Do fluorescent T5 lamps have "break-in" period?
 

I installed my new 48" T5 fixture (2x 10K, 2x actinic) a few days ago, and when I first powered it up, although the light intensity was impressive, the color wasn't that great. The tank sorta had a sickly yellowish-green hue.

But yesterday and today, it seems to look better. Is it just my imagination (maybe I just got used to the color?), or did the color change after the first day of use?

--Michael

All fluorescent lamps have a break in or burn in period. Color changes and brightness can change during this period. Typically most lamps are burned in at or after 100 hours of operation.

With fluorescent lamps the phosphor coating requires a slight burn in period. The mercury inside the lamp will alter the operating pressure of the lamp. A burn in period with a few on/off (operating and cooling) cycles is required for the lamp to fully stabilize. This assures the mercury is positioned properly within the lamp.