I noticed that the PF-4 elements also remove MTBE and heavy metals. Should I use these with my Black Berkey purification elements?
No, the PF2’s are used in conjunction with the Black Berkey purification elements and the PF-4 elements are used in conjunction with the ceramic filters in the Big Berkey. The Black Berkey elements remove MTBE and reduce heavy metals whereas the ceramic filters do not therefore; we incorporated MTBE and heavy metals reduction capabilities into the PF-4 elements.