i have also built my own led grow light will post up some pictures bit later i used 150 super bright 5mm red led's i run them in chains of six per 1ohm resister then divided them in to two chains of 75 for maximum power and no power lose running off 12 volt 2000ma... using a pre drilled matrix pcb board to mount led's on.. i found this is really good for promoting root growth in cuttings/clones i was lucky as i was given a bag of 180 red LED's

use the best led's you can get (for your money)as the cheaper one's like they use in the ufo grow lights just really not that great especially if you want to grow more than 1 plant....look out for the post later i will call it (pic's of home made led grow light) i will take some nice close ups of the wireing and the led's