Here we go:
http://www.reefcentral.com/forums/sh...91#post8179491

Power Compacts
Similar to Compact Fluorescents, these have a wide variety of sizes, wattages, shapes, colors, etc. They are often what beginning aquarists are told to use.

Abbreviation: PC
Starter: Usually a Ballast located off of the bulb
Heat: Moderate. These can become quite hot and can burn you. But, their heat is still pretty minimal.
Depth: About 18"-20" before their usefulness fades
Height: About 1"-4" off the water surface
Lifespan: About 8 moths to 1 year.
Common Livestock: All. Generally Soft Corals, LPS, Zoanthidae, and Corallimorphians, but occassionally SPS and Clams
Sample Lighting
Length: 3ft Power Compact
Wattage: 96 Watts
Output: 2,250 Lumens
Cost: About $10-$30 per bulb

T5
This is also a relatively new lighting system on the market and has proven to have great success. The name is a little misleading though. While it does state the size of the bulb, T5, it doesn't state that T5's are almost always T5 High Output. To utilize these bulbs effectively, adding a parabolic reflector is almost essential. It helps focus the light enough to make it comparable to metal halides.

Abbreviation: T5, T5HO
Starter: Ballast
Heat: Minimal. It does produce heat, but not much. Bulbs can usually be touched after they have been on for several hours.
Depth: Quite Deep. About 24"-30" before it starts to get without reflectors. With reflectors, depths of greater than 36" have been reported.
Height: Usually inches off the water. Occassionally up to 6" off the water.
Lifespan: About one year.
Common Livestock: All. Many people are having great success. Occassionally some of the animals that like dimmer lighting are caught in the crossfire to appease other corals.
Sample Lighting
Length: 4ft T5HO Fluorescent Bulb with individual Parabolic Reflector
Wattage: 54 Watts
Output: 5,000 Lumens (focused light)
Cost: $15-$25 USD