In cleaning objects using an ultrasonic cleaner, water is not enough. Water can remove contaminants attached to objects. However, sticky and slimy contaminants cannot be removed by plain water. To completely remove all contaminants, an ultrasonic cleaning solution has to be used. This type of cleaning solution is especially made for ultrasonic cleaners. An ultrasonic cleaning solution has elements that can remove even the most stubborn impurity. It also has substances that make the surface tension of the solution low. These substances are called surfactants. Surfactants help produce cavitation bubbles.