LED

LED stands for Light Emitting Diode. This is a diode that has been altered so that it's primary function is to emit light.

What is a Diode?
A diode is an electronic component that allows current to flow in only one direction.

Pros of LED Lighting

 * Efficient. Uses less electricity and produces less heat than other lamps.
 * Polarised point type light source. (Makes the water "shimmer")
 * Long life. Typically ~40,000 hours with only 20% output fall.

Cons of LED Lighting

 * Narrow colour spectrum.
 * Takes many of them to produce sufficient light output.
 * Good LEDs are expensive.