Depending on your setup and size of tank, I would say basic water movement from your main return pump if you have a sump or just a power head or two for sumpless tanks with some movement at the water surface for gas exchange. Skimmer would be good as it will help keep the water clean and also add oxygen to the water for the livestock. As far as lighting, tanks should be fine for awhile without lighting. The oceans have storms and clouds all the time and they survive just fine. If you have a heavy coral setup, then lighting will be a bit more important, but could be put on a reduced schedule.

Hopefully eveyone makes it through the storm ok. My grandparents are leaving Rockport in the morning with what they can gather and headed to higher ground here in SA.