrow beam lenses, so light distribution is a problem. Luxeon, Cree, Rebel, K2 type of high power LEDs require individual custom lenses or reflectors, making it impractical for plant light fixture design. I believe LEDs will be practical for plant growing sometime in the near future. They are still very expensive and not too efficient, but advances are being made rapidly. dcarch __________________ tomatomatomatomatomatomatomatomatomatomatomatomato matomato tomatomatomatomatomatomatomatomatomatomatomatomato matomato tomatomatomatomatomatomatomatomatomatomatomatomato matomato

February 16, 2008	#3
OmahaJB Tomatovillian™ Join Date: Feb 2006 Location: Toledo, OH Posts: 1,821	Has anyone tried LED grow lights for seedlings? Great topic, as I had considered buying some LED lights a few months ago. I stumbled onto a website that was selling LED lights, and was intrigued. But I wasn't about to sink a couple hundred dollars into something I didn't know enough about. If I were going to do that I'd just put money into a switchable MH/HPS HID system. Which is something I'd like to have when I can afford one. Thanks for starting the thread 'tomatoguy', and for the breakdown on LED's 'dcarch'. I'm sure others here will appreciate the info as well. Jeff