Metal Halide Q&A

Discussion in 'Metal Halide Aquarium Lighting' started by Dingo, Feb 16, 2010.

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  1. Night-Rida

    Night-Rida Finback Whale

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    I guess running a 14k-20k MH bulb alone would be enough blue spectrum that you wouldnt need actinics very much for growth..

    20k bulb at my LFS looks awesome alone without addt'l bulbs.. plenty of glow..
     
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  3. Dingo

    Dingo Giant Squid

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    the higher kelvin bulbs are actually counter productive. They are for aesthetics only. 10000K is by far the best type of bulb for growth because they produce the highest average intensity over a large range of wavelengths. (in the picture above, you can see this because the values for spectral irradiance are higher in 10K)
     
  4. steve wright

    steve wright Super Moderator

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    Thanks Dingo

    next question - Fiji purple T5s are often metioned as great for improving colours of SPS corals
    would supplementation of 10k MH with Fiji purple T5s be a better option than supplementing with actinic T5s?

    Steve
     
  5. Dingo

    Dingo Giant Squid

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    to better illustrate this we can compare a 10K to a 20K
    The 10K has much higher values for the output
    [​IMG]
    than the 20K
    [​IMG]
     
    Last edited: Feb 16, 2010
  6. Night-Rida

    Night-Rida Finback Whale

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    both picture/graphs are 10k :)
     
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  7. Dingo

    Dingo Giant Squid

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    I did wonder about this myself so I purchased a fiji purple to try it out... I can say that if you choose actinic supplementation, this bulb is a very smart choice! It combines some of the red and yellow wavelengths that are not usually seen in normal t5's and are generally weak in MH. IME it has brought amazing greens and pinks to my tank ;)
     
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  9. missionsix

    missionsix Super Moderator Staff Member

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    Forgive me if I'm way off base here but, these graphs are the same?
     
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  10. veedubshafer

    veedubshafer Banned

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    I am going to be running 400w MH's over a 29" deep tank. How far away should I keep the bulb from the water. The reflectors aren't going to be anything crazy just some DIY stuff.
     
  11. Dingo

    Dingo Giant Squid

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    fixed lol thanks
     
  12. Dingo

    Dingo Giant Squid

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    your PAR at the bottom will be fine for anything you want... The heat will be pretty significant so I would keep them higher. It is personal preference but I would recommend 10 inches, possibly more if you have issues. As jonjon stated earlier, fans will help a lot