Setting up a 30 gallon saltwater tank is an exciting endeavor that can provide you with years of enjoyment observing the underwater world. Before beginning, there are several things to consider and components to purchase in order to set up a successful aquarium. First, decide on the size and shape of aquarium you would like as this will determine what type of filtration system, lighting, and other accessories you need. You’ll need a stand or cabinet to support your aquarium. Consider how much space it will take up before making your decision. Next, buy a quality protein skimmer for efficient removal of organic waste from the water column and opt for mechanical filter media such as filter floss or sponges for additional biological filtration. Choose high-quality lighting which provides enough light intensity without generating too much heat; LED lights are energy efficient and ideal for reef tanks because they do not produce too much heat but generate plenty of light needed by corals to grow properly. Lastly, select substrate (gravel/sand) that has been specifically designed for marine aquaria which is necessary in order to maintain healthy conditions within the tank. With these components in hand plus live rock, heater if necessary depending on temperature requirements (i.e., tropical fish versus coldwater), thermometer/hydrometer combo unit(s) etc., setting up your 30 gallon saltwater tank should be relatively straightforward!