BigAl's slow chronicle . . .

[Ratpack]

Originally Posted by tbittner

You mean we could/should all be using the standard "daylight" MH's that you can buy at Lowes?

Ohhh, someone answer this before I head to Lowes at lunch!!!!

[BigAl07]

Originally Posted by Anselth

Well, by dimming the blue you'd be dimming the intensity somewhat (I think)...not sure if it would be enough to make a difference, but I'm not too familiar with the Solaris. Where's Jack when you need him?

Still in bed or on the road traveling most likely!!!

[AQTCJAK]

in bed was correct

[BigAl07]

Morning Jack! We have some "conversation" going about the Solaris and it's "K" ratings . . .

[AQTCJAK]

The Sun, for instance, has an effective photosphere temperature of 5778 K

Color temperature is a characteristic of visible light that has important applications in photography, videography, publishing and other fields. The color temperature of a light source is determined by comparing its chromaticity with a theoretical, heated black-body radiator. The temperature (in kelvin) at which the heated black-body radiator matches the color of the light source is that source's color temperature; for a black body source, it is directly related to Planck's law


Planck's law - Wikipedia, the free encyclopedia

[mps9506]

Hey guys.
I find this article by Sanjya Joshi very informative on the basics of the effects of wavelength AND intensity on coral growth.
Remember the quantity of light a coral gets and the spectral quality are two different but important aspects of lighting!
Aquarium Frontiers On-Line: Feature

[vdituri]

Thank you for the article Mike.
Great read!

[BigAl07]

I'm lost Well kind of!! I'm gonna go to bed and sleep on it

[AQTCJAK]

lost about?

[BigAl07]

I thought I had a thorough understanding of "K" value and how it affected coral growth and how it's percieved in our eyes but now after reading more I'm lost. So just having a higher "K" value doesn't mean a lower PAR value at all. So K to Par isn't proportional at all.

[AQTCJAK]

correct you got it man

[Jason25]

AL, maybe this will help you or confuse you more but like jack said all light is measured from a "black body" and is measured in Kelvin which this is definition of The kelvin (K) temperature scale is an extension of the degree Celsius scale down to absolute zero, a hypothetical temperature characterized by a complete absence of heat energy. Now what makes that up is the wave length of a particular spectrum of light these are called nanometers or NM which is what your actinics are measured in. Just because we can not see a particular spectrum of light does not mean that it does not exist or our corals do not use it. Nanometers are what give off the color of light for example a 460nm wavelength is what makes the blue we see from actinics. I believe that somewhere around 580nm is where our eyes can no longer see the light and this is in the UV range.

[BigAl07]

Thanks Jason. I do get where the "Kelvin" comes from as it's a "Color Temp" relative to Absolute Zero. But what I can not grasp is par to "K" relationship. Maybe I'm over analyzing this one (not the first time that's for sure).

Either way my next bulbs will be a Higher "K" just because I like blue/crisper look over the yellow look.

[KodiakBear]

PAR and K are totally different entities. K measures the whole spectrum of electromagnetic wavelengths in light and relates to the balance between the different wavelengths present. Higher number = more blue, lower = more red. PAR measures only the photosynthetic wave lengths (400-700nm) and measures the intensity of those wavelengths.
What's also important in PAR is understanding the absorption characteristics of your critters. A light might have a high PAR rating, but be worthless to you tank if it's all in the higher wavelengths (red light) Most corals are insensitive to red and benefit primarily from the blue end of the spectrum. Nuisance algaes love red light though!
Here's an interesting study on light in a reef off French Polynesia: http://www.int-res.com/articles/meps/131/m131p245.pdf

ps. I use the word 'interesting' rather liberally.

[BigAl07]

Thanks for the input! So what's the "drawback" to higher "K" light as far as coral growth then? It seems many people have noted that Higher "K" bulbs may not provide as much coral growth as lower "K" but maybe they aren't comparing apples to apples in that sense. Can you have bulbs of various "K" rating with similar PAR?