This is my setup, and experience with LEDs.
It started out as 12 10Watt Chinese LEDs over my 90 gallon(24" tall). The heat sink is just angled aluminum from homedepot and does not work well at full power. I only run the LEDs at 75% full power to avoid overheating. To compensate for this I added 2 T5NO bulbs down the middle. I really wish I had a PAR meter so I would have a clue about the amount of light I am producing, all I can do is guess. I have no idea if I have low, medium, high, or ultra high light.
This picture was taken on 5/20/2011. I had just planted some DHG Belem to be grown emersed. There is a layer of Osmocoat fertilizer under the Eco-Complete.
This picture was taken on 10/27/2011. The DHG had filled in nicely on the right side (due to a white wall on the right side I think). I was running the LEDs at 75% with the T5NO lights on for 10 hours a day during the emersed period. I flooded the tank and planted some Crypticorne Wendtii from another tank.
This picture was taken on 5/16/2012. The DHG has not spread but has stayed healthy. The Crypts have grown nicely and are spreading but slowly. The Rotala Magenta was planted in January and I have barely been able to keep it alive. I planted some Corkscrew Vals at the same time and they have all died but the one next to the overflow. The LEDs had been running at 75% for 7 hours a day with the T5NO running for 4 hours a day. I fertilized with a low dose of dry ferts about every 8 weeks, and used Osmocoat in Gel caps for the root zone once. No co2 was used.
From my observations over the past year I would guess that I have low to medium light levels with this setup. While I did get growth from all my plants it was by no means fast, but I did not fertilize much or run co2 so that may have made a difference. I setup pressurized co2 last week and I almost have it dialed in. Im hopping that the addition of co2 and more dosing will get the DHG to actually spread now.
[Edit] I forgot to add that I have some Ricca mini entangled with my DHG. That stuff is growing like a weed and I always have to pull it out of my grass or it will take over.