The present invention relates to modulators of cystic fibrosis transmembrane conductance regulator, compositions thereof, and methods therewith. In addition to a regular frequency, at least one higher frequency is possible, which is enabled in situations where a reader is known to be close to the chip. The top, trailing end of the filter receives a cylindrical insert that together with the imperforate bottom fitting insert helps hold the filter open as liquid fluid flows into it. Water is pumped from the tank into a trough of the filler unit via the supply line.