2016/03/11 The solution must be above the tank's indicator?

Why must I keep solution at the tank's level indicator? 
The solution level should always be maintained at the level indicator in the tank, with trays or beakers installed. The ultrasonic cleaning system is a 'tuned' system. Improper solution levels will change the characteristics of the environment, can affect the system frequency, decrease effectiveness, and potentially damage the cleaner. Maintaining the proper solution level provides optimum circulation of solution around parts, and protects heaters and transducers from overheating or stress.