+ Reply to Thread
Page 1 of 4 1234 LastLast
Results 1 to 10 of 32

Thread: Screen lighting

  1. #1
    kcress's Avatar
    Join Date
    Nov 2008
    Location
    Santa Cruz, California, USA
    Posts
    458

    Screen lighting

    Light Color.

    What is the best color? Do we actually know? The white CFLs seem to work pretty well, but I have seen red and blue bantered about. Anyone know exactly which red or blue?

  2. #2
    Administrator
    Join Date
    Oct 2008
    Location
    Salt Lake City, Utah, USA
    Posts
    10,566

    Re: Screen lighting

    Most seem to work well. My acrylic uses 3000K on one side, and 6500K on other. I have trouble telling the difference.

  3. #3

    Join Date
    Oct 2008
    Location
    Canterbury, UK
    Posts
    426

    Re: Screen lighting

    I personally found 3000k lights pretty poor and have had much better results from 6500k lights, however the 6500k bulbs themselves seemed to produce more light (same wattage, different style, different manufacturer).
    In general I've notice much more algae growth in various tanks under 20000k MH bulbs than under lots of lower colour temp tubes, even if they produce similar amounts of light, so again it would suggest better growth from higher colour temps.

  4. #4

    Join Date
    Oct 2008
    Location
    Canterbury, UK
    Posts
    426

    Re: Screen lighting

    Hmm, had a thought.
    I think the reason they use red and blue LEDs for growing plants must be because they're aiming it only at green leaves, so the green light is reflected and not absorbed, therefore wasted. Higher colour temp bulbs are producing slightly better growth as they have more blue in the light.
    I would also guess that with red/blue LEDs you'll probably find that certain different coloured algae doesn't grow as well, e.g. the darker browns, as they would absorb more of the spectrum.
    However, it would be a complete waste getting bulbs (non-LED) that are coated with a colour as the coating simply absorbs the other colours, I believe LEDs actually produce the right colour spectrum without needing colourings (could be wrong, as red LEDs are in red plastic most of the time).

  5. #5
    Administrator
    Join Date
    Oct 2008
    Location
    Salt Lake City, Utah, USA
    Posts
    10,566

    Re: Screen lighting

    Actually all algae and plants use primarily red and blue only, since that's what chlorophyll A and chlorophyll B use. They don't use green, and they don't use "white". That's why plant-grow LEDs are only reds and blues. The product the algae and plants grow, however, looks green.

  6. #6
    kcress's Avatar
    Join Date
    Nov 2008
    Location
    Santa Cruz, California, USA
    Posts
    458

    Re: Screen lighting

    Ah the A/B thing. All those higher temp bulbs do put out way more blue. I had just never really seen blue lights used in growing applications of plants. The blue and red seemed strange to me since I would think one or the other not both Maybe the A/B thing.

    Of course the reason I ask is because making a LED panel for a screen allows one to pick specific colors of about any shade with only certain colors utterly unavailable. I'd rather use just the color desired by the algae of interest.

    Perhaps a test will be needed. <Sigh>

  7. #7

    Join Date
    Oct 2008
    Location
    Canterbury, UK
    Posts
    426

    Re: Screen lighting

    That was my point Santa
    White light is a mixture of RGB (red green blue), so the green is wasted as it's reflected and not absorbed, but as not all algae is green, and some is technically bacteria, I guess they don't all use chlorophyll.
    Still want to find out if red LEDs actually emit red light without the red plastic around them, if so, they're just as inefficient as white LEDs for this purpose.

  8. #8
    kcress's Avatar
    Join Date
    Nov 2008
    Location
    Santa Cruz, California, USA
    Posts
    458

    Re: Screen lighting

    Quote Originally Posted by worley
    Still want to find out if red LEDs actually emit red light without the red plastic around them, if so, they're just as inefficient as white LEDs for this purpose.
    Sorry now I understand your question.

    All LEDs with the exception of white put out the color you see. The only reason some are in colored plastic is so they themselves light up when energized. Colored ones are used to "indicate" as apposed to "illuminate".

  9. #9

    Re: Screen lighting

    Been doing a bunch of research on this topic. Here is an excellent and very detailed article on bulb comparison for planted aquaria: http://www.aquabotanic.com/lightcompare.htm. Apparently regular daylight fluorescents from phillips at 5000k are the best, but basically, the brighter the better. (And Lumens aren't necessarily the best indicator of light energy output).

  10. #10
    kcress's Avatar
    Join Date
    Nov 2008
    Location
    Santa Cruz, California, USA
    Posts
    458

    Re: Screen lighting

    cvermeulen; That was exactly what I was looking for!

    Many thanks!

+ Reply to Thread
Page 1 of 4 1234 LastLast

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts