Are Gravity Water Filters Good? | Things You Must Know

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Gravity water filters are perhaps less well-known than reverse osmosis systems – but that doesn’t mean they aren’t worthy of consideration. While deceptively simple in design, these filters can do an incredible job purifying water.

If you’re familiar with cheap pitcher-style water filters, you might be tempted to think that’s all gravity filters have to offer. The reality is quite different, however.

Let’s take a closer look at gravity water filters – and break down if they are any good and have a place in modern home water filtration.

Key Takeaways

  • Yes, gravity water filters are good.
  • Gravity water filters are relatively simple in terms of design and function – but that doesn’t mean they aren’t effective. Despite being one of the oldest filtration methods still used today, they can be highly effective at removing a wide range of contaminants.
  • The key to gravity filter effectiveness is the long contact period between the filter element or elements and the water. This provides the opportunity for thorough filtration.
  • Gravity filters have the advantages of being relatively inexpensive, easy to install/maintain, not requiring plumbing or electricity to operate, and working well in emergencies.

Are Gravity Water Filters Good?

Yes, gravity water filters are good – at least they can be.

Right off the bat, it’s important to state that many gravity water filters are a lot more effective than they first appear.

These systems – as the name suggests – use the force of gravity to propel water down from an upper chamber and through one or more filter elements before sending it to collect in a lower chamber. The use of gravity instead of water pressure allows for a long contact period between the filter element and the feed water that, while time-consuming, increases the filter’s efficacy.


Gravity filters are highly effective at contaminant removal, provided you have the correct filter to target the impurities in your water. With better models, you can expect somewhere in the range of 95.0-99.9% or more effectiveness for microbial contaminants, chlorine/chloramine, heavy metals, VOCs, and pesticides and other chemicals, as well as rust/silt/sediment.

Higher-end models will typically be NSF-certified and tested, which guarantees the manufacturer’s claims about the filter’s effectiveness.

Look out for the following NSF certifications:

  • Standard 42 – For cosmetic effects like water taste and odor. Primarily measures the reduction of chlorine and large particles.
  • Standard 53 – For contaminants with proven health effects. Measures the reduction of lead, chromium 6, and over 50 other heavy metals and contaminants.
  • Standard 401 – For emerging chemicals with sometimes unknown but possible health effects. Measures reduction in pesticides, herbicides, prescription drugs, and other compounds.
  • Standard 244 – For different forms of microbiological contamination. Viruses, bacteria, cysts.

Is a Gravity-Based Water Purifier Safe for My Health?

So, are gravity-based water purifiers safe for your health?

Naturally, the answer will depend on the specific filter in question as well as the contaminants in your water. The most harmful contaminant – especially in the short term – are microbial contaminants.

If your water is supplied through a municipal source then chances are good it will be free of these contaminants due to chemical treatment. However, if you’re water is supplied by a well or you’re planning an outdoor excursion, then you’ll want to ensure your system can handle microbial contamination.

Gravity filter bags/bladders are portable devices designed specifically for use with non-potable water sources like ponds, lakes, and creeks. These are ideal for camping and hiking – where you can’t be sure of your water’s quality.

gravity bag water filter

If you’re concerned with other contaminants like heavy metals, VOCs, pesticides, etc., then as long as you ensure your filter is rated to handle the contaminant in question you should have no issues.

What Is a Gravity-Based Water Filter and How Does It Work?

Gravity-based water filters are relatively and utilize the force of gravity to propel water from an upper chamber, through a filter element or elements, and into a lower chamber for storage.

This simplistic design allows the system to operate completely without electricity or a plumbing connection. Feed water is poured directly into the top tank, which means the system has to be filled manually.

The most important part of any gravity filter system is the filter in the middle. These are what determine which contaminants will be filtered out of your water.

Many gravity filters use some type of ceramic often filled with carbon and/or ion exchange media in its core. This allows for removing many different types of water contaminants.

Gravity Water Filter Pros & Cons

Pro: Installation

Gravity filters are simple and easy to install. All that’s needed to set one up is opening up the package, setting it up on the counter, priming and installing the filter(s), and filling the upper chamber with water.

Notice once again that no electrical or plumbing hookups are required to install a gravity filter.

Pro: Cost

Gravity filters are fairly inexpensive when compared to other filtration systems. A high-quality unit will run you between about $100 and $350, which may not sound that cheap, but when you add in the cost of filter changes, it starts to make a lot more sense.

Pro: Maintenance

Gravity filter maintenance is extremely minimal. All that’s required is occasional cleaning/changing of the filter elements and cleaning the water tanks from time to time.

Pro: Emergencies

While this may not be a priority for you, gravity water filters are the ideal water filter in emergencies.

Con: Manual Refilling

While other water filtration systems are supplied directly through a connection to your home’s plumbing, gravity-based systems are filled by pouring water directly into the upper chamber. This can be somewhat inconvenient when compared with the ease of opening a faucet.

Con: Limited Purification

Although gravity-based systems are capable of thorough filtration, especially multi-stage filters, they often still don’t achieve the same level as more advanced methods.

Con: Wait Time

Long waiting time may be the biggest drawback of gravity-based water systems. The fact that a typical gravity-based system will often take one and up to several hours to finish filtering means that you’re going to need to wait for a while after refilling the system.

You can mitigate this somewhat by purchasing a system with a large capacity, but it will still require manual refilling and waiting.

When to Use a Gravity Water Filter

You should use a gravity-based water filter when you want a filter that won’t cost an arm and a leg, that’s easy to install and set up, requires minimal maintenance, doesn’t require any electricity or a plumbing hookup, and will work in emergencies and off-grid situations.

If you have any thoughts about the question, are gravity water filters good, please don’t hesitate to leave a comment below!

About the Author Gene Fitzgerald

Gene Fitzgerald is one of the founders of BOS and currently head of content creation. She has 8+ years of experience as a water treatment specialist under her belt making her our senior scientist. Outside of BOS, Gene loves reading books on philosophy & social issues, making music, and hiking.
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