Why Berkey Filters Get Mold – And How To Prevent It – Water Purification Guide_how to bypass ge rpwfe water filter

Why Berkey Filters Get Mold – And How To Prevent ItWritten by Theresa Orr in Mold,Uncategorized

Mold is a common problem in homes, especially with appliances that use water. Since Berkey Filter systems have water in them almost all the time, you may be wondering: do Berkey Filters get moldy?

Berkey Filters may get moldy, especially in the upper chamber with the unpurified water. Mold infestations can also establish in the lower chamber where water can sit for long periods of time.Infrequent cleaning and old or clogged filters can also lead to mold growths in Berkey filtration devices.

It’s totally normal for such filtration devices to get mold here and there. Not only can you remove the mold from the Berkey Filter easily by following our step-by-step guide, but with little care, prevent it from occurring again.

Where Does the Mold Occur on Berkey Filters?

Berkey Filters are relatively simple devices with not so many components, unlike, say, whole house water filters. However, you should inspect the following parts of the system to see whether it has any mold growth or not.

Filter Housing or Water Chambers

Berkey Filter systems are essentially the same in design but differ in water capacity, size, and the number of filters. For all models, including the largest Crown Berkey, the water chambers made of stainless steel are the most likely to get mold on their inner surfaces.

This can also happen with the plastic one, the Berkey Light. Normally, plastic doesn’t provide any nutrients for the mold to thrive on, but the water might.

Mold occurs more commonly in the upper chamber where you add the impure water. However, don’t be surprised if you find mold growth in the lower chamber as well with the clean, filtered water.

It can form on any part of the surface, especially the base of the filter housing and corners.

Remember that mold thrives in humidity and dark, both of which are readily available inside the Berkey water filter systems.

Black Berkey Filter Elements

Black Berkey Filter - Berkey Black Filter Replacement Filters (BB9-2)

The Black Berkey Elements(link to replacement) inside the Berkey Filters are self-sterilizing. This means the filters prevent the growth of any bacteria or fungus on their surface. So as such, the Black filter elements will not get any mold.

If the mold exists in the filter housing/chamber, you may want to clean the filter anyway and prime it. (More on that later)


Berkey Stainless Steel Spigot

The Berkey spigot(link to replacement) that goes on the stainless steel Berkey models (all models except Berkey Light and Go) may be prone to mold as well.

Although highly unlikely, as it’s made of quality food-grade stainless steel, mold may emerge on the outer surface of it or on the metal or plastic washers.

What Does Mold Look Like On Berkey Filters?

It’s important to know exactly what mold may look like. It rarely occurs on stainless steel, but when it does, you’ll start to see tiny black spots. These spots may also have a dark greenish or brownish color, but mostly black.

If you have the plastic models, the appearance would be similar, except the mold may also be white in color.

How to Remove Mold From Berkey Filters: Step-by-Step Guide

If your Berkey Filter system has developed mold growth anywhere, it is possible to clean it out.

Here’s how you do it:

Step 1: Empty Out the Chambers

Regardless of the model you have, empty out both the chambers if you haven’t already. Just turn on the spigot and collect the water in a bucket or let if flow directly down the drain.

Step 2: Remove the Filters

Remove the Black Berkey Filter Elements (all of them). If you’re also using the Fluoride filters, remove those too.

Step 3: Scrub the Filters

Inspect whether the filters need replacement. Your filters don’t really get mold on them, but if they are still in working condition, they do deserve some cleaning.

Take an abrasive pad or a soft toothbrush and gently scrub the outer surface of the filters. Now, reprime the filter once (fill with water directly from your faucet) to flush out any old water in it.

Step 4: Clean the Chambers

If you’re dealing with mold in your Berkey Filter system, it’s likely that it’s present on the sides of the chambers or filter housings. Remember, mold grows on surfaces but not in the water itself. There are several cleaning agents that can be used to remove its growth from the housing’s surface.

Let’s talk about each:


Washing the moldy surface with warm water containing a few drops of bleach can get rid of the mold. However, it’s not the best method as bleach can be abrasive.

If you do resort to using bleach, make sure you choose one without any artificial additives (such as fragrances or coloring).

Use a sponge or brush to scrub off the mold with this warm water and bleach solution. Then rinse the housing at least twice.

White Vinegar

White vinegar is a natural cleaning agent that can kill bacteria and get rid of mold from the housing surface or spigot.

Either soak the whole housing in white vinegar or use a spray bottle containing white vinegar. Make sure you cover both the interior and exterior of the two chambers. Let them sit for 15 to 30 minutes while the vinegar does its job.

Afterwards, rinse the housings thoroughly and if the vinegar has left any stains, you can even use a mild soapy solution to get them off easily.

Baking Soda

Baking soda is another great natural cleaner that doesn’t just remove mold but also gets rid of the mold smell.

Mix one quarter to one tablespoon of baking soda (depending on the size of the housing) with water in a spray bottle. Spray the solution all over the moldy and non-moldy parts of the system.

Let it sit for about 10 minutes and then scrub gently with a medium-hard scrubbing brush. Scrubbing will get rid of the mold as well as any stains on the surface.

Step 5: Inspect and Clean the Spigot

The spigot (tap) attached to the bottom chamber will also probably be moldy.

Use any of the above mold removal methods. If washers have too much mold or a lot of wear and tear, you may want to consider replacing them.

Step 6: Let Everything Dry

Once everything is washed and rinsed, let them air dry.

Step 7: Reassemble the Berkey Filter

Now, with all the mold gone and your Berkey Filter clean, you can go ahead and put together the device once again, and fill it with water.

How to Prevent Mold in Berkey Filters?

You know how they say: prevention is better than cure. The same applies to water filter systems.

You can prevent the growth of mold in the filter housings by cleaning them periodically. It would also help if you replace the filters on time.

If the filters are old and become clogged, it will take forever for the water to collect in the bottom chamber. Also, impurities will start to make their way through the filter, increasing the chances of mold formation.

It’s also important to not leave the water in the chambers for too long. If you’re going somewhere and you know you won’t be home for a few days to weeks, make sure to empty it out, dry the housings/chambers, and store the system properly. 

How Long Can You Leave Water in a Berkey?

It is advised not to leave water in a Berkey for longer than four days. If you think you’ll be away from home for longer than that, make sure to empty out the lower chamber. Also, when you refill it, discard the water purified and collected in the lower chamber in the first minute.

This applies to all the models of Berkey Filters.

Do Berkey Filters Expire?

Unused Berkey filters don’t expire as they typically have an indefinite shelf life.

However, once they are used, their lifespan must be respected. For instance, the quintessential Black Berkey Filters last for about 3,000 gallons per filter.

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