Kelvin and Spectrum's

Discussion in 'Reef Lighting' started by geekdafied, Sep 23, 2007.

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  1. inwall75

    inwall75 Giant Squid

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  3. Matt Rogers

    Matt Rogers Kingfish Staff Member

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  4. cuttingras

    cuttingras Starving Artist :)

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    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.
     
  5. missionsix

    missionsix Super Moderator Staff Member

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    The actinic part can be confusing. Basically, it it's the spectrum that helps with photosynthesis. Technically it has to do with chlorphyll activation and a happy medium I believe is around 460. Not really sure with the actinic. I've never actually sat and read about it. Tangster has explained it to me before a long time ago. You've actually inspired me to figure it out. With MH or K it's simply compared to ocean depth and what/where your corals are found(depths) and do best in. For instance, 10k simulates depths of 10-30 ft(roughly), 14k 30-60ft. and 20k 60-90ft.

    Without getting to technical.
     
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  6. sostoudt

    sostoudt Giant Squid

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

    cuttingras Starving Artist :)

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

    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,
     
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  9. missionsix

    missionsix Super Moderator Staff Member

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    Maybe geek will chime in and explain the optimal use of actinic spectrum and the difference in nm. My eyes are starting to hurt searching the web trying to find something in "english". And his chart is cool in regards to k ratings. Kinda the same as I explained but, a little different.
     
  10. inwall75

    inwall75 Giant Squid

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    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.
     
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  11. 1st time

    1st time Purple Spiny Lobster

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    Thanks everyone --this has helped. I also am a little confused about actinic light, exactly what does it do?
     
  12. inwall75

    inwall75 Giant Squid

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    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