how long before you replace halide lamps?

[gioNVA]

I know a few people here run XM 20K 400w. How long do you go before replacing the bulbs? I've been using them for ~6 months, 6 hours/day and notice a shift in color over the past couple of days. They are not as blue/bright and notice a yellowish tint. At first I thought it was the water so I tried my old 250w 14k and that looked pretty good.

 

Maybe time for a bulb change.

[ReeferMan]

Sounds pretty quick being that they are only on 6 hours a day

[fab]

if you can see the color change then you are finished with those lights for your display tank. The fact that you see yellowish color means the red spectrum output is overtaking the blue end of the spectrum. It may be possible for you to continue using these lamps over an algae growing refugium and get a bit of a second life out of them.

 

fab

[flowerseller]

Have been changing XM bulbs at 12 to 15 months.

 

never noticed such a quick color change

[Almon]

I thought this was a good article of the decline of bulbs over time http://www.reefkeeping.com/issues/2007-04/ac/index.php

 

 

 

"After six months, the six bulbs' intensity was still 78-84% of their initial output (average, 81.5%). Even after 12 months their output had only fallen to 72-79% of the initial level (average, 75.7%)."

[dandy7200]

I thought this was a good article of the decline of bulbs over time http://www.reefkeeping.com/issues/2007-04/ac/index.php

 

 

 

"After six months, the six bulbs' intensity was still 78-84% of their initial output (average, 81.5%). Even after 12 months their output had only fallen to 72-79% of the initial level (average, 75.7%)."

 

 

I liked that article too. The big problem I have is if I ran 400w vs 250's the power consumption would quickly eat up any savings I had in bulb replacement and I have never needed more than faded 10k XM's to get sticks to grow.

 

Fab, I don't think macro algae would grow very well even in a faded spectrum with 20k bulbs especially not XM's, I could be wrong though, never tried it, seems like possibly a good idea for 10k bulbs though.

[Lee Stearns]

I have been running 10K AB 250 DEs and have found that running 7 or more hours they needed replacing just shy of 12 months- I cut back to about 6 hours a day and they are making it to 12 months- Mine seem to get duller and just a little yellow- I just this week changed to the pheonix 14k and see a marked difference in the crisp white light