problems with metal halide

[scubacane]

I just bought a JBJ 28g HQI nanocube and am cycling my live rock with no lights. Periodically I will turn the lights on to see how they look. Last night my metal halide bulb turned off for no apparent reason after being on for about 15 min. When I took a look there appears to be some brown residue in the bottom of the gas compartment and there are two small pieces of loose glass in the outer glass casing. I tried to turn it on again and it begins to flicker for about 5-7 seconds and then turns off again. I assume my electronic ballast must be OK and this has to be a bad bulb but being new to metal halides I wasnt sure. Any help is appreciated.

[Reef Newb]

Sounds like a bad bulb. The bulbs for MH are pretty delicate so I would imagine that would be the issue. If it is not the problem, it is a place to start. If you get a new bulb and are still having issues then it is most likely the ballast. But from the sound of things you just have a broken bulb.

[Phurst]

I agree that it's likely the bulb. The brown residue is likely the halides. They're solids at room temperature, but turn to gas while the bulb is firing. The glass however is more worrisome. I don;t think I've ever seen a HQI bulb with loose glass in it. I wouls definitely try a different bulb first.

[CarmieJo]

If it is a new tank I would contact JBJ.

[scubacane]

I contacted nanotuners where I got the tank. They seem to think its the ballast and are sending me a new one to try.They said the bulb shoudnt fire at all if it was dead.They werent concerned about the loose glass- said they see it from time to time. In the meantime I think it would be easier to try a new bulb - it never hurts to have a spare even if it turns out to be a ballast problem.

[Phurst]

Glad to know they're standing behind the stuff they sell. Please let us know if it turned out to be the ballast or bulb.

[scubacane]

Phurst- ARRGH to you - FSM is the true path to enlightenment and happiness!

[Phurst]

LOL, rAmen :)

[scubacane]

I took the bulb out again, cleaned the contacts with a pencil eraser and guess what - fired up right away , good as new!

[Phurst]

Wow, that's strange. Glad it's working though.