www.guardianonline.co.uk Some billionaires exercise their philanthropic bent by building museums or symphony halls. The legacy of Bernard Marcus, who runs an American DIY chain, will be the world's largest fish tank, almost 10 times the size of the London Aquarium.

The Georgia Aquarium, due to open in Atlanta in November, will have 5m gallons of water (almost 19m litres) and more than 100,000 fish. It will be home to two white beluga whales, giant groupers and octopuses.

The main attraction will be two whale sharks, the world's largest fish, which can grow to more than 40 feet. The sharks, Ralph and Norton, are adolescents and currently 13ft and 16ft long. They were transported from Taiwan in a plane with aquatic life-support systems.

Asked in an interview why he had decided to build the aquarium, Mr Marcus said: "I like big fish, OK?"

The aquarium, he added, is so well designed that fish will prefer it to the ocean. "This is like going to the Ritz Carlton," he said. "If you ask them, do they want to go back to the ocean, you know what they would say: 'Are you crazy?'"

Mr Marcus made his fortune from the retail chain Home Depot, which he founded with his business partner, Arthur Blank, as single store in Atlanta in 1978. The pair built it into a chain of 1,900 stores with annual sales of $73bn (أ‚آ£41bn). Mr Blank prefers birds to fish: he bought the Atlanta Falcons American football team in 2002 for $545m (أ‚آ£305m).

The Georgia Aquarium is being funded entirely with private money and will be run by a non-profit organisation. Mr Marcus said he is committed to conservation and the aquarium will have the largest research facilities in the world.

Atlanta hopes the Aquarium, built alongside a convention centre, will become a hub for tourists. In 2007, Coca-Cola, will open its museum nearby.