How long do Berkey PF-2™ water filters last?

A pair of Berkey® PF-2™ water filters is effective for treating approximately 3,800 litres of water and usable for up to 1 year.

In order to know when the filters need to be changed, a simple calculation detailed below can be used to determine which first limit comes first.

- Assuming the use of a Big Berkey® model equipped with 2 Black Berkey® filters, filled once a day, the calculation is as follows

3800 / 7.3 / 365 = 1.42 years >> in this case the annual limit comes first and you must change your PF-2 filters after one year.

- If you do 1 and a half filtration per day, you adapt the above calculation: 3800 / 7.3x1.5 / 365 = 0.95 years or 11 and a half months

- If you make 1 filtration per day with a Royal Berkey®, the calculation is as follows: 3800 / 11 / 365 = 0.94 or 11 and a half months

This calculation is to be adapted according to the model used and the frequency of refills.

You can also apply this formula to Black Berkey® filters, starting from the theoretical filtration capacity of 22,700 litres.