Xm 20.000k

[ds04]

Around 3 months ago i purchased 4 x 20.000k XMs 150w MH globes to replace the Sylvania 10.000K. I had been running Sylvania for 4 years on my mixed reef tank with good growth and colour on all corals soft corals, LPS,SPS. When i first changed to the XMs i loved the bright blue colour all my corals looked to have much better colour and growth. Then one day the tank didnt look as bright as it should, Working day shift i dont get to see the XMs on much. Over the next 2/3 weeks i see my SPS have stopped growing and the colour is not as good as it has been in the past. Then some of my SPS started going brown, lost all colour, Looking at the light in the tank i was thinking the XMs are off early today they should be still on,Opened the hood to find they are still on but very dull.
Has anyone else come across this before My XMs didnt even last 2/3 months.

I replaced the XMs 2 weeks ago with my old Sylvania until i purchased new globes. New globes have been in for 2 days and the colour of some of my corals at the end of the 2nd day is getting better.

[mimosa]

IME, this is very common for XM20K. Nice bright intense blue in the beginning, becoming dim in 2-3 months. How does the inner bulb tube look like? Blackened?

Are you using M59 type ballast?

[russ49merc]

I had the same problem with the xm bulbs don't like them at all.

[Ti]

oddity, haven't had that happen to my xm's yet.

[ds04]

Thanks for the replys,I am using the right ballast and no the inside of the bulb is clean a little grey not black, Only the 20.000k bulbs have gone this way as the 10.000k is OK. If it is very common for the 20.000k i wonder how i will go getting a refund :D