I have a 1000L tank and installed the gauge as per instructions. When the tank is being emptied the gauge works perectly. However when the tank is being filled, the gauge will stop well before the tank is completely full. When the tank is ompletely filled up the gauge still does not read FULL, stuck above the halfway mark. I simply hit the side of the tank with my hand which causes a vibration, and as a result of the vibration I hear the string reeling quickly, as if the string was stuck and then the gauge reads FULL.