OK, loved Michael Paletta's The New Marine Aquarium, but his section on lighting is brief. Have a FOWLR tank that I hope to eventually turn into a Reef Tank (I know, some people feel I should make this decision upfront, others seem to rec waiting for my tank to be established). Can someone explain the difference in the lighting. Currently have a basic two bulb 32W X2 K-Lighting strips. My tank is 48X18X24 (90 Gallons). What are actinic lights? Neccesary for corals? What are T5s HOs. Just more powerful versions of what I have? Lunar LCDs? Are they neccesary? What's an actinic bulb? What about 50/50 bulbs? Looked at bulbs in my local aquarium store and they had 40W 50/50 bulbs? 2 adequate for a 90 gallon tank (I assume no if I plan to add corals). 4Watts per gallon rule? Helpful? Outdated?