Do Berkey Filters Need to Be Primed? How Often & When to Re-Prime

By Jeff Wise Published: January 26, 2026 Updated: February 18, 2026

If you own a Berkey water filter system, you may be wondering: do Berkey filters need to be primed every time, or is priming a one-time step?

The short answer is yes — all Berkey filters must be primed, but how often depends on how they’re used, stored, and maintained.

This guide explains when priming is required, how often to re-prime, and how priming affects water flow, taste, and performance for Black Berkey filters, Phoenix Berkey replacement filters, and PF-2 fluoride filters.

What Does "Priming" a Berkey Filter Mean?

Priming is the process of fully saturating a Berkey filter's internal media with water before use.

Berkey filters use dense, activated carbon-based filtration. Until the microscopic pores are completely filled with water, air pockets can restrict flow and reduce performance.

According to filtration experts, activated carbon filters must be properly pre-wetted to function as intended and allow consistent water flow through the media.

This principle is widely recognized in the water filtration industry, including by organizations like the Water Quality Association (WQA).

Do All Berkey Filters Need to Be Primed?

Yes. All current Berkey-compatible filters require priming before use, including:

Black Berkey® filters (standard filters included with Berkey systems)
Phoenix Berkey replacement filters
PF-2 fluoride & arsenic reduction filters

Even though these filters serve different purposes, they all rely on tightly packed filtration media that must be fully saturated with water to work properly.

How Often Do Berkey Filters Need to Be Primed?

In normal daily use, Berkey filters typically only need to be primed once. However, there are several situations where re-priming is necessary.

You should do this if:

The filters were allowed to dry out
The system was stored or unused for an extended period
You notice a sudden drop in flow rate
Water taste changes unexpectedly
New PF-2 fluoride filters were installed

If any of these apply, re-priming can often restore proper performance without replacing the filters.

If re-priming no longer improves performance, you may need to assess how to know if Berkey filters are bad and whether replacement is the better solution.

Do PF-2 Fluoride Filters Need to Be Primed?

Yes. PF-2 fluoride filters also require priming before use.

Because these filters use a different reduction media than standard carbon filters, proper priming is especially important to ensure consistent water flow and effective fluoride reduction.

Whenever PF-2 filters are newly installed, replaced, or allowed to dry out, they should be primed according to manufacturer guidelines.

Improper priming can also affect water clarity. If your filtered water looks hazy or milky, see our guide on why Berkey water can appear cloudy and how to fix it.

What Happens If You Don't Prime Berkey Filters?

Skipping priming — or failing to re-prime when needed — can lead to several common issues:

Extremely slow filtration or no flow at all
Uneven water flow between filters
Air bubbles trapped in the filter media
Changes in taste or odor

Many users experiencing these problems assume their filters are defective, when in reality, they simply need to be re-primed.

If taste is your main concern, see our detailed troubleshooting guide: Why Does My Berkey Water Taste Bad? 7 Causes & How to Fix It.

Priming vs. Cleaning: What's the Difference?

These two serve different purposes.

Priming removes air from the filter media, while cleaning removes surface buildup that can slow filtration over time.

If your system has been in regular use but the flow rate has slowed, cleaning may help. If the system was unused or dried out, priming is usually the fix.

For flow-related issues, this guide can help pinpoint the cause: Why Is My Berkey Flow Rate So Slow? 7 Common Causes & How to Fix It Fast.