I have a 20L linked in my signature where you will see a Coralife t5HO fixtures 36" with x1 6,700K bulb and one colormax bulb. Each bulb is 39watts and the fixture is suspended over the tank.
If you want to grow an HC carpet and want to do it right the first time. I highly recommend doing the DSM. Do your research too.
Hope this links helps.
http://www.shrimpnow.com/content.php...y-Start-Method