The proprietary design of Black Berkey filtration and purification elements compensates for the incredibly small pore size by using an exponentially larger number of micro-pores in each element. This is why Black Berkey water filters produce approximately 8 times more water per hour than other competitive elements. Although a number of the surface pores can become clogged with contaminants, it is very difficult to submerge all of the pores and thus clog the filter. In the end, we may see a slowing of the filtration rate, but never a total clogging. If this happens, the filter can be cleaned by simply brushing the outside of the element with a ScotchBrite pad or toothbrush. This will remove particles that clog the surface pores of the filter. In conclusion, even though the filters have very fine micro-pores, the filter will not clog prematurely.