Kelvin and Spectrum's

I just put this link on another thread. However, it fits the bill for this thread too.

Advanced Aquarist's Online Magazine - Feature Article: Poor Man's Spectrometer: Estimating Lamp Spectral Quality for Less Than $30

 

Great read.
I had no idea you could get a decent spectrometer for that cheap.

Also the spectral signature of the Iwasaki 6500k bulb shows me why that bulb is still around.

Thanks Curt.

 

I need to revive this thread because I have a question.

example(all hypothetical):

a person buys a T5 fixture and needs bulbs for it. the tank is 48x24x24. they want to keep anything. What K bulbs should they buy. I get confused with the 420, 460, 03 blue, true blue, 10k, 12k, 14k, 20k. What is the best set up for a reef? I know watts plays a part but what I'm asking is which is better for the reef, not adding watts to the equation.

 

is there a general guideline for what corals are at what depths.like soft corals 10-30ft,
something like that

 

aaaaaaaaaaahhhhhhh that makes sense with the 10,14 & 20!!!!!!!!!!!!!!

so 10k bulbs are good for acros and higher placed corals? or do they live deeper rin the ocean....I think this is gonna be like that ole can-o-worms!

yeah still wondering about the 420, 460,

 

Yes, this is a can-o-worms and that is why you're confused. People unfortunately think of SPS as a species and they all have the same requirements. That's not true at all. In fact, only this hobby has the word SPS....it's not a real designation used by science.

For instance, if I had a Montipora capricornis, and Montipora digitata, and a Montipora danae, I would light each of them very differently. Sure, they are all considered SPS by the hobby and they are all Montipora, but their care needs are very different. Same thing goes for Acropora.....there are a whole lot of different species in the Acropora Genus. They don't all have the same care needs. There are deepwater Acro's as well as Acro's that live on the surface and tend to have very strong skeletons. There are acro's that do fine on the patch reefs and tend to have thinner skeletons but more leeway in terms of nutrients. There are acro's that tend to do best on the leeward side of the reef proper and they are more fragile. Many (not all) deepwaters have thinner skeletons and do better with more blue light. Basically, you need to know what you have.

This is called Coral Reef Zonation. Dr. Warren did a fairly good write-up of this a number of years ago. OZ REEF - Coral Reef Zonation

Tangster is right. As depth increases, the shorter wavelengths start disappearing. Remember ROY G. BIV from school? The deeper you go, the more spectrums disappear. Infra-red goes first, Red, Orange, Yellow, Green, Blue, Indigo, Violet.....then Ultra-Violet. That is why the ocean looks more blue the deeper you go. (It's also why the dust in the atmosphere makes the sky look blue).

The higher the K, the bluer the spectrum (but at the same time, the more wattage required for the "typical" reef aquarium). That's why you don't see 150W Radiums...they are typically 250's or 400's. However, if you drop your temperature (Kelvin), you can find lower wattage bulbs.

420's are true actinic.....460's are daylight. Some actinic and some light in a different spectrum.

Heck, after typing all this out, I'm not sure if I made it more clear or more confusing.

 

Thanks everyone --this has helped. I also am a little confused about actinic light, exactly what does it do?

 

Most pigments in coral tissue are called pocilloporin and are catagorized as either Brightly Colored Low Fluorescent Pocilloporins or as Highly Fluorescent Pocilloporins. Highly Fluorescent Pocilloporin pigments have the ability to absorb light with a specific wavelength and then fluoresce or emit this light into a different wavelength.

Basically they make our corals flouresce and look bright and colorful. Advanced Aquarist's Online Magazine - Feature Article: Coral Coloration: Fluorescence: Part 1

Here's some awesome flourescence pictures
Magnificent Fluorescence! Aquaristic Perspectives by Anthony Calfo - Reefkeeping.com