Most important is the lights. Since you'll be upgrading, I would suggest LED
lights such as Taotronics. There is a lengthly LED
lighting thread which I think is in the getting started thread. Normally 1 unit per 2 feet length, but If that is a 7 ft tank, I'd see how many dividers it has (2 dividers=3 lights, 3 dividers = 4 lights). These lights will support anything you will want in the tank.
Water Quality is much more important in a Reef than a FO
tank. Nutrient export has to be 100%, so a quality skimmer as well as macro algae in the sump. Make sure your nitrates and phosphates are both 0 (you can do this while still running as a FO
) with no algae build-up in the tank.
Rocks, if you don't have any yet (you didn't say FOWLR
). You can slowly add them to the DT, or place them in a heated rubbermaid container with the right salt levels and cycle them seperate from the tank. This can take a few weeks.
Fish. Make sure any you have are compatable with reefs.
I think that's about it. Water quality good, upgrade lights and add corals.