A personal hydration system includes a control valve assembly including a valve body provided with a first inlet port, a second inlet port, and an outlet port provided with a delivery hose for dispensing at least fluid from the hydration bladder. The control valve assembly further includes a non-collapsible reservoir which holds an additive and is directly mounted via a rigid connection to the second inlet port of the valve body. A supply hose is connected between the hydration bladder and the first inlet port of the valve body. A valve core is rotatably mounted in the valve body to establish at least either a single flow condition of the liquid or a mixed flow condition of the liquid and the additive. In the mixed flow condition, the liquid from the hydration bladder freely flows through the valve core and is admitted into and circulated through the reservoir to produce a mixture of liquid and additive deliverable to the outlet port.