No, Does Berkey Remove Magnesium? Understanding How It Works

December 17, 2025 •

3 min read

According to Berkey, its Black Berkey purification elements are specifically designed to retain beneficial minerals like magnesium, rather than removing them from your water. This functionality is central to the system's design and is a key factor distinguishing it from other filtration methods that strip water of all dissolved solids.

Quick Summary

The Berkey system is engineered to purify water without stripping away essential, healthy minerals such as magnesium, calcium, and potassium. It achieves this through a selective process of ion exchange and adsorption that targets harmful contaminants while allowing beneficial ionic minerals to pass through to the lower chamber.

Key Points

Magnesium is retained: Berkey filters do not remove magnesium and other beneficial ionic minerals, which is a key feature of the filtration system.
Selective filtration: The Black Berkey elements use a process of adsorption and ion exchange that targets harmful contaminants while allowing healthy minerals to pass through.
Not a water softener: Since Berkey does not remove calcium or magnesium, it will not soften hard water.
Hard water maintenance: Users with hard water may experience slower flow rates due to mineral buildup and should clean their filters regularly.
TDS test results: Because Berkey retains beneficial minerals, a TDS meter will show a similar reading for water before and after filtration, indicating the presence of these healthy minerals.
Healthy hydration: Retaining essential minerals like magnesium contributes to the taste and health benefits of Berkey-filtered water.

Understanding Berkey's Unique Filtration Process

Many people assume that a high-quality water filter must remove everything from the water, but this isn't always the case. The Berkey purification system operates on a principle of selective filtration. Instead of indiscriminately removing all dissolved solids, the proprietary media within the Black Berkey elements targets a wide array of harmful contaminants while intentionally leaving beneficial minerals in the water. This process is different from water softening systems, which actively exchange mineral ions for sodium ions, thereby reducing hardness.

The Science Behind How Berkey Retains Minerals

The Black Berkey elements use a unique combination of microfiltration, adsorption, and ion exchange to achieve their purification. This multi-stage process is what allows for the distinction between removing contaminants and retaining minerals.

Ionic Attraction: The filter media has a complex structure with specific charged sites. Through ion exchange, it attracts and binds to undesirable 'bad' minerals and heavy metals, such as lead and aluminum, that have a specific ionic charge.
Beneficial Mineral Repulsion: Conversely, the media's charge does not attract beneficial 'good' ionic minerals like magnesium, calcium, and potassium, which have a different charge. As a result, these minerals are not absorbed and pass through the elements, remaining in the final purified water.
TDS Test Results: A simple TDS (Total Dissolved Solids) test can demonstrate this. Since beneficial minerals contribute to a water's TDS reading, the reading will be approximately the same before and after filtration with a Berkey system, assuming the source water is not contaminated with heavy metals.

Hard Water and Berkey Maintenance

While Berkey retains minerals like magnesium, it does not soften water. Hard water, which is rich in calcium and magnesium, can sometimes affect filter performance. These minerals can accumulate on the exterior of the Black Berkey elements, creating a film that can slow down the flow rate over time.

To maintain optimal flow with hard water:

Monitor the flow rate regularly. If it slows significantly, it may be time for a filter cleaning.
Clean the Black Berkey elements by scrubbing the surface with a Scotch-Brite pad under running water.
In areas with extremely hard water, using a pre-filter or periodically bypassing a water softener for drinking water can help reduce mineral buildup.

Berkey Mineral Removal vs. Other Systems

To fully appreciate Berkey's approach, it helps to compare its mineral handling with other popular water treatment methods. Different technologies have different effects on the mineral content of your water.


Feature	Berkey Gravity Filter (Black Berkey)	Reverse Osmosis (RO) System	Water Softener (Ion Exchange)
Removes Magnesium?	No, retains beneficial ionic minerals.	Yes, removes nearly all dissolved solids.	Yes, exchanges magnesium/calcium for sodium.
Water Taste	Often preferred, tastes more natural due to mineral content.	Flat or bland taste due to lack of minerals.	Varies, can taste salty depending on setup.
Beneficial Minerals	Intentionally retained.	Indiscriminately removed.	Replaced with sodium.
Mechanism	Adsorption and selective ion exchange.	Semi-permeable membrane pressure.	Ion exchange resin beads.
Purpose	Purification while preserving healthy mineral content.	Extreme water purification.	Reducing water hardness.

The Benefits of Retaining Magnesium

Magnesium is an essential mineral that plays a vital role in over 300 biochemical reactions in the body, including nerve function, muscle contraction, and maintaining a healthy heart rhythm. By retaining this and other minerals, the Berkey system provides not just purified water, but water that contributes to your overall nutritional intake. For those who choose to use reverse osmosis or distillation, adding trace mineral drops is often recommended to compensate for the loss of these important electrolytes. A Berkey system avoids this extra step.

Conclusion

The question "Does Berkey remove magnesium?" is answered with a clear 'no.' The Berkey purification system is designed with a deliberate purpose: to remove harmful contaminants while leaving behind the beneficial minerals, including magnesium, that our bodies need. This selective filtration process, which relies on a proprietary blend of media and ionic attraction, is a key selling point for those who prefer to keep their water naturally mineral-rich. While it does not soften hard water, the system's ability to preserve essential minerals provides a healthier, better-tasting alternative to methods that strip water of all dissolved solids, ensuring you get the benefits of purified water without sacrificing essential nutrients.

Frequently Asked Questions

No, Berkey filters do not remove beneficial ionic minerals like calcium. The filtration media is designed to allow these minerals to pass through to the purified water.

A TDS meter can be used to test water filtered by a Berkey. The TDS reading should be approximately the same before and after filtration, as the Berkey retains beneficial minerals that contribute to the TDS measurement.

Yes, you can use a Berkey with hard water. However, the mineral buildup from hard water may cause your filters to clog and slow down over time, requiring more frequent cleaning.

Many people prefer that their drinking water retains minerals like magnesium because they are essential for bodily functions and can improve the taste of the water. Indiscriminately removing all minerals can result in a bland, flat taste.

The proprietary Black Berkey filter media uses ion exchange and adsorption to selectively remove contaminants with specific ionic charges, while allowing beneficial minerals with different charges to pass through.

No, Berkey-filtered water is not the same as distilled water. Distillation removes all dissolved minerals, whereas Berkey retains them. Distilled water can have a flat taste due to the lack of minerals.

No, you do not need to add minerals back into Berkey-filtered water, as the system does not remove them in the first place. You only need to add minerals to water purified by methods like reverse osmosis or distillation.