well I went to the aquarium store and bought two 25 pound bags (a bit over kill) instead, I mean i think I can invest 20 bucks to a substrate I will have for a hella long time.
Sati - Moonlights are used for a number of purposes... but I mainly used them for the fish to be able to see somewhat in the dark. Its good for fish mainly because the water isn't always pitch black, but more importantly is the fish getting spooked by bumbing into other fish. Fish can;t really see red or blue light, but can make out objects with these lights. Reef people use them and claim that it helps corals and the such, and as a bonus it helps the fish in the same way I ahve described. Not only does it help fish but the tank looks spectacular all times of the day, it also stops other people from asking to turn on the aquarium light at night "only for a couple minutes" which stress the fish, just like turning out the lights and of all the sudden it gets dark for the fish.
There are two routes you can go into making one (which I highly suggest and you'll see why...). One is by using LEDs (light emitting diodes) which are VERY efficient, very cheap, and provide whats called "spotlight lighting". Basically the entire tank can still be seen with these lights but there are points in the tank where it is more lighted than others. This helps create the "ripple effect" when the water's surface (for those of you who use
HOB filters) is disturbed... you can see the cool ripples int he tank. With this set up some electrictian knowledge is needed, like what and how to hook up the set up with transistors to get the right voltage, etc.
http://www.csd.net/~cgadd/aqua/art_nightlight.htm
http://www.kaotica.com/frag/
diy/moonlight/
The other route would be to use Cold Cathode tubes. I chose this route because it is a lot cleaner and easier to do, plus I wanted even lighting. These are cheap to get on ebay, which is what I did. Basically it is a mini-fluorescent tube that, like the LEDs, will be hooked up to whats called an inverter (I guess you could say its like a transistor) which then goes to an adapter (which both set ups need). Its really easy to attach to the underside of a canopy, but doesn;t last nearly as long as do the LEDs... they last about 15,000 hours - 30,000 hours, while LEDs last about 100,000 hours! 8O
If you have any questions I provided two links for the LED part of it, if you have questions about the cathode set up, ask away!