Hi, I have mixer taps and the hot water, but not the cold water, was spraying when it came out. I took off the tap head to clean the filter and this piece fell out of the tap. Looking into the tap, there is a plastic tube, but there is no place to screw it back into. The tap is better, but not flowing perfectly. What is the piece and is it necessary? I have also tried the hand over the tap method, turning both taps on to remove an airlock, in case it was that. It's not spraying as much, but the flow is not consistent, so wondering how vital this piece is? Any ideas?