Growing with LED's

Before you buy them--assuming you haven't already--try and find out what the wavelengths / emission spectra are for those lights. Wavelength is all-important; lights with the "wrong" wavelengths will be virtually useless for growing marijuana. Since the lights are warm white I would expect some of mj's red action spectrum to be covered, but blue is also important. Marijuana has a few "sweet spots", namely 440nm (blue) and 670nm (warm red). Unforunately, LED lights usually fall somewhere in between these sweet spots where the light is basically useless for plant growth. I've also done some LED window shopping and I would recommend you either buy LED grow lights or, better yet, stick to fluoros.

Here's a chart to help you out.

 

I would stay away from that light because you don't know enough about it. As Runner said, there are LED grow lights that can be very effective, but I wouldn't get an LED without knowing specifically how it meets MJ's spectrum requirements.

 

wow... the buzz on LED growlights is overtaking ceramic metal halides which are STILL impossible to find despite being around 4-5 years.

it's just too bad that LED systems are so crazy expensive. it occured to me that LEDs are so efficient when you can see so much better with LED flashlights thatr last much longer with smaller batteries so i tried "led growlights" tonight and got real excited unti i started getting an idea on pricing. i can see why the dealers aren't listing light requirements for the equivilent of 400w etc.

it looks like DIY is the best bet for now, until the chinese catch on anyways. all an LED array is is a bunch of bulbs, resistors and a power supply.

 

ceramic MH? what's the difference from a standard MH?

 

Check out this thread http://forum.grasscity.com/general-indoor-growing/93801-led-lights-pics.html
It may or may not help answer some of your questions. Although, when it comes to growing w/LED's there is a lot we do not know.

 

This is an interesting topic. I agree that LED grow lights are the future.

We need to find a lower cost product that suits MJs specific requirements.

Runner mentions two sweet spots "namely 440nm (blue) and 670nm (warm red). "

Where did these values come from. I see the chart above and read Horticulture books this is a standard curve for almost all plants.

is anybody aware of other sweetspots for MJ. ie far red or UV. What about green and yello light?

Also what ratio of Blue to red light is needed is it 50 50 or ?

 

to your inquiry of green and yellow light, the spec is actually more like 430nM and 660nM. ever notice that plants are green and yellowish in some stages. this is caused by clorophil. the world has been evovlving for eons, so life has developed to use the environment to its suiting. therefore the light spectrums that plants use directly coincides with their host setting. it isnt that they dont use that spectrum (yellow/green) its because they reflect it out in the process of obtaining their usable spectrum, the very reason that plants are green (clorophil) is the reason it is filtered out. essentially its no surprise that green falls right in the center of the spectrum allowing plants to use red and blue to the fullest of its extent thus using the whole season for growth and propegation. plants are chemically triggered by the sun's cycle, right??? well the closer the sun the faster the wavelength, the more blue the spectrum....summer time growth. the further away, the slower the wavelength, the redder the spec.......autumn flowering. over the vast millenia, plants have learned when these triggers are to take affect. hope this helps to understand

 

smthing on tv ~ a light sheet made w/organic LEDs!

o brave new world

 

From a yield perspective....a watt is a watt of power and the baseline for acceptable yields has been set by HID lighting.
Some people would just like to hear that there is a new light out there that gives more yield per watt. Hopefully LED can get there. I think it could get there...especially with a very short SOG garden. The future will be interesting.

As an example of the wattage issue....Flouro's are great. But I don't think 1000w of flouro's would out yield 1000w of HID...so what are we still doing? Using HID's.