When to Replace Your Berkey Filter

One of the first things that you think about when you buy anything is “How long is this going to last me?” It’s no different with a Berkey water filter. Although the polished 304 stainless steel filter housing could last indefinitely, the Black Berkey filter elements at the heart of the Berkey water purification system do indeed need to be replaced periodically. Just how periodically the filter elements need to be replaced is something that varies from case to case. Read on to learn how to determine Berkey lifespan for you and your family.

When to replace black berkey filters

Calculating Filter Lifespan

When you pull up the specifications for the Black Berkey filter element, the stated lifespan is 3,000 gallons per element. Of course, nobody thinks in gallons. We think in days, weeks, and months. To convert this 3,000 gallon figure into actual replacement period, we have to do a little math.

First, make the best guess you can at how much water you will run through your filter, on average, each day. Let’s imagine you estimated 5 gallons of filtered water per day.

Next, you need to know how many Black Berkey filter elements you will have in your purification system. Filter elements are sold in sets of 2, so most people will have either 2 or 4 elements in their system. For bigger needs, Berkey sells some larger units that can accommodate 6 or even 8 elements. The number of filter elements you choose, times 3,000 will give you the filter lifespan in gallons.

So, supposing you choose a set of 2 filter elements:

2 x 3,000 = 6,000 gallons filter lifespan.

Now that you know the filter lifespan in gallons, you divide that number by the number of gallons you expect to use per day. In our example this is 5 gallons, so:

6,000 ➗ 5 = 1,200 days (a little over 3 years)

If you wanted to write this out as a simple equation, it would look something like this:

number of filters 3,000 gallons used per day = filter lifespan (in days)

Typical Scenarios

As we have just observed, filter lifespan depends on demand, so let’s look at some typical scenarios to get a feel for the longevity of our filters. A single person would come in at the low end of the demand scale, so would be likely to choose a smaller model like the Travel Berkey. Such a customer might fill the upper chamber once in the evening to have purified water ready in the morning for making coffee and filling a few reusable water bottles, then fill it again before heading out to work to have some delicious water to sip on throughout the evening. Let’s set this at about 2 gallons a day. At that rate, a pair of Black Berkey elements is going to last you 8 years!

Moving up to a couple with double the drinking water needs and perhaps some extra water needed for cooking, the Big Berkey water filter seems about right. We can peg this at about 4 ½ to 5 gallons a day. With a 2 filter setup, this would come out to the same 3 years as in the example above. With 4 filters, you can double that and go 6 years between replacements.

On the larger end of the spectrum would be a large family with plenty of kids. In this case, we would suggest a larger unit like the Royal, Imperial, or even Crown Berkey to accommodate lots of thirsty kids, making hot and cold drinks, cooking, and perhaps even some water for dishes. For this example, let’s picture an Imperial Berkey with 6 filters putting out 10 gallons of water per day. This arrangement will get you almost 5 years.

The Red Dye Test

This test is the simplest, most reliable way to know whether your filter is still purifying water like it should. Artificial food dye, specifically only red dye, perfectly simulates the kind of contaminants Berkey water filters are designed to remove. If the filter removes red food coloring, you can rest assured that it is removing anything on the long list of contaminants that Berkey filters can handle. If any red color gets through, you know that the filter elements are getting past their useful life, or are not installed correctly, allowing red dye to pass through. The nice thing about this test is that you can perform it at any time during the life of the filter. If you are concerned that you may not have installed the element’s mounting hardware properly or that the element may have been damaged in some way, you can perform this test and remove all doubt.

To perform the test, just pour water colored with Mccormick's red food coloring into the upper chamber (1 tsp per gallon). If the water that collects in the lower chamber is tinged with red at all, it is time to replace your filter elements. Read more specific instructions on performing the red dye test.

Important things to note about the Red Dye Test:

  1. 1. Always remove Fluoride Filter before running the red dye test.
  2. 2. Always pre-mix the food coloring, do not drop coloring on filters.
  3. 3. Always use artificial Red Food coloring.
  4. 4. Always make sure washers and wingnuts are properly installed for an accurate test.

Alternative Method: Observing Flow Rate

Inevitably, the tiny pores on the outside of your filter element are going to get clogged by contaminants, that will slow the flow rate down considerably. The good news is that the Black Berkey filter element is designed to be cleaned periodically. After removing the filter element from the housing and giving it a light scrubbing with water alone, the flow rate should return to normal. However, as the filter element nears the end of its useful life, cleaning the filter will restore less and less flow rate. This is a sign that it is time to change filter elements.

The cleaning itself is simple. Basically, you remove the filter element and scrub it with a 3M Scotch Brite pad under running water. Read more on cleaning Berkey filter elements.

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