For 20K SE's it's Radium or nothing. I've tried a variety of other 20K SE's and I dont care if the bulbs are 100 bucks (shop around you might get them for 75). The light output and color are incredible.
Keeping this in Mind, you can also get lower color temp bulbs that have that 20K appearance. I've run with Reef Optic's 14K's that were close in color to the Radiums but the output was lower. I think I could pick those up for 35 bucks a pop so I'd try those first to see if you like the color.
I run a pair of Lumatek 250W Ballasts and can run either SE or DE's. I just tend to get better coverage with the SE's.
