I have an edge with 4 dimmable cree cool white xpgs myself. For mine, I haven't been able to get my driver up to 100% w/o getting algae. I have CO2 set to make my drop checker lime-green and dose EI. I normally run my LEDs at 60%-ish.
W/ my setup, I am able to grow HC in the foreground, although it hasn't quite spread to the corners yet. I did have DHG in the tank, and it grew well, but i removed it as it was too invasive.
Here's a pic of my tank currently, the HC is about 2 months old and started as two pots from the LFS.
Good luck with the tank, and post some pics!