Help building an LED panel

[juanitos]

 

people really hate on the ebay china LEDs, so idk
 
so like .5x.5 meter box? yeah that could work (allthough you wouldn't want all red... need one blue atleast). IIbuckshot uses 10x10w white led for 1.5x.5 meter
 
 
No the emitters already have a lens, not focused which is why its not round and they have wide viewing angle.

 

[filmost]

 
Coincidentally, I was playing with LED wavelength choices today as well.   
 
Not sure I understand your wavelength choices. 
 
450nm seems a little too far from the strong, and rather narrow, Chlor B absorption peak at that happen at 480nm.  Yea, 450 tickles the carotenes, but so would an ideal 480. 
 
Also, the red Chlo A peak is closer to 670~680 than 650. The Chlor B peak at 650 is not very strong.  I wonder if it could be skipped altogether.
 
I came up with three frequencies. 
 
435nm ChA
480nm ChB and Carotenes.  Since this is the main ChB, and will also be energizing the carotenes, I was thinking of throwing in more of these emitters.
670~680 for the second ChA peak, and to add some generic 'red' to the mix for the plant's peace of mind.
 
Finding affordable, sufficiently powerful LEDs may be the hard part.  I haven't done much Fleabay searching yet, but did discover that a pure 435 emitter is hard to find.  The typical advertized wavelength is "420~435," which will, I suppose, have to be close enough!
 
Fan requirements will follow the size of the heatsink you nail everything to.  A big finned piece of extruded aluminum should be able to radiate quite a bit of power w/o any help.

 
You numbers are interesting, b/c most places I have read use 430, 450, 640, and 660 as the peaks. For example here and here.  Ultimately after lots of searching, I think nixing the 430 would be okay it seems most LED fixtures favor the red over the blue anyway.

 

[Geonerd]

Yea, there is confusion as to the exact wavelengths.
For better or worse, I was reading from http://www.life.illinois.edu/govindjee/photosynBook/Chapter9.pdf
 

 

[Cyrus-the-virus]

Just a suggestion but why not use a few white COB led's instead of a bunch of low power monochromes? How big of a space are you planing on growing in?
 
My suggestion is to grab some cree CXA 3050 or bridgelux vero 29 cobs and bolt them to some cheap CPU heatsinks off amazon. Drive them at 0.7-1.4 amps and put one for every square foot or so of grow space 12-18 inches above the plant. Later on if you want to get fancy grab a par meter and balance your spectrum using low power monochrome LED's.

Quick and dirty math, but you could build a 50watt COB based LED panel for about $100. Four of those could hypothetically replace a 250-400 watt HID in a 3'x3' area, without the heat issues that occumpany HID lighting and should provide years of growing without needing replacment.

Just another school of thought. Good luck, check out amazon, digikey, jameco, heatsinkusa, rapidLED, and hortilux for idea's and components.