beckysamotis,
Like so much else in the salt water hobby, the straight answer to your question is........it depends.
It primarily depends upon what corals you want to keep and how much money you want to/can spend. It also depends upon how you want your tank to look and how handy you are.
Corals are going to have low, medium, or high light intensity requirements. "Watts per gallon" is often used as a "rule of thumb" for the intensity ratings. Low=up to 3 or 4 watts/gallon; Medium=4 to 6 or 7, and High=8 and above.
The light fixtures that will provide the higher intensities are Power Compacts, Very High Output flourescents, and Metal Halide. The MH's are the most intense and are often recommended for corals that require very high intensity lighting.
there have been lots of debates about which is best......I'm not sure I've ever seen conclusinve evidence that one type is "best".
I have a 45 gallon tank.....similar in size/depth to yours. I knew I wanted to upgrade my lights from the Normal Flourescents I had. I did alot of reading and comparing prices. I also knew I was not going to build a hood myself and that I like the bluish tint of actinic lights. I checked a number of different web sites for lights and decided to buy a Hamilton hood.....175 watt/10,000K MH and 2 95 watts VHO actinics, with fans. I' ve got over 8 watts per gallon and just love the look of my tank. Downside was the whole thing was about $500. I guess you can get the picture......you spend less if you can do things yourself.
You can probably get alot of additional info by doing a search on this board for "lights" or "lighting". If you want the web sites I looked at to compare fixtures, let me know and I'll send them to you.
Jim
