Abstract: A water pump for bodies of water such as ponds, aquariums, or fountains containing suspended particles has a housing with a pump housing part provided with an intake opening and an exit opening, in which housing part an impeller with a shaft is rotatably supported, and a motor housing part in which an electric motor is received. As an improvement, an electronically commutated motor is used and the pump has a power input as well as power and control electronics for the motor having an operating state detection device with speed detection, processor and data storage device. The processor can control an interrupt switch between the power input and the motor. In the data storage device certain characteristic lines in regard to normal operating states can be stored.