Abstract: An apparatus and method for treatment of fluid such as water with ozone. The apparatus comprises an ozonator for providing a gas containing ozone and an aspirator which mixes the gas with water to provide an ozone and water mixture having microbubbles of gas therein. The mixture is then circulated through an elongated treatment conduit having a length of between about 20 and about 40 feet and a diameter less than about 1 inch to allow the gaseous ozone to dissolve in the water. Throughout the length of the conduit the ozone oxidizes impurities in the water and provides water having a relatively high purity. In the method of the present invention a liquid such as water is mixed with ozone and the mixture is then circulated through an elongated treatment conduit to allow for dissolution of the ozone into the water and to provide purified water. The ozonator used to provide ozone is capable of providing a gas having at least about 1.