The Georgia Aquarium holds the record for the largest aquarium in the US

The Georgia Aquarium in Atlanta is the largest aquarium in the United States by total water volume. It holds 11 million gallons of water across its exhibits and is home to thousands of animals, including whale sharks, beluga whales, and manta rays. The facility opened in 2005 and remains the standard against which other major US aquariums are measured.

Size in aquariums is measured by water volume rather than floor space, because a tall tank with deep water holds far more than a wide, shallow one. The Georgia Aquarium's 11 million gallons is roughly equivalent to 17 Olympic swimming pools. This volume allows the facility to house large marine animals that require substantial space and specific water conditions.

Key Takeaways

  • The Georgia Aquarium in Atlanta holds 11 million gallons of water, making it the largest in the United States.
  • Aquarium size is measured by total water volume, not by building footprint or number of exhibits.
  • Several other major US aquariums—including those in Monterey, California and Oahu, Hawaii—hold between 750,000 and 3.2 million gallons each.
  • The largest aquariums require specialized systems to maintain water temperature, salinity, and oxygen levels for their animal populations.

Other major aquariums and their water volumes

Several other aquariums in the United States rank among the largest by volume, though none match the Georgia Aquarium's scale. The Monterey Bay Aquarium in California holds approximately 750,000 gallons and is known for its kelp forest exhibit and sea otter populations. The Aquarium of the Pacific in Long Beach, California contains roughly 12.9 million gallons, which actually exceeds the Georgia Aquarium—but this figure includes water in behind-the-scenes systems and animal care areas, not just public exhibits.

The Oahu Aquarium (officially the Waikiki Aquarium) in Hawaii holds around 500,000 gallons. The Shedd Aquarium in Chicago contains approximately 5 million gallons across its exhibits. These facilities vary in their focus: some specialize in local marine ecosystems, while others feature animals from around the world. The difference in volume often reflects the types of animals on display—facilities housing large pelagic fish or marine mammals require significantly more water than those focused on smaller species or coral reef systems.

Why aquarium size matters for animal welfare

Water volume directly affects the health and behavior of aquarium animals. Large marine animals like whale sharks and manta rays require substantial swimming space and consistent water conditions. A whale shark in the Georgia Aquarium's main tank has room to move in patterns closer to what it would experience in the ocean, though no aquarium can fully replicate open-water conditions.

Larger water volumes are also easier to maintain at stable temperatures and chemical levels. A small tank's water temperature can shift rapidly if heating or cooling systems fail, stressing or harming animals. The Georgia Aquarium's 11 million gallons acts as a buffer—temperature and salinity changes happen more gradually, giving backup systems time to respond. This stability is one reason why larger facilities can house a greater diversity of species and support longer-term animal health.

How aquariums measure and report their size

Aquariums report water volume in gallons, but the definition of what counts toward that total varies. Some facilities count only water in public viewing tanks, while others include water in behind-the-scenes filtration systems, holding tanks, and animal care areas. This difference can make direct comparisons tricky—two aquariums might claim similar sizes but have very different amounts of water visible to visitors.

The Georgia Aquarium's 11 million gallons figure includes all water in the facility, both public and private. When comparing aquariums, it helps to ask whether the reported volume includes only exhibit tanks or the entire system. Facilities that are transparent about this distinction make it easier to understand how they rank against competitors and what visitors will actually see.

The systems required to maintain massive aquariums

Operating an 11-million-gallon aquarium requires specialized equipment that most people never see. The facility needs powerful pumps to circulate water through filtration systems continuously, removing waste and maintaining oxygen levels. Temperature control systems keep water at the precise range each species requires—tropical fish need warmer water than cold-water species, and some exhibits maintain different temperatures simultaneously.

Salinity systems maintain the salt content of saltwater exhibits, which must match ocean conditions for the animals to thrive. The Georgia Aquarium also uses UV sterilization, protein skimmers, and biological filtration to keep water clean without harming the animals living in it. These systems run 24 hours a day, seven days a week, with backup power generators in case of outages. The cost of operating and maintaining this infrastructure is substantial, which is one reason why only a handful of facilities in the US can support aquariums of this scale.

How the Georgia Aquarium compares to aquariums worldwide

While the Georgia Aquarium is the largest in the United States, it is not the largest in the world. The Chimelong Ocean Kingdom in China holds approximately 12.9 million gallons, and several other international facilities exceed the Georgia Aquarium's volume. However, the Georgia Aquarium remains one of the most visited and well-known aquariums globally, attracting over 10 million visitors since it opened.

The distinction between "largest in the US" and "largest in the world" matters because different countries have different standards for animal care, exhibit design, and reporting. The Georgia Aquarium's size is significant within the context of American facilities and the regulatory environment they operate in, even if larger aquariums exist elsewhere.

Frequently Asked Questions

Does the Georgia Aquarium have the biggest tank in the world?

No. The Georgia Aquarium's main tank holds 6.3 million gallons, but other facilities worldwide have larger individual tanks. The Chimelong Ocean Kingdom in China and some other international aquariums have tanks that exceed this size. The Georgia Aquarium's distinction is that its total facility volume—all tanks combined—is the largest in the US.

How many animals live in the Georgia Aquarium?

The Georgia Aquarium houses over 11,000 animals representing more than 700 species. The exact number changes as animals are born, transferred to other facilities, or pass away. The facility works with other aquariums and conservation organizations to manage breeding programs and animal populations.

Can you visit the Georgia Aquarium?

Yes, the Georgia Aquarium is open to the public in Atlanta. Admission costs vary by age and whether you purchase tickets in advance or at the door. The facility also offers special experiences like behind-the-scenes tours and animal encounters, which have separate fees.

How much does it cost to build an aquarium this large?

The Georgia Aquarium cost approximately $290 million to build when it opened in 2005. This figure reflects construction, equipment, animal acquisition, and initial staffing. Costs for a facility of this scale vary based on location, design, and the types of animals housed, but large public aquariums typically require hundreds of millions of dollars in capital investment.

What is the difference between the Georgia Aquarium and the Aquarium of the Pacific?

Both are major US aquariums, but they differ in focus and design. The Georgia Aquarium specializes in large marine animals like whale sharks and beluga whales. The Aquarium of the Pacific in Long Beach emphasizes Pacific Ocean ecosystems and local species. The Georgia Aquarium's public exhibits hold roughly 6.3 million gallons, while the Aquarium of the Pacific's public exhibits hold around 3.2 million gallons.