How long do PC's last?

[gear-head]

(I apologize if this has been answered before, but I did search the forum posts and couldn't find anyhting)

What is the expected useful life of a Power Compact Flourescent bulb? I have 4 96w in my Coralife hood, they are about 7 months old.

What are the signs that they need replacing?

 

[fishfreek]

I replace mine after 9 months. 12 months is the suggested life by many manufactuers but I have found the color and intensity really drops off around 9 months.

 

[malkore]

Especially the actinic's...those will really fade out over time. Defintely replace annually.

 

[XXFirefighter]

I did mine after a year and WOW what a diff it made...

 

[Jason]

mine are only about 6 months old and I can stare Into the bulb while it's lit and it doesn't even hurt........ I have to change them when I get home.

 

[Fluff]

When you replace them, would you replace all at once or half at a time? One at a time?

 

[Smo]

PC's half at a time. Half now, the other half in 2 weeks.
MH one at a time!

 

[buggsmarinetank]

Look at the ends of the bulbs, if it looks liek you held a lighter up to the glass , then it is close to changing time. I dont know if it is true or not, but I have been told that it is a sign of the gases getting old, and they start overheating until the bulb blows out.