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Anchorage, Alaska

I found a neat article on making a seed starting box from Christmas lights for about $5. He used blue and red LED tree lights and showed good results. Be sure to read Update #2 at the bottom of the article.


http://www.cheapvegetablegardener.com/2009/01/cheap-led-light-and-grow-box.html

1/6/2010 10:10:24 AM

phoenix AZ

Looks like a great idea.
heres a piece from NASA about the best ratio's of blue to red The researchers found our that blue and red light is essential for plant growth and, in general, a percentage of 8% blue LEDs and 92% red LEDs, both with the same frequency and relative intensity per LED, are enough for a harmonious evolution. Blue has a smaller influence than red however a percentage between 1% and 20% of blue light can be selected.

1/6/2010 10:20:54 AM

Annapolis Valley Nova Scotia

They can't be the same frequency, or they would be the same color.

1/6/2010 12:07:03 PM

Annapolis Valley Nova Scotia

Approximate wavelength (in vacuum) and frequency ranges for the various colors


Frequency (THz)
red 384 - 482
orange 482 - 503
yellow 503 - 520
green 520 - 610
Blue 610 - 659
violet 659 - 769



1 terahertz (THz) = 103 GHz = 106 MHz = 1012 Hz,

white light is a mixture of the colors of the visible spectra.

1/6/2010 12:12:39 PM

Nova Scotia

great facts Phil I sell leds and didn't know those #'s

1/6/2010 12:21:03 PM

Little-TON - Colorado

Best part on LED's would be lack of heat thats associated with high intensity lights......Interesting.....However different spectrums are needed by plant growth at different times.....All very interesting....What do the chronic growers use......???

1/6/2010 1:37:47 PM

phoenix AZ

Yup your right, can't be the same frequency. I just copied and pasted that from an article I read this morning without looking to closely, sorry. WIZ for just starting the seedling I think you would want to go with a red LED If you could only get 1 color.

1/6/2010 9:46:11 PM

Glosta

red light alone will cause spindly plants, they will grow fast but they will not have good tissue density. Blue light alone will cause more dense cell growth, plants will be more compact but have better cell structure. Plants need both lights to have optimal growth. I read a study by Nasa researchers that concluded that 85% blue and 15% red was the best lighting config for optimal plant growth.

1/7/2010 11:12:42 AM

Glosta

Correction, 85% red and 15% blue for optimal growth

1/7/2010 11:23:32 AM

Western PA

A hertz is 1 cycle per second

1000 Hz = 1 Khz hundreds of hertzs
1000 KHz = 1 MHz thousands of hertzs
1000 MHz = 1 GHz Millions of hertz
1000 GHz = 1 THz billions of herz
1000 THz = Trillions of Herts

I am not familiar with with 1012 Hz being = to 106 MHz.
is this used for leds freq??

1/7/2010 9:24:54 PM

Western PA

Correction:

I worded the above post wrong

KHz = thousands of hertz
MHz = millions of hertz
GHz = Billions of hertz
Thz = Trillions of hertz

1/7/2010 9:29:14 PM

Annapolis Valley Nova Scotia

Yep you are right the 10 to the minus 3 , 6, 12 didn't come out in my post

1/8/2010 3:49:28 PM