how long do XM 20K bulbs last?

[dwillingm]

I replaced my XM 20k bulb after 1 year, and I really couldnt tell any difference at all with the new bulb. The color appeared the same and it wasnt any brighter looking. I was wondering how often people using these bulbs repalce them, and if they can go longer then a year.

 

[Marsfrogie]

Bump for this, also curious about other people's first hand experiences.

 

[aninjaatemyshoe]

Most people like to replace them at a year. Though your eye can't tell the difference, it is quite possible that the spectrum shifted and/or the intensity fell. By the time you can visibly tell the difference, the spectrum has drastically changed and the intensity probably has fallen quite a bit. Another problem with a bulb with such a blue color is that MH bulbs lean towards the blue end of the spectrum as they age, so you really can't tell.

 

[eddie c]

check out this article
http://reefkeeping.com/issues/2007-04/ac/index.php

 

[jnb]

My first year - about 11 mths I became curious - ordered new ones - before I put them in I set my camera on auto, let me tell me what shutter speed and f stop it was going to use, took a picture, put in the new bulbs used the same (manual) setting took a picture - the top row is before change

all this told me is that the new bulbs were brighter (but it is before running 100 hours) - but still, it was enlightening

Without doing this, I didn't notice the difference or know if the corals became happier

 

[dwillingm]

nice pics. there is a big difference there, and probably more of a difference then can be explained by the bulbs being in the first 100 hours. i guess its time to change my bulbs.

 

[jnb]

if your corals are otherwise happy maybe not - I am going to go to one year thgis time notwithstanding the degradation maybe longer until my corals complain maybe

<a href=showthread.php?s=&postid=9855316#post9855316 target=_blank>Originally posted</a> by dwillingm
nice pics. there is a big difference there, and probably more of a difference then can be explained by the bulbs being in the first 100 hours. i guess its time to change my bulbs.

 

[markandkristen]

i also look at the actuall inside if its looking reall black so to speak then i think its time to change. but i think if we get a year running lets say 10 hours a day thats pretty good.
now i run mine around 6-7 hours a day so im hoping to get 14 months. i do know that i added the lumenmax 2 reflector and man do they reflect the light. yow i have the 30" tank and my ricordias are still trying to get used to the intensity.

 

[snommisbor]

I think the whole point of replacing once a year is to not wait until the corals start to complain but to keep them happy year round. YOu could probably go longer but why make the corals go through the light change to save some money. Plus every year makes it easier to remember.