A saltwater tank requires quite a bit more upkeep than a freshwater tank. The salinity ( how much salt is in the water ) must be monitored and kept at a specific level, or your fish are likely to die. Water evaporates from the tank each day, which causes the salinity to rise, so freshwater, not saltwater, must be added on almost a daily basis to make up for the evaporation. Once a week or every other week, a 10% water change should be done on the tank as well. This involves removing 10% of the water from the tank, and adding newly mixed saltwater to the tank.

Tanks come in different sizes and shapes. The bigger the tank, the more fish you will be able to have (but you will also have to do bigger water changes). You can get a 'tall' tank or a 'short' tank. A 'tall' tank has more height than a 'short' tank, but can sometimes be harder to clean, as it can be difficult to reach the bottom of the tank.

There is also something called a 'nano' tank. These are miniature sized tanks that usually only contain one fish, and then some corals.

Lighting is one thing to consider. There are several different types of lights you can get for your tank.

Power Compacts - These are good for keeping fish, and some soft corals.

VHO- These are good for fish and soft corals and sps corals.

Metal Halides- These are the mercedes of lights. With these lights, you can pretty much grow any type of coral in your tank. If you plan on getting these lights...you'll want to make sure that if you plan on getting a canopy for your tank that you get one that quite tall, as these lights must sit about 10 inches over the water.

Refractometer: A refractometer measures the salinity (how much salt is in your water) of your tank. Yes, you could by a $5.00 plastic hydrometer.... but these are for the most part... crap. If you want to make sure your fish live, we strongly suggest popping the $70 for a refractometer.

Water Pump: The fish need movement in the water, so you'll need a pump to supply current. The pump size will depend on your tank size.

Protein Skimmer: Protein skimmers basically get uneaten food and fish poop out of the water. They will help keep your water quality up. If you don't plan on having many fish in your tank...you could possibly use a different filtration system such as a bio-wheel.

Live Rock and Live Sand are basically rock and sand from the ocean that have tons of little critters living in there. Sometimes live rock can have interesting hitchhikers such as sea urchins and star fish hiding in them. Live Rock and Live Sand can help keep the levels of bad components (nitrates and nitrites) down. It also gives your fish places to hide...

There are several different ways you can go with a tank.
Fish Only: just fish...no corals...no live rock...we kind of think this is boring..but some people like it... and some fish eat corals and cannot be kept with coral unless you don't mind them eating them.

Fish Only With Live Rock: fish and live rock.... no corals. Many people start out this way, then get corals when they begin to learn more about the hobby.

Fish,Live Rock, Corals: this adds corals into the mix.