No. The positions of the two are not interchangeable and they do not have the same role. They are complementary. When the Berkey® PF-2™ water filters are installed, the water flows first from the upper chamber through the Black Berkey® purification elements, then into the Berkey PF-2™ filters and finally into the lower chamber.

The former have a purification role by removing all harmful elements from the water while the latter specialize in retaining fluoride and arsenic.