Interesting numbers

Discussion in 'Reef Lighting' started by mikejrice, Oct 16, 2009.

to remove this notice and enjoy 3reef content with less ads. 3reef membership is free.

  1. mikejrice

    mikejrice 3reef Affiliate

    Joined:
    May 24, 2009
    Messages:
    5,926
    Location:
    Colorado
    Thinking about buying one, but I don't have all the different types of lighting to do a comparison anyway.
     
  2. Click Here!

  3. Av8Bluewater

    Av8Bluewater Giant Squid

    Joined:
    Aug 27, 2008
    Messages:
    3,401
    Location:
    Dallas
    You should get a PC light system and let us know how it goes. :)
     
    1 person likes this.
  4. mikejrice

    mikejrice 3reef Affiliate

    Joined:
    May 24, 2009
    Messages:
    5,926
    Location:
    Colorado
    lol I already have one over my frag tank. I have no intentions of ever running PC over my DT again. If nothing else I'll run halides just for the shimmer. I'm just the scientist type that likes to look into things. I never expected to find what I did.
     
  5. Dingo

    Dingo Giant Squid

    Joined:
    Aug 1, 2009
    Messages:
    4,767
    Location:
    New Freedom, PA
    A pc light emits the wavelenghts of mainly visible light and some infrared(not of interest in aquaria) as all mh produce a larger range of wavelengths in both the visible light and the ultraviolet spectrum... The ultrviolet specturum is used in photofluorescence of a lot of corals! The closest a pc can come is a 420 nm actinic and that is still weak in the uv range.
     
  6. Screwtape

    Screwtape Tonozukai Fairy Wrasse

    Joined:
    Sep 25, 2008
    Messages:
    2,289
    Space is quite a huge thing when you're trying to cram as much light over your tank as possible to keep high light coral. Considering most people's tanks, even with MH don't approach natural sunlight levels in shallow water where a lot of high light corals thrive, space is pretty key, and not something to be dismissed lightly.

    Also just to comment on the earlier statement that the levels compared with just bulb tests without reflectors. Part of the problem with PC is the way the bulb is shaped you can't create an extremely efficient reflector like you can with T5 and MH. The way the bulb bends you're always going to lose some light as the bulb is in effect lighting itself, not directing that energy appropriately downward into the tank so you're always going to be wasting energy no matter what.

    Testing the bulb only doesn't actually give you a realistic test of performance, it gives an OK "baseline" on what it's capable of but that's pretty much the minimum performance you should expect, not the theoretical maximum of how it can perform with good reflectors, cooling, and ballasts.

    Regarding PC vs T5, the T5's generally need to be replaced less often as well before their spectrums start to shift.
     
    1 person likes this.
  7. mikejrice

    mikejrice 3reef Affiliate

    Joined:
    May 24, 2009
    Messages:
    5,926
    Location:
    Colorado
    Check out these numbers again. It breaks the PUR color values down and they are still quite comparable.
     
  8. Click Here!

  9. mikejrice

    mikejrice 3reef Affiliate

    Joined:
    May 24, 2009
    Messages:
    5,926
    Location:
    Colorado
    While the reflectors could have negative effect to some unknown degree, I still only agree that space and cost of bulbs are the primary factors against PC lighting.
     
  10. Dingo

    Dingo Giant Squid

    Joined:
    Aug 1, 2009
    Messages:
    4,767
    Location:
    New Freedom, PA
    at whatever depth these were taken at you can see the micromoles * s^-1 are almost doubled in almost all the cases for mh though
     
  11. mikejrice

    mikejrice 3reef Affiliate

    Joined:
    May 24, 2009
    Messages:
    5,926
    Location:
    Colorado
    The MH is also a more efficient bulb that I picked from the list. There were MH on the list that were far less efficient than the PC bulb.

    MH put out 4.26 PUR Red uE/s/watt
    PC put out 5.74 PUR Red uE/s/watt
     
  12. Dingo

    Dingo Giant Squid

    Joined:
    Aug 1, 2009
    Messages:
    4,767
    Location:
    New Freedom, PA
    Most corals don't absord red at all... I Am in class rift now but I'll show you some literature in a few hours whn I get out. I work with sanjay joshi here at psu. He writes for advanced aquarist on mh bulbs