riiz;3243761; said:
Shouldnt be any shorter than T5, since PC bulbs are just that in U-shape.
t5 and pc are different, they are the same diameter bulb tho. but t5 have a different bulb life, and the par output is much higher when compared to pc. i dont think the bend makes that much of a difference even if some of the light output is lost because of that.
HarleyK;3242868; said:
Howdy,
Regular fluorescents once a year. Power compacts every 2 years (the above were 3 years)
You
think, or do you have any references for that? Everything I've heard is that power compacts can be used about twice as long as regular fluorescents. Please link me to a reliable source for that info.
Thanks,
HarleyK
your are right about comparision to regular flourscents, aside from t5
but im used to talking about high power lighting, reg flourscents are even considered. but i think the spectrum and par of the pc bulb degrades enough to warrant replacement after the first year.
velanarris;3244126; said:
You should be changing t5 fluorescents every 6 months as that's about the 50% mark. At 1 year they typically will not degrade any more, but they're well below optimum.
The second aspect to this is you want to change your bulbs before they become too weak, as a sudden change in intensity (replacing the bulb) can stress livestock.
t5 ho life span is 20,000 hours
they lose no more then 5% of output over there lifespan(output isnt par so that doesnt help much but they are supposed to be the longest lasting light aside from led in the hobby)
(ive heard recommended replacement after 2 years, 1.5 for actinic)
http://www.metalhalide.us/T5-HOHIGHBAY.html
(life span is on spec sheet if not on the page)
i dont have hard figures the output loss of these other bulbs but its much greater then the 5% over there lifespan
halide also lasts 20,000 hours,
manufacturers like ushio recommend 6000 hours(that 1.5 years) for aquariums , cheaper bulbs degrade faster (its a year in reef forums)
http://lib.store.yahoo.net/lib/specialty-lights/Ushio-Aqua.pdf
http://www.specialty-lights.com/aquarium-lights-faq2.html#comparet5mh
cant find any real info on life of power compacts, there a dieing breed
dr fosters says 14-24 months,
but with in reefs they may not last that long.(in reef forums most people use them no more then a year)
http://www.drsfostersmith.com/pic/article.cfm?c=3578&articleid=1035&category=586#answer_9
in comparision they also said 18-24 months for halide.
http://www.drsfostersmith.com/pic/article.cfm?c=3578&articleid=1039&category=586#answer_10
they also say replace flourscent 6-18 months(most of the time i heard a year and 6 months for vho)(i know i said pc are dieing out but vho and other regular flourscents are dead and buried)
http://www.drsfostersmith.com/pic/article.cfm?c=3578&articleid=1038&category=586#answer_8
another guide
http://www.drsfostersmith.com/pic/article.cfm?acatid=287&aid=350
ofcourse the lifespan of individual bulbs varies with different brands and kelvin ratings. usually the cheaper bulbs degrade faster. also its important to realize par and spectrum are different then light output or lumens.
