Fred, you can get even more bang for your buck with color corrected lamping out of the same ballast at 5500K.

FYI, I have had better luck with the lamping if the recommended "burn-in" time for initial start up is followed. Some are 50 - 100 hours uninterupted... Apparently it helps prolong the life of the lamp....
http://www.osram.com/service_corner/faq/general/fluorescent.html#faq47

Mark Heller
"Well - I oughta....." -Jackie Gleason