Is my bulb dead????

cool.

 

OK I just ordered the new bulb its 250W 20000K [smiley=2thumbsup.gif]

Now my question is will my corals grow slower under that bluish spectrum than they would under the 6500K?


Ps. I love the color of 20000K [smiley=laughingsmiley2.gif]

 

The biggest challenge with Reef lighting is finding a balance between what is pleasing to the eye and what your corals need. The trend towards "bluer" light is a result of both. Personally I like the look of 6500K. Which it the colour temperature of the sun at noon. But Water plays an important role here. Red and Green light in combination with Blue create white light. But water quickly strips the red and green wave lengths leaving blue light to penetrate further into the water.
So the theory is that if we heavily supplement out lighting with the blue spectrum more intensity will reach further depths. That is the theory. But in reality 18-24" water depth is a very shallow depth relative to a natural reef.
But it will in some way increase the light intensity at all depths.
The benefit of MH bulbs is even though you are getting a 2000K bulb it is still full spectrum meaning elements of red and green light exist.
This is the fundamental difference between VHO or PC lighting that have a very narrow band or light ie. a 1000K BLT only emits around 475 degrees Kalvin and nothing else.

More later have to go to dinner

J

 

Nice J that covers a lot.
Which bears to mind, what kind of 20k bulb did you buy?

[quote author=szogun link=board=General;num=1080937371;start=0#11 date=04/02/04 at 19:31:00]Now my question is will my corals grow slower under that bluish spectrum than they would under the 6500K?
[/quote]

From what I read, 6500k Iwasakis are suppose to be hard to beat for growth, so I would tend to think so. That said, there are high kelvin bulbs which have been rated with 'good' growth. So what J touched on is it is a trade off to have a more visually appealing bulb.

Why I suggested going with the 20k was to even out the light, if I had two different halides over my tank, well not my tank, but a longer tank, I would 'see' a difference whether it was there or not and it would drive me nuts. Could you see a difference between the two?

By the way, you said 5500k in your 1st post. I actually used to have one of those bulbs a long time ago and didn't like it.

 

I got the XM bulb from helolights $65

 

OK Guys I hope my new 20000K bulbs will keep my corals growing [smiley=hehe.gif]

Although, i have another question Do you think I have enough light? I mean even for the hard corals and clams?

Now I have 1 250W 20000K on one side, 1 175W 20000K on the other side, and one regular 48" 40W actinic fluorescent. I'm not thinking of adding any VHO actinic because the 2 MH 20000K give me the color I want.

So what you think is it enough? O and one more thing
The depth of my tank is 19" not counting the sand bad, and the bulbs are 12" over the water Thanks for all input. [smiley=yelrotflmao.gif]

 

Yeah, you can have anything with that light on a 75 if you place it right. You should be fine.

 

Thanks I'm happy to hear that