This may be caused by the following.
Too much high activity carbon has passed down the tube to the black cartridge after the tap has been turned on.
Helpful Hint: Put a 25 mm spacer under the continuous filter, at the front where the hose exits to the continuous filter.
This will tilt the container back, and ensure that the High Activity Carbon settles to the back of the filter.
This will avoid any carbon from settling over the outlet to the filter cartridge which could block it.
It is important to let most of the High Activity Carbon settle before opening the tap and letting the spirit flow through to the filter cartridge. This takes 24 hours. If you open the valve too soon then too much carbon may flow down the tube and clog the filter paper making the process go much slower.
The Filter Cartridge may have been overfilled with Finishing Carbon.
As the carbon reacts with the spirit it expands and heats up. Always leave a 10 mm gap for expansion.
Temperature: The filter system operates best at normal room temperature.
As the spirit cools down it becomes thicker. As a result, in winter the whole process slows down.
Try heating your spirit before adding it to the reservior or putting the Continuous Filter in a warm place.
Too many filter papers or the wrong type of filter paper.
A dirty or clogged tube, tap or cartridge.
The whole Continuous Filter should be rinsed thoroughly after every use.
Impatience: Remember that the Continuous Filter is removing unwanted impurities from your spirit.
Trying to speed things up too much will effect the quality of your spirit.