[SpaceProgram] Fwd: Space Farmers: LEDs As Key To NASA's Permanent Lunar Life Support - Forbes

[Stuart Young]

On 6 September 2012 12:14, cole santos <cksantos85 at gmail.com> wrote:

> @paul Supposedly it only works around a peak of 300nm with no effect
> within 50nm above and below. If you can find cheap leds in that spectrum
> you will be a millionaire in the waste water treatment industry they need
> just under 300nm for uv sterilizers, which is the major power consumer on
> treatment plants. Standard is florescent.
>
> @Mate I agree some plants absorb some light more than others, but in
> general you need blue and red. There are two basic chlorophyll types, A
> and B, and each has a red and blue adsorption peak. A is around 430
> (blue/violet) and 660 (deep red) while B is around 460 (blue) and 630 (red).
>  http://www.biologie.uni-hamburg.de/b-online/e24/3.htm Green/yellow is
> mostly useless. The thing with leds is they produce a very tight band of
> wavelength and plants only respond to a tight band of red/blue so you can
> buy led lighting and get screwed. Marine fish tanks get algae blooms with
> 660nm so I think that would be a good place to start with tests on algae.
> Plant growers seem to be using 630nm. But 630's are brighter than 660's of
> the same power output so it could just be a power issue.
>
> Here's some info i got on fish tank forum. (They seem to be the only guys
> trying to grow algae (marine) with leds, outside of academia behind pay
> walls.
>
> "One other interesting result that someone posted was that they were
> running a scrubber with an array of 6 3W 660 reds for about 6 months, and
> when they added one 455 blue LED to the mix, the growth changed
> dramatically, not so much in bulk but in form; the algae 'roots' where it
> was attached to the screen/substrate became substantially stronger (harder
> to scrape the algae off) and the algae strands thenselves became thicker.
> This suggests that the blue component does not so much contribute to
> overall growth as it does to some other strengthening factor."
>
> Supposedly a and b are for absorbing light at different times of day.... I
> dunno, but I do agree that the field is ripe for hackerspace exploitation.
>

This might be useful reading:

http://lib.tkk.fi/Diss/2008/isbn9789512295029/

There are LED based plant lighting systems out there, but they're all
horribly expensive, mainly from what tends to be the UV component (but in
some cases just cos they can).

-- 
Stuart Young (aka Cefiar)
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