what is the life span of T5's?

I've read anywhere from 6-10 months? Opinions? I run mine about 8 hours a day.

I guess life span may not be the right term, I know they will last a long time but the time frame when the spectrum would start to change and not be good for coral growth.

 

It depends on the brand and how they are cooled. Generally 12 to 18 months if they are well ventilated for high end bulbs.

 

wow...that is way longer than I thought. I have a fan in the fixture and they are ATI bulbs.

 

I talk to people all the time that use our T5 bulbs for 12+ months no problem.

 

The guy at my LFS who is selling me my ATI's to replace the old ones that came in my fixture told me about every 14 months.

 

There's nice article about T5 life and ill try to find it and share...
Above very long tank (that was some store in Germany if I'm not wrong) they installed 2 light fixtures, fragged same corals and placed similar size frags on both sides of the tank, they was testing which bulbs color is better for growth, coloration etc, and bulbs life at the same time.
Oldfishkeeper is right, they proved that HO T5 life ends after about 9 months, almost all my friends from Germany or Poland are changing bulbs every 6 months, well I do every 9.

 

+1 I do 6-9 months on daylight bulbs.Actinics last a little longer.

 

As promised...

http://archiv.korallenriff.de/Lichttest/T5-1.pdf

Enjoy.

 

very interesting article - thx for sharing! I had not heard of aquascience unless that is a name synonymous with Geissman.?

 

I'm glad to hear that you like it
Well as long as I remember AquaScience are Fauna Marin product.
I used to have Fauna Marin T5 fixture but wasn't able to find bulbs in USA I think they only exported fixtures.
Very well made product by the way.