I've built and I am using some of these LED's in my reef tank setup.  Most notably, I have a rigged a 50W broadband (chlorophyll absorption friendly) LED over the refugium  of my 55 gal tank.  It's been running about 12 hours every night for the last 6 months:

This LED uses 115 VAC.  The refugium grows chaetomorpha to reduce nitrates and phosphates in the tank.

I also have  a three-50W LED prototype that runs on 36VDC over another tank (2 cool white's with a broadband in the middle).  I'll post images of that soon.