This project is about a fully functional water level controller using Arduino and Cayenne. The cayenne App displays the level of water in the tank and switches the motor ON when the water level goes below a predetermined level. The circuit automatically switches the motor OFF when the tank is full. The circuit also monitors the level of water in the sump tank (source tank). If the level in side the sump tank is low, the motor will not be switched ON and this protects the motor from dry running. A beep sound is generated when the level in the sump tank is low or if there is any fault with the sensors.
This may be the sensor that was being used. I have used this before for water sensing and also soil moisture sensing. Cheap and works sufficiently for my prototyping needs!
I think you are right. Especially if using a ‘cheap’ version of sensor. For long term use, I think would be good to invest in a high quality sensor, maybe like this one.