URI-VHO Bulb Question?

[jond]

I am running URI bulbs on an Icecap 660. The bulbs are about nine months old now. I believe that they recommend change at 12-13 months. What are your experiences with useful life of the bulb and can I change all at once, or spread the change out? I have 3-24" 75W bulbs.
Thanks

 

[jimi]

I usually change mine about every nine months. It is better to spread the change out over a few days.