when to change/what type

[Kenmx10]

How often should you change your bulbs. I have a coralife 48" unit with 4 bulbs ,260w . Its used and im not sure whats in it. What are the recommended bulb replacements for a salt tank w/fish and live rock? Theres a sticker on back that says 07/10/06. Is this the installed date or the change date?

[kev-kev]

I had that light a couple years ago, change-em every year. At least thats recommended. They lose a little intensity over 8-12 mo. IMO Kev

[snulma1]

since you are using PC's, I would replace them every 6-8 months, especially since you're probably running them for around 12 hrs a day or more. I find that the color shifts after 6 months and your growth dwindles.