lighting are very powerful flourecents that need stronger ballasts (Ballasts allow the lights to run at their wattage. one tube = about 100 watts (im noy sure here)
is the most powerful type of light that can mimic natrual sunlight also creates a pleasing shimmering effect. one bulb can = 400watts
Actinic refers to a blue light that stimulates coral growth, it is ussually created by some kind of tube light. Also creates a sunrise sunset affect when used with other lights
flourcent are your basic 20 watt bulbs that come with a tank they are not powerful and have varied spectrums.
Reefs require strong intense lighting to mimic natrual sunlight so corals can use the light and grow properly. Some corals prefer more light than others.
lighting for fish isn't as much of a concern they can acclimate tos most lighting situation.
Another option is Power Compact flourescents, they are rated at 65, 96, and 55 watts, they ususally are your best bang for your buck and work for soft, and LPS
corals. as long as there is enough of them. If you plan on having a thriving reef with a good mix of corals look into MH
combos with VHO