Burn In?

[SCU33ZE]

Hi, I recently got a new Coralife Trichromatic NO tube for my tank.
The first day it was pretty dull and i was about to go return/exchange but i decided to go the day after.

Now 12 hours of use later its brighter and whiter than ever.

Is this normal and is it some kind of "burn in" period?

Any help would be great!

Thanks

 

[Slappy*McFish]

I've noticed that before with the Trichromatics, too.