Apparatus, including a carbonation chamber, comprising: a mixing and metering member, configured to respond to a fluid, including water, and an adjustable amount of gas, and configured to provide a mixture of the fluid and the gas, wherein a gas adjustment member, configured to receive the gas, including from a gas inlet, and to provide the adjustable amount of gas to the mixing and metering member, based at least partly on an adjustable axial relationship between the mixing and metering member and the gas adjustment member in order to control a desired carbonation level of the mixture, wherein the mixing and metering member comprises a metering orifice member having a first portion (12c 1) formed with a first set of orifices configured to allow a fluid, including water, to pass from a fluid inlet to a mixing chamber, and having a second portion (12c 2) configured so as to form an enclosed space or cavity (12c 3) therein, configured with a gas receiving part having a second set of orifices formed therein to allow a gas to pass from a gas inlet into the enclosed space or cavity (12c 3), and configured with a third set of orifices (12g 1, 12g 2) to allow the gas to pass from the enclosed space or cavity (12c 3) to the mixing chamber, including directly into the mixing chamber or via the first set of orifices into the mixing chamber; and the gas adjustment member is configured to receive the gas receiving part of the second portion (12c 2), and characterized in that it is also configured to be adjusted up or down the gas receiving part to control the amount of gas that passes to the mixing chamber and the carbonation level of the fluid. a mixing and metering member, configured to respond to a fluid, including water, and an adjustable amount of gas, and configured to provide a mixture of the fluid and the gas, wherein a gas adjustment member, configured to receive the gas, including from a gas inlet, and to provide the adjustable amount of gas to the mixing and metering member, based at least partly on an adjustable axial relationship between the mixing and metering member and the gas adjustment member in order to control a desired carbonation level of the mixture, wherein the mixing and metering member comprises a metering orifice member having a first portion (12c 1) formed with a first set of orifices configured to allow a fluid, including water, to pass from a fluid inlet to a mixing chamber, and having a second portion (12c 2) configured so as to form an enclosed space or cavity (12c 3) therein, configured with a gas receiving part having a second set of orifices formed therein to allow a gas to pass from a gas inlet into the enclosed space or cavity (12c 3), and configured with a third set of orifices (12g 1, 12g 2) to allow the gas to pass from the enclosed space or cavity (12c 3) to the mixing chamber, including directly into the mixing chamber or via the first set of orifices into the mixing chamber; and the gas adjustment member is configured to receive the gas receiving part of the second portion (12c 2), and characterized in that it is also configured to be adjusted up or down the gas receiving part to control the amount of gas that passes to the mixing chamber and the carbonation level of the fluid.