Device and method for controlling deposit formation

The invention describes a method for controlling deposit (60) formation in a liquid (5) bearing system (100) comprising a main system (1) and a subsystem (2), wherein a liquid (5) is transported inside the main system (1) and/or the subsystem (2), the method comprising the step of altering a property of the liquid (5) inside the subsystem (2) such that it differs from the property of the liquid (5) inside the main system (1) in a manner that deposit (60) formation inside the subsystem (2) is more promoted than inside the main system (1). The subsystem (2) may be designed as a bypass. The deposit (60) formation may be detected inside the subsystem (2), for example by means of ultrasound, wherein an ultrasonic signal is emitted and a reflected ultrasonic signal is detected. A device for controlling deposit is also claimed.