Life is full of choices: Paper or plastic? Boxers or briefs? Beach vacation or mountain vacation? If you're buying an aquarium, you have another choice: saltwater or freshwater? Consider the following before making a decision.
Your experience. The most important factor in making a choice is you. Maintaining a saltwater tank requires expertise. Sea World (home of Shamu) advises that "when setting up an aquarium for the first time, a freshwater aquarium is suggested."
Tank types. Freshwater and saltwater fish don't live in the same environments in the real world, nor do they live in the same tanks in the aquarium world. The setup for a saltwater tank can be more than two times the cost of the setup for a freshwater tank. Much of this increased cost is due to additional aquarium test kits and other equipment. Often, an aquarist will set up your saltwater tank to maximize fish beauty and color.
The fish. The fish are the focal piece of any aquarium. More colorful fish make their homes in saltwater. That doesn't mean, however, there aren't any colorful freshwater fish to enjoy. There just aren't as many. Saltwater fish cost more than their freshwater counterparts, especially if you live in noncoastal areas where shipping and handling is added to the cost.
Maintenance. Salt corrodes and can damage tank equipment. Changing water, the most common maintenance activity, requires considerably more work with a saltwater tank. Periodic, partial water changes suffice for freshwater tanks. Simply replace 10 percent to 15 percent of the tank water and replace it with filtered tap water and your tank remains clean. With a saltwater tank, the saltwater may need to be mixed up days before in a separate container.
Fish introduction. Saltwater fish are harder to introduce to their new environment than freshwater fish. Because saltwater fish are most likely coming from a wild environment, they need to be quarantined. It also may be difficult to get saltwater fish to eat aquarium food.
Conclusion. If you're an expert with ample resources and want the most colorful, vibrant fish available, go with saltwater. Most people, however, are better suited for freshwater aquariums.