[GLLUG] OT: LED grow light

[Sean O'Malley]

I am sure this has been thought of before, but a traffic light out on my
way to work reminded me of it.

Given plants use mostly the red and blue spectrum. the exact frequencies
vary depending on species.

You might be able to get away with a red LED traffic light.

MOST cities already use these because of the long life and lower energy
costs. They use standard 120vac current and they are replaced 100-150 watt
halogens.


On Sun, 1 Mar 2009 charles at bityard.net wrote:

> On Sun, March 1, 2009 7:23 pm, Sean O'Malley wrote:
> > This is the one I saw from instructables that caught my eye.
> > http://www.instructables.com/id/high-power-LED-grow-lights-M.k2/
> >
> > Since it sort of combines hydroponics with led grow lights and the guy is
> > dirt cheap in his designs.  I saw a few kits online but most of the
> > small ones were sold out and they are quite pricey. I can't pay 100 bucks
> > for grow lights I will use maybe 2-3 months while germinating outdoor
> > plants. (my outdoor plant budget is 50 bucks a year.)
>
> You'll want to pay close attention to the datasheets when you buy the
> LEDs. A commenter noted in step 1 that you have to plan very carefully
> when using LEDs are grow lights. The bandwidth of LEDs is so narrow that
> it's difficult to adequately cover the wavelengths of light that plants
> absorb with only 2-3 types of LEDs.
>
> Although, it should be said that I know nothing of growing plants so maybe
> his design is "good enough." :)
>
> > I think I saw something where they had a backlog of orders for the leds. I
> > don't know how true that is or whether there is something else affecting
> > the market.
>
> I haven't heard of a shortage of high-power LEDs. It looks like you can
> get them on eBay for between $5-$10 each (including shipping).
>
> > The part that got me interested in LEDs was to replace the CF bulbs in my
> > house as the flicker irritates my eyes. (Slow refresh rates on crt
> > monitors does too.) They are more environmentally friendly as they don't
> > contain mercury like the CF bulbs do. However I havent seen them for much
> > less then 100 bucks a bulb.
>
> Yeah, LEDs aren't really up to replacing general-purpose lighting just
> yet. I've been toying with the idea of buying some white LEDs in bulk to
> make  under-cabinet lighting for the kitchen but I don't know that I'll
> ever have the time. (Also, my kitchen is too ugly right now to warrant
> additional illumination.)
>
>
> Charles
> --
> http://bityard.net
>
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