New to MH is this bulb dead?

[Gordonious]

I purchased a new MH fixture from a DRC member(thanks tom-annette) and I was planning on buying a new bulb. I figured the bulb might be a little dull, but now I am starting to wonder if it got damaged(possibly while I was obsessively cleaning the fixture) and may now be damaging my corals. My corals looked better then ever last night, but 2-3 tonight look like crap.

1) This is what the bulb looks like in the reflection. As well as the light it puts out in the second picture. What do you think?

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2) What bulbs would people recommend for this type of set up and where would I get them? The tank it will be over is mixed
<A HREF="http://www.drsfostersmith.com/Product/Prod_Display.cfm?pcatid=13922&Ntt=metal%20halide&Ntk=All&Ntx=mode+matchallpartial&Np=1&N=2004&Nty=1">(Details here)</A> It is a "Aqualight Advanced Series HQI Metal Halide Fixture".

Jon

[sinkingbeach]

Hey Jon, were you using VHO's or PC's before using the halides? It's possible you bumped up the lighting to much to quickly and the corals will bleach from that. You might want to use a screen or something to shield the corals for a week or two til they acclimate to the brighter light.

If that's not the case I don't know what to tell you:D

[Gordonious]

Damn it I typed a response and my screen blinked and that window disappeared! So frustrating. I gtg I have HW to do, but really quickly. Before the MH fixture I had a PC bulb and a single T5 bulb which had been used for a long time.(I knew I badly need to upgrade because of some things that died on me two weeks ago)

The two coral that are having the worst time are a very small digi and a piece of xenia.

Originally I had egg create between the coral and the light, but both me and the gf agreed the light looked weak to us so I moved the egg crate. Last night when the corals were looking better then ever I had the fixture mounted up very high. I pulled it down closer to the water this morning since the light still didn't look bright to me. Shouldn't have played with it probably since the corals were happy, but I did.

I'll try to get pics of the corals if I can, but I have school work to do for now. :-(

I suppose my biggest question which I didn't type out: "Does that bulb look normal to everyone?" I also just realized I forgot to post the pics!

Thanks for the response.
Jon

[kaptken]

well, you now have about the same amount, or at least wattage of light over half of the tank, that you used to have over the whole tank. I take it that was your 96 watt PC and T5 hood to the right, on the floor.? so intesity is one difference. but there looks like a big change in spectrum/ the 150w DE halide looks like probably a 20,000K lamp. which is bluer and less intense visibly.

when intensity and spectrum change abruptly, the zooxanthelea have to change their mix to adapt to the new spectrum. so it takes time. there are a broad range of zooxanthelea in coral polyps all the time. but the ones that best use the predominant spectrum become the most abundant. change the spectrum and some will die off while the other minority types will have to multiply to take over the job. brown coral for a while.

or thats the theory i have read somewhere.

opinions vary. but you did make a big change. expect a reaction.

[Gordonious]

Eh, I dunno Ken. Sorry I left out some of the details because I was in a rush and well also people don't like to read long threads. The 96W PC you spotted and the T5 were above the tank, but that PC was actinic. There was a lot of blue over the tanks for a while now and I left the blue on longer then the T5s for dusk and dawn.

Pics of the coral coming soon.

[Gordonious]

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[MinibowMatt]

jon- back to your original question, there is no good way to look at a bulb and see if it is bad. Age is a good indicator, as is color, but true knowledge of whether its spectrum has shifted or not, is only available with a par meter...

As for what bulb, go for the pheonix 14K. Its the best combo of Par, color, and growth..

[Gordonious]

Lol, ok I suppose I should have asked the question a bit different. I know that we can't really look at the light coming from the bulb and tell it's intensity and spectrum, but how about the physical bulb itself. In the picture of the reflection on the left hand side of the bulb it is red. It doesn't show up in the picture as much as it does when you look at it in person.

So my new clearer question: "Does the bulb itself (or it's reflection) and it's red color on the one end look as if it's damaged? "

I have to admit though that I am a bit worried the reason the corals look off may be because of a shift in PH. It seemed to me as if the polyps of my xenia were pulsing a lot faster last night then they have been.(though Steph disagrees with me and says they look normal) I've heard that the pH often effects the speed at which they pulse, so tonight I am going to hook a pin point pH probe up to the system again.

[MinibowMatt]

that is normal IMO. If it isnt "liquid glass red" than its fine. IME, a little schmutz builds up on the inside of the inner halide containing envelope. As that schmutz gets hot, it starts to glow orangey-red.

[Gordonious]

Cool thanks. I think I'll take your advice and start pricing out pheonix 14K 140W bulbs.