A dissolved ozone delivery system comprising; a generator assembly for producing gaseous ozone, a container for holding a liquid, the liquid suitable for receiving the gaseous ozone produced by the ozone generator to form an ozonated liquid with ozone dissolved therein, a conduit for delivering gaseous ozone from the ozone generator into the liquid in the container, and a container sealing device, whereby: a. the generator assembly comprises a generator for converting oxygen to ozone and provide an ozone containing gas stream, and means for delivering an oxygen containing gas stream to the generator, b. the conduit for transferring the ozone containing gas stream exiting the generator to the interior of the container, the conduit having a first end attached to a gas exit port on the generator and a second end located below an upper surface of the liquid in the container, the second end having a gas diffuser attached thereto for distributing the gaseous ozone into the liquid to create a solution with ozone dissolved therein, c. characterised in that the container sealing device comprises a closure assembly for attachment to an opening in the container to provide a pressure tight seal, the conduit passing through the closure assembly in a leak proof manner d. wherein the closure assembly comprises an upper portion and a lower portion, the lower portion separable from the upper portion with the lower portion remaining secured to the container opening and the upper portion remaining attached to the ozone generator such that, when assembled, ozone produced in the generator passes there through in a leak proof manner and into the liquid in the container, and when separated the upper portion remains attached to the ozone generator, the lower portion when separated from the upper portion being configured to receive an ozonated liquid dispensing system. a. the generator assembly comprises a generator for converting oxygen to ozone and provide an ozone containing gas stream, and means for delivering an oxygen containing gas stream to the generator, b. the conduit for transferring the ozone containing gas stream exiting the generator to the interior of the container, the conduit having a first end attached to a gas exit port on the generator and a second end located below an upper surface of the liquid in the container, the second end having a gas diffuser attached thereto for distributing the gaseous ozone into the liquid to create a solution with ozone dissolved therein, c. characterised in that the container sealing device comprises a closure assembly for attachment to an opening in the container to provide a pressure tight seal, the conduit passing through the closure assembly in a leak proof manner d. wherein the closure assembly comprises an upper portion and a lower portion, the lower portion separable from the upper portion with the lower portion remaining secured to the container opening and the upper portion remaining attached to the ozone generator such that, when assembled, ozone produced in the generator passes there through in a leak proof manner and into the liquid in the container, and when separated the upper portion remains attached to the ozone generator, the lower portion when separated from the upper portion being configured to receive an ozonated liquid dispensing system.