When to change light bulbs??

I purchased a corallife used light at my LFS. Since I do not know age of current bulbs, how do I know when to change them?

Thnx

 

I would change them out then date them.
( that way ya know how old they are from there on )


Ive noticed alot of people swear by changing them out every 12 months at least.
While others people will super anal about light spectrum and change them out every 6 months.

I my self go for 12 months and install all new bulbs.

The point of changing them out is to keep the spectrum of lighting consistant
in your tank for your corals.

 

Yup, change them out.

 

I go by the following: 6 months for standard fluorescent bulbs, 12 months for PC and T5.