Abstract: A clothes washing machine comprises a water container and a washing tub disposed in the water container to form a space therebetween for containing wash water. A tourmaline ceramic coating is applied to an outer bottom surface of the washing tub or to an inner surface of the water container for reacting with the wash water to form hydroxyl ions therein which reduce surface tension of the water. An ultrasonic vibrator is mounted on the water container across from the coating to generate waves in the water to accelerate the reaction between the coating and wash water. Alternatively, the tourmaline ceramic coating could be applied to an agitator disposed in the washing tub.