Brand new 10K MH bulbs yellow

Jeff · #1 03-10-2005, 03:32 AM

I have a few brand new 10K bulbs, been on the tank for about two weeks and four weeks now (I staggered them). They are horribly grotesquely yellow in colour. They are much more yellow than the 1 year 10K (same brand) that they are replacing. Picked up from a local store just over a year ago. Bought 4 on boxing day.

Has anyone encountered bad bulbs before?

I'm aware MH bulbs are yellowish when first used until they break in. These are well past any usual break-in phase that I've experienced before.

Could perhaps my ballast be going? Would that affect bulb colour temperature? My ballast is quite old. I've been reef keeping for about 10 years and I still have my original Hamilton dual ballast.

It's really quite bugging me so if anyone has some thoughts I'd appreciate it.

Cheers

Invigor · #2 03-10-2005, 03:47 AM

it could be the kind of bulb you're running on a certain kind of ballast. aqualine bushke 10000k don't look good unless they're on an HQI ballast

Chin_Lee · #3 03-10-2005, 06:47 AM

what brand bulbs are they Jeff? I had a SA 10000 k bulb that was very yellow for about 4 weeks and now its either less yellow or I've become accustom.

danny zubot · #4 03-10-2005, 03:01 PM

Could you test your old bulb against the new bulb on someone elses balast?

Jeff · #5 03-11-2005, 03:32 AM

All good suggestions. I'm pretty sure it's not the "brand" of bulb as I bought four and the two I used for the past year were just fine with the same ballast.

Trying it on someone elses ballast sounds like a good plan. The colour is SO yellow it's actually quite distracting to the eye, especially since I tend to favour a very white light.

Bob I · #6 03-11-2005, 04:09 AM

Quote:

Originally Posted by Jeff

Could perhaps my ballast be going? Would that affect bulb colour temperature? My ballast is quite old. I've been reef keeping for about 10 years and I still have my original Hamilton dual ballast.

Cheers

If your ballast runs your old bulbs with no problem, I would say the problem is not the ballast. It sounds like a defective bulb.

Quinster · #7 03-11-2005, 01:02 PM

I purchased 2 of the same brand 250W 10000K bulbs..1 fired up right away and looked like a 14 000K, the other took a while but when it fired it looked like a 6500K, contacted the retailer who sent me a replacement and when I fired it, it looked like a 10 000K which really threw off the look of the 14 000K looking one, so another was sent out, it was between the 10 and 14K's...so I picked the closest 2 (after 4 months of emails and wondering what to do) and sent the other 2 back. They were all the same bulb, same K rating running on the same type of ballasts.

Aquattro · #8 03-11-2005, 01:58 PM

One manufaturer in particular sells 175w 10k, and from my experience, 60%-70% have that yellow color that makes the tank looked peed in....
Some are ok, but more often than not, at least last year, more were yellow instead of white.

Moral of the story...even if youhave some from the same place, the replacements certainly could be yellow.

Invigor · #9 03-11-2005, 02:54 PM

maybe they're cheapy japanese bulbs or something not up to snuff on german mh fishtank colors?

Jeff · #10 03-12-2005, 05:07 PM

Which manufacturer is that that has 60-70% yellow bulbs?

Thanks