[JoeHoetzl]

Looking for pre-wired LED's - Auto Parts store was my source - two nicely mounted White LED's at R&S (they come in blue, but I think white looks a little more natural, if natural at all).

Wired them to a radio shack 3-12v selectable (brightness control) powerblock.
Picked up a power socket so when I remove the cap I can quick disconnect the lines...

They look like this:
http://www.geocities.com/jhoetzl/tank/images/equipment/led_lighting1.jpg
http://www.geocities.com/jhoetzl/tank/images/equipment/led_lighting2.jpg

 

[JoeHoetzl]

What do they look like when on?

That turned out to be seemingly impossible to photograph with my camera.
My Canon powershot S10 just doesn't seem to be up to the task, and believe me, I tried every mode I could think of, it just isn't bright enough for the little lens on that camera. I tried manual spot metered, macro'd, "slow shutter", different zooms and camera position, you name the setting on that camera, I tried it.

Even tried a few with some ambient lighting behind the tank and it just washes out the led's.

If someone knows how to get it to do a longer exposure, I'd love to know how. Without a better camera, a picture is out of the question in my opinion.

They aren't that dim to my eye, but even pushing the input to the LED's to 12v, I can't get them to show up.