A method of aquaculture is applicable to a novel culture arrangement for diversified farming of generally deep sea fin fishes, shrimps, and shellfishes. A pre-manufactured enclosed cultivation tank is provided and air compressor facility is included for pressurization and oxygenation so as to make the interior of the cultivation tank a pressurized water environment of predetermined high pressure. A low pressure siphon tube is included for sucking and removing excrements from the cultivation tank and to realize water replacement in a natural manner thereby providing a deep sea mimicked clean cultivation environment. The drained water is subjected to multiple steps of filtration and purification for separating the excrements from the water and for purifying water to allow cyclic use of the water. An arrangement of multiple cultivation tanks allows for diversified and multi-species cultivation of fishery products and deep sea fishes.