LED lighting is now the only lighting on my 2g tank; Hemianthus
Callitrichoides and Hydrocotyle verticillata (pennywort I think) are
pearling like crazy roughly 1 hr after lights on.
Here's the basics - I'm using an old computer AT powersupply to feed
12v (thanks for the idea listers- a few of you mentioned it). I built
3 LED arrays, 2 arrays to a board - the boards are 3/4" wide and
roughly 8" long to sit nicely on the rim of the 2g. Positive power is
fed on the right, negative to the left - LEDs and resistors sit in
between.
The boards themselves were a Radio shack special - the local store
had a clearout on the IC board etching kits. Once etched, cut drilled
and assembled, the boards were sealed with 3m 5 minute epoxy, roughly
1/8" on top and bottom - totally waterproof.
After redneck testing the first board - it was way too blue, so on my
mission to radio shack, I picked up 4 red LEDs too, and a
potentiometer. I built an X shaped array, with the potentiometer so I
can dial it up for a lot of red, or dim it down for aesthetics.
I ended up using 12 white LEDs to light the tank - largely due to the
small distance from light to substrate (8" or so). The red array
rests on the white. The tank is MUCH brighter with the LEDs than it
was with the 2 13w PC's that I was running over it.
The 10g is the next test subject - I'm trying to find some LEDs with
a very wide beam for this one to handle the overall lighting;
possibly these - http://www.ledsupply.com/l1-0-w5th70-1.html Then
use some smaller arrays of more focused light to put light where its
really needed.
FWIW - ebay seems to be the best/cheapest place to find LED lights;
they seem to go for half what they're sold for on retail sites. But
at the same time - I haven't found any wider angle white LEDs there.