Halide lighting color and temp

[BCT182]

I have noticed that my three XM 20k bulbs burn fairly blue for the first three to four hours the lights are on. Towards the end of my 6 hour photo period the bulbs look like 10k's to me.

Above my tank are three 250 watt single end 20k XM bulbs with ceramic sockets and lumen-bright reflectors. My canopy has the standard opening across the back, but the sides, front, and top are fully enclosed. No fans, no vents. I have not had an issue with heat as my filtration in a separate, climate controlled area.

The ballast are 250 Hamilton Standard NON HQI ballasts. They are only two months old, as are the bulbs. The ballast are below the aquarium. They are the only items down there. No fans, not vents, nothing.

Am I crazy, or could the bulbs overheating due to lack of cool air, and causing a color shift?

Could the ballasts be heating up causing the color shift?


If I am insane feel free to tell me....

 

[returnofsid]

You are insane.

However, you may be right about your bulbs. Take a picture of them, an hour into their day cycle. Take another picture of them, after you think they've shifted. Compare the 2 pictures. This will help you decide if you're not only insane, but also crazy about your light bulbs.

 

[ac7av]

That’s a great idea about taking a picture of the lights.

It sounds like they are heating up a bit.

If you have a table top fan or something similar you could set it up to blow across the fixture and test if they are overheating.

 

[roblou]

Yes, it's my understanding that as the bulb gets hotter, the color gets whiter. If you add some air movement in your canopy, I think you'll see less color shift.

HTH,

Rob

 

[BCT182]

Thats an excellent idea. I will do this on Sunday. I will take a photo every hour and post my results. I will use a tripod and make sure all light is absent in the room for every photo.

 

[BCT182]

Can someone suggest a quiet running fan that is also fairly high power? Also, would a computer fan work? If so would that be difficult to wire up?

 

[returnofsid]

I've heard that Ice cap makes some very good ones, but I'm personally unfamiliar with them. I've also heard of people using computer fans. I think you'd need a special power supply. I think you can get everything you need at Radio Shack.

 

[mfinn]

I am not a big fan of spending $40+ per fan for something that sounds like a jet taking off when they are running at full power.
So I'd suggest looking at something like the 12v Vantec Stealth fans. They generally run approx $10 to $12 each. You would also have to buy a powersupply like a wall wort.

 

[mfinn]

Wiring them up is pretty simple. Match colors.
I have tried several pc fans, like the Scythe Slipstream ( SY1225SL 12H ) and some others that I can't remember, but always come back to the Vantecs.
dBA vs. cfm.

 

[roblou]

Radio Shack also sells some fans that run on AC power, you just have to splice on a power cord. I've been using 1 for quite some time and it's not nearly as noisy as the ice cap fans. This is the one I have, $25, 65CFM (no specs for dBA):

http://www.radioshack.com/product/index.jsp?productId=2102825

 

[mfinn]

IMO anything that's over 35dBA's is too noisey.
I've tried many of the 120v ones and they don't even compare to the 12v ones when it comes to how much noise they make.
http://bestbyte.net/merchant/mercha...ode=FA12VAST&Category_Code=FA12&Store_Code=BB

 

[mfinn]

Here is a Scythe that has good numbers. dBA vs. cfm

http://www.compsource.com/ttechnote.asp?part_no=SY1225SL12H&vid=2338&src=F

 

[BCT182]

awesome stuff guys. I will take some photos this weekend and maybe do the fans either way.

 

[servicky]

i just got 3-250 de 10k reeflux bulbs ill tell ya what i hate um.... one is brite white one is decent blue and one is almost yellow green and all have different brightness to them thank god i ended up with the brightest one in the center... anyone have the same issue there only 3 days old....

 

[returnofsid]

i just got 3-250 de 10k reeflux bulbs ill tell ya what i hate um.... one is brite white one is decent blue and one is almost yellow green and all have different brightness to them thank god i ended up with the brightest one in the center... anyone have the same issue there only 3 days old....

Did you make sure that all of the double ended bulbs are facing the same direction? A lot of people don't know that the double ended bulbs do have an "up" and "down." I didn't know, until I had a 14K DE 150MH bulb that was GREEN. If I remember correctly, the "nipple" needs to be facing up, away from the water.

 

[servicky]

WHAT>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> NO FRIGGIN WAY.... Wait they have ears on the bulbs dont they (CERAMIC)... where they only fit in one way... brb going to take one out now......

 

[servicky]

ok i checked you can not put the bulbs in wrong.. they have ceramic feet on them to determine north and south on the bulb. weewww i was like these damn bulbs i just bought.....

 

[apollothesun]

Is it a dual ballast or if theyre single,the same ballasts?

 

[returnofsid]

WHAT>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> NO FRIGGIN WAY.... Wait they have ears on the bulbs dont they (CERAMIC)... where they only fit in one way... brb going to take one out now......

ok i checked you can not put the bulbs in wrong.. they have ceramic feet on them to determine north and south on the bulb. weewww i was like these damn bulbs i just bought.....

So the bulbs couldn't be "spun?" They must be different than 150 DE bulbs. With my 150DE bulbs, they can be put in "upside down." There's a nipple, on the glass center, that needs to be pointing up, away from the water.

Since you have one that's firing at the right color temperature, try swapping out ballasts, with each other and see if that changes things. It might help you narrow down the problem to a bad, or improperly firing, ballast.