Long but Interesting read

Discussion in 'Lighting' started by FransSny, 1 Jul 2009.

  1. FransSny

    FransSny

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  3. viper357

    viper357 Admin MASA Contributor

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    This article mentions a few times that blue (true actinic) light is important and the deeper your tank is the higher kelvin rating lights you need, interesting. This is the 3rd or 4th article I have read that says actinic light is required for coral growth, I always thought it was purely for aesthetic reasons, to make the water colour look better and to make the coral colours look better, yet it seems that true actinic globes are a necessity over a coral tank to promote coral growth.

     
  4. viper357

    viper357 Admin MASA Contributor

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    Which means that not only should we concentrate on buying top quality MH's or T5's but we also need to look into the best quality actinic tubes and not just the "cheapest blue light to make the tank look good".
     
  5. FransSny

    FransSny Thread Starter

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    Interesting comment Viper, to be honest I thing we all look at actinic from a aesthetics point of view.

    i must also mention that I have not been able to find another article to confirm all the facts / figures given in this one
     
  6. viper357

    viper357 Admin MASA Contributor

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  7. FransSny

    FransSny Thread Starter

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    Thanx Viper, the lighting issue still remains a bit of a mystery to me :p
     
  8. viper357

    viper357 Admin MASA Contributor

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    Me too, I've currently got 6500K MH's and 2 x 39w true actinic tubes to try and promote coral growth, but I think in a years time I will just put on normal 10000K or 14000K MH's, too much of an information overload on all these lights :p I'll just stick to what makes the tank look good.:)
     
  9. Annoying

    Annoying

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    I know this is a dumb question but does actanic lights have a kelvin reading... I never see it on the globes!
     
  10. Manic

    Manic Moderator

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    True actinics are in the 40 000K+ region... I think
     
  11. FransSny

    FransSny Thread Starter

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    20 000 K...also not sure :p
     
  12. Sentari

    Sentari

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    Interesting article thanks!
     
  13. Jaco Schoeman

    Jaco Schoeman MASA Contributor

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    Hey Guys, I think I might have the answer for you. This question also came up a week or two ago at my LFS when me and my salesman discussed my new tanks lights. I will be going with 4x 39W T5 (geisemann aqua blue + 15000K) and one 150W MH @ +22000K (geisemann)

    I asked whether 4x 39W T5's would be enough to keep SPS, as the +22000K MH is actinic, and does not contribute. So he said that the blue wavelenght, being suck a long wavelenght (compared to red) penetrates deeper, that is why the ocean is so blue down there... So what happens is, that the red high frequense light, gets pushed down by the lower wavelength blue (thus piggy backing on it as such) and thus the "whiter" light gets carried down along with the blue - reaching your corals.

    Again, this is not visible to the eye, but the PAR / PUR reading of the red spectrum goes all the way down with the blue. So it is in actual fact better to have the "punch" of the MH in blue, and supplement with white, as the white PAR and PUR then gets transported down with the blue...

    Does this make sense at all? Tried to explain it to my best ability...

    See below spectrum / wavelength information:


    Color
    Red 780 - 622

    Orange 622 - 597

    Yellow 597 - 577

    Green 577 - 492

    Blue 492 - 455

    Violet 455 - 390


    Wavelength (nm)

    The electromagnetic and sound specta and their use for communication

    [​IMG]
     
  14. Jaco Schoeman

    Jaco Schoeman MASA Contributor

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    Oh, and wrt the Kalvin reading of actinic - this is from the Geisemann website:

    Powerchrome Pure Actinic T5 : light colour: actinic - peak 421 nm
    Powerchrome Actinic Plus T5: light colour: deep blue 22.000 K
    Megachrome Blue Metal Halide: colour temperature : over 21.000 Kelvin
     
  15. viper357

    viper357 Admin MASA Contributor

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    Have they got a Kelvin rating for that tube?
     
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