A fluid preparation apparatus for a renal failure treatment is disclosed. In an example, the fluid preparation apparatus includes an inlet configured to receive water from a water source and a fluid line fluidly connected to the inlet. The apparatus also includes a pump fluidly connected to the fluid line. The pump is configured to pump concentrate from a concentrate container to mix with the water to form a fluid mixture. The apparatus further includes a sensor configured to measure a composition characteristic of the fluid mixture. Additionally, the apparatus includes a controller operably coupled to the pump, the sensor, and a valve. The controller is configured to receive a composition characteristic value from the sensor, and cause the valve to route the fluid mixture for the renal failure treatment when the composition characteristic value indicates that the fluid mixture is suitable for the renal failure treatment.