I found this link very useful... made a few of my own... works amazing and you can do it custom to what your looking for for like 10-25% of buying one... hope it helps...
forgot the link:
http://screwdecaf.cx/broiler.html
highly recommended for tight budgets... super simple..
Summary:
A 33 watt grow light made from 19 blue and red LEDs. Each LED is glued onto a broiler pan which acts as a heat sync. This light should be excellent for growing many forms of plants and algae. It cost me about $113 in parts and shipping to make this unit. I estimate this light to be equivalent to a 300W HID/HPS grow light.
Special thanks to Green Pine Lane for sharing the original concept of a "cookie sheet" LED grow light.
Device Part# Vendor Qty Price Total Shipping
Red LEDs XR7090RD-L1-R2-M-C-0001 LEDLightingSupply.com 15 3.97 59.55 9.81
Blue LEDs XREBLU-L1-B4-J0-0-01 LEDLightingSupply.com 4 5.38 21.52
PCB Boards 3/4in PCB Boards LBB 2 LEDLightingSupply.com 24 0.00 0.00
Resistors P3.6W-2BK-ND digikey.com 4 0.20 0.80 6.57
Terminal Strip 274-679 radioshack.com 1 3.29 3.29
Hookup Wire white 18ga 35' carquest.com 1 5.00 5.00
Hookup Wire red 18ga 35' carquest.com 1 5.00 5.00
Broiler Pan for oven Thrift Store 1 1.00 1.00
Power Supply 16.2V / 2.6A / 34W Thrift Store 1 1.00 1.00
Hookup:
3 strings of RED LEDs - 5 LEDs per string
1 string of Blue LEDs - 4 LEDs per string
Each LED in a string is connected in series
All strings are connected in parallel through terminal strip
Power:
The LEDs have different power requirements.
Blue = 4V @ 700ma max
Red = 3V @ 700ma max
Power Supply 16.2V
Will not drive LEDs to full capacity.
Blue = (3.5V @ 600mA) = 2.10W = 4 LEDs = 14V (one row)
Red = (2.8V @ 600mA) = 1.68W = 5 LEDs = 14V (three rows)
Resistance - E = I * R
(16.2V - 14V ) = 2.2V
2.6A power supply / 4 = .650A
2.2V = .65A * (R)
R = 3.38ohm
2.2V * .6A = 1.4W
Buy four 2W (or greater) 3.6 ohm resistors (one per row)