# 250 Metal Halide Bulb - What kelvin?



## wguttrid (Feb 20, 2006)

Hello, been shopping on ebay and came across the following metal halide bulbs (see below link)

http://cgi.ebay.com/250-Watt-Metal-...746212996QQcategoryZ46314QQrdZ1QQcmdZViewItem

Not sure of the manufcature, the prices seems reallly good though, the question I have is what do you think would give me more of a white, yellowish light in the tank.There is 65k, 10k, 14k, 20k bulbs available. Looking for best of both worlds I suppose, a lamp that looks good to the eyes (whitish/yellowish) and also is good to grow plants.

Thanks again.


----------



## Mjproost (Nov 17, 2005)

I have tried the 10k version of those plus brand bulbs with a magnetic ballast. It started out pretty plain white, and after a month or two, it burned in slighty yellow. Probably what you are looking for, but it might be a slightly different color on a different ballast. None of the colors ever really seemed to pop with it, though.

I thought these bulbs are priced about right, you get what you pay for with them. The spectrum seemed to change pretty quick and the overall life is about 1/2 of a good quality bulb. Personally, I prefer the XM brand 10k's or the Ushio brand 6500's. Plants seemed to grow a little better(so did the algae ) with the ushio, but they look very yellow to me. If I remember correctly, the XM 10k's were stark white on my magnetic ballast and just a tinge blue on my electronic ballast. The plants seemed to grow slightly slower, but I prefered the color. But, then again I like the look of my current bulb, a 9 month old XM 15k.

Just my opinion, I hope it helps!


----------



## AaronT (Apr 26, 2004)

I agree with Mjproost on this one. You get what you pay for with bulbs off of ebay most of the time. Stick with brand names. Both of the above mentioned brands are excellent. I had the 10,000k Ushios and I found those were even too yellow for my lighting tastes. A friend of mine uses the XM brand 10,000K bulbs and they look much better. They can also be had for about $50.00 a piece if you shop around a bit.


----------



## Ibn (Oct 20, 2004)

Agreed. I'm running a pair of 250W Ushio 10,000k and they appear a bit yellowish still (much better than 6,500k though).


----------



## DelawareJim (Nov 15, 2005)

I've run 5500K & 6500K in the past and they seem positively yellow compared to 10,000K. 5500K is supposed to most closely approximate noon-day sun though.

A lot of reefers I know are running 15,000K's for their macroalgae and clams but it starts to look a bit blue for my tastes.

Cheers.
Jim


----------



## wguttrid (Feb 20, 2006)

Well guys, just got my Xm 15,000 bulbs, and so far I really like the colour. They are white with a tint of blue which I kinda like. They have been up and running only 4 hours, the person at my LFS said that when they burn in they will go a little whiter. 

Mjproost, how did you colour of your bulbs change over the life, you said you have had them for 9 months now. Also do you have freshwater plants and if so how are they making out as that is the purpose i have these bulbs. The 15K is high so still hope my plants grow good.


----------



## Mjproost (Nov 17, 2005)

Well, my bulb started out quite blue at first. But, over time it has whitened some, but it is still noticeably blue. As far as plant growth, it is just fine. It doesn't seem as fast as when I had the 6500 Ushio, but close to the 10k bulbs I have had. But, there could be other factors affecting that, this is by no means a scientific analysis. The difference might be because the PAR on the 15k bulbs is much lower than with the 6500k's and slightly lower than the 10k. But, I have almost zero algae to speak of, even no green spot. My biggest issue with growth and MH is dealing with shading. You have to be careful that your high light plants have a clear access to the light. Glosso has always difficult for me with MH. Hairgrass seems to do OK, but grows a little than with CF for me. 

Honestly, I like the look of the 15k bulb. But, it is not for everyone.

I am in the process of raiding my 250 watt MH lit 37 gallon tank to set up other tanks. I will post picks when I get it planted again, probably this weekend.


----------

