An apparatus and method for dispensing a discrete volume of fluid. The apparatus includes a pump operable in discrete cycles, a power source connected to the pump, and a controller connected to at least one of the pump and the power source. The controller is configured to vary the power provided from the power source to the pump during at least a portion of each discrete cycle based on characteristics of the pump and the fluid. For example, the controller may vary power by controlling the duration of the provision of power, or by controlling the amplitude of the power. Varying the power is intended to improve the accuracy of the discrete volume of fluid dispensed. Correspondingly, the method of dispensing a discrete volume of fluid includes receiving information pertaining to the fluid to be dispensed, and adjusting a provision of power to a pump based on the information. The method may include adjusting the duration of the provision of power, or adjusting the amplitude of the provision of power.