I was interrupted trying to catch a flight while working on the last project log.  So continuing...

I also found that 3 Watt 660nm(Red) LED's were slightly less costly at about $.90 each.  So the LED's were within reach from a cost stand-point.  The question became how many and how to power the LED's.  Searching online I found that MeanWell offers a line of IP-67(fully waterproof) constant current power supplies.  I found of pair of the 36 Watt MeanWell supplies on Ebay for $19 each.   

With 72 Watt's of LED's I needed some way to dissipate the heat that the LED's would generate and some way of mounting the LED's.  I decided that I could fill both requirements by using a large heatsink as mounting for the LED's.  By using Thermal epoxy I didn't have to drill into the heatsink to mount the LED's.  

So the home made LED Grow light is two 36 Watt power supplies each driving ten 3 Watt 660nm (Red) LED's and five 3 Watt 450nm (Blue) LED's.  Giving me a total of 30 LED's being driven by a two constant current 700mA power supplies.  Mounted to a large heatsink.