It might take as long as 2 weeks but I think you'll know after 2 or 3 days whether they're going to do it for you or not, ie., no need to suffer through a whole month.

Been a long time since I ran Hamilton's .. like .. I might have been in my 20's still .. wow I don't think I needed to realize that. Anyhow. Ushio's are probably my favourite 10k lamp. Phoenix 14k might be something you want to try out as well but not much is going to touch the Ushio for PAR in the 250w range, they're really one of the better ones.

Do you know what ballasts are in that fixture? Might make a difference for lamp selection.

It is the hamilton Belize, and the ballasts are electronic hamilton brand.

Yes. The Hamilton's will only get yellower as time goes on. If you don't like them now, it will only get worse. Most bulbs won't burn true to the Kelvin printed on the box. 10,000K is white, but most 10K bulbs look yellow on most ballasts. Of course every ballast will burn every bulb a little different.

Again, not what I want to hear... I am picking up the phone right now and getting some more Ushio's. Thanks everyone.

Ah rats, no one is open yet... So I am thinking, and YES it hurts!

I was running Ushio 10K, and I loved them, very very white. I didn't like the Pheonix 14K as it was not as bright and too blue.... What do you all think about Ushio 14K's? I am thinking they will probably be brighter than the Pheonix, but never seen them. Any thoughts would be appreciated.

I would go with what you like (ushio 10k), since each bulb is quite different and the only way to get exactly what you had and what you like is to buy the same thing.

I agree most are different, i had a 175W 10K on my last tank that must have been 12K or above. I've been using 250W XM 10K's with a PFO ballast on my new tank, and they are bright white, Don't look yellow at all to me, white, but not yellow. For the record my room is painted yellow, so probably would offset any "yellow" look that comes from the bulbs. It's like painting, same color in 2 differnet rooms looks night and day different.

Great info... No LFS have any bulbs, but did find 2 XM 250W 10k's, and for a good price so I got them. They will have to burn in, but when googling most are stating what you said... They are very white, so I am giving them a try, if no good then back to the Ushio's and I will have to order them.

Well, the XM 250W 10000K bulbs have been running for a few hours now. In no way have they completed the burn in period, but I can say I like this brand.

Compared to the Ushio 10000K's, which were really really white... The XM I think has a better spectrum of light. The bulb isn't as intense, but the overal spectrum is nicer and the coral, rock and fish look nicer. The tank overall looks boutiqish, elegant. If you know what I mean.

I look forward to seeing what these bulbs end up putting out after a week or so. If these bulbs keep improving with the burn in, I think I will have a new favourite.

This doesn't add up. 10K is 10K. If the Hamiltons are noticibly different then either they -or the Ushios- were not, in fact, 10K.

An analogy might be that you say the room is 20 Degrees C but the room is actually only 15 degrees. 15 is 15 and 20 is 20.

Of course, people can perceive colours differently but at the end of the day, 10K is....10K !

The only thing I can think of is that the way the bulbs are specified is loosy-goosy which might explain it but otherwise....