First off welcome. Maintaining a sw
aquarium isn't much different than fw
. What equipment you'll need depends a little on tank size and set up you want but some basics are ro
water, flow device, rock for bio filtration (either live or base) , a skimmer is nice to have but not necessary depending on what size tank, and then you have lighting which there are to many options to list and this also depends on tank size. Fish and coral in the same tank is no problem as long as you do your research and get reef safe fish, there are also lots if cool inverts you can add. IMO
the 2 most important things for starting and maintaining a reef are research and patience.