What is the difference between ZeroWater and Clearly Filtered?

If you are considering either a Clearly Filtered or ZeroWater pitcher, you’ve come to the right place. Here we’ll explain everything you need to know about Clearly Filtered versus ZeroWater and why you may want to choose one over the other. We will cover everything from filter effectiveness to cost to ease of use, so you can make an informed decision or have an informed discussion.

Clearly Filtered Water Pitcher vs. ZeroWater Pitcher. Which one is better?

The answer depends on what you are looking for in a water filter. While both options are much better than your typical carbon filter, there are some important differences you should know before making your decision.

The Pitcher

  • Capacity
    The amount of water each pitcher holds is about the same. However, the ZeroWater pitcher’s top reservoir is relatively small compared to the size of the pitcher, and people have reported having to fill the reservoir multiple times in order to fill the pitcher completely. The Clearly Filtered pitcher has a unique water dam that prevents the unfiltered water from mixing with the clean water while pouring. This allows you to fill up a glass without having to wait for the pitcher to completely finish filtering.

The Filter

  • Number of contaminants targeted (365 vs. 23)

This is where Clearly Filtered really excels. The Clearly Filtered pitcher targets over 365 different chemicals, metals, and impurities, while the ZeroWater pitcher filters just 23 (here's a link to their website so you can see for yourself). If you’re looking for the filter that can remove the most contaminants, Clearly Filtered filters over ten times more than ZeroWater.

  • Filter life span (100 gallons vs. 20 gallons)

The Clearly Filtered pitcher filter has been tested to 100 gallons, while ZeroWater’s pitcher performance data only tests to 20 gallons. ZeroWater's claim of the filter lasting up to 40 gallons based on the reading of your tap water's TDS is not something we condone as we prefer to use a lab and data to back up our claims of filtration capabilities as well as filter life expectancy.


One major advantage of ZeroWater is cost. The pitcher and its replacement filters are considerably cheaper than the Clearly Filtered options. However, it is important to consider the shorter life span of the ZeroWater filter when calculating overall costs. A shorter life span means having to purchase more filter replacements (5 times more often for ZeroWater vs. Clearly Filtered!). This is an important detail not to be overlooked.

And don’t forget the saying, “you get what you pay for.” When it comes to cars, phones, and televisions, it’s no surprise that you are required to pay more for the most sophisticated technology. Clearly Filtered is no different.

  • ZeroWater 10 Cup Pitcher: $34.99
  • ZeroWater Replacement Filter: $34.99 for a 2-pack ($16.50/filter)
  • Clearly Filtered Pitcher: $81 (on subscription)
  • Clearly Filtered Replacement Filter: $49.50 (on subscription)


Understanding “Total Dissolved Solids” (TDS)

ZeroWater places a great deal of focus on Total Dissolved Solids (TDS). The product even ships with an at-home TDS meter and they encourage customers to “test” their water so that it shows “000” parts per million (ppm). The goal of having people do this is for them to assume the meter is measuring the level of contaminants in their water. But what if we said that it is the wrong tool for the job? An understanding of TDS and TDS meter limitations is essential to understanding why you could have “000” TDS and still be drinking water that is unsafe.

What are “Total Dissolved Solids” (TDS)?

TDS refers to substances dissolved in water that have an ionic charge. This can include not only a wide variety of contaminants, but also beneficial minerals such as calcium, magnesium, sodium, and potassium that naturally occur in water. Unlike the name suggests, TDS isn’t necessarily a bunch of bad stuff floating in your water. The name can be quite misleading.


As such, we have come to learn that the number of dissolved solids in your drinking water is not an accurate measure of contamination. Instead, measuring TDS can provide consumers with a false sense of security.

How is TDS measured?

Despite what the name Total Dissolved Solids seems to imply, TDS meters aren’t actually measuring contaminants floating in tap water. Instead, a TDS meter measures electrical conductivity (how quickly an electrical current travels through water) to estimate the number of ionically-charged, non-water particles present. The assumption is that the slower the current travels, the more “contaminants” that are present. But this is not the case. Some contaminants, as well as some minerals and nutrients, do not have an ionic charge and therefore cannot be measured by the meter. You can gain a more in-depth understanding of TDS here

Why is TDS the wrong tool for measuring water quality?

It’s important to know that TDS isn’t actually measuring water quality. There are many things that show up on a TDS meter that are beneficial, such as minerals that give water its taste and aid in hydration.

Does a TDS meter actually work?

1. TDS meters can’t tell you what they’re measuring.

TDS meters cannot distinguish WHAT is in the water and do not indicate what a TDS reading is detecting. Relying on a TDS meter can be deceptive for customers who may mistake minerals being measured as potential contaminants.

2. TDS meters only measure in PPM (parts per million)—and that’s a problem.

One part per million may sound like a really small amount. However, there are hundreds of dangerous contaminants such as lead, chromium-6, and PFAS that are harmful and toxic at levels so much lower than 1 PPM they would not even show up on a TDS meter. These substances are actually measured in much, much smaller amounts called PPB (parts per billion). As a reminder, there are 1,000 million in a billion, so these contaminants are dangerous at levels up to 1,000 times smaller than what would register “001” PPM on a TDS meter.

For example, the legal limit of lead is 0.015 PPM. A TDS meter could not pick up lead until it reached a concentration of 1 PPM (67 times the legal limit!). This means the meter could read “000” even though 67 times the legal limit of lead was present in the water. (On the other hand, Clearly Filtered products are able to detect and remove contaminants found at levels as low as parts per billion).

A TDS meter would not pick up lead in water (and read 001 PPM) until it reached a concentration that is 67 times the legal limit (0.015 PPM).

3) TDS meters are not scientific devices.

One thing to remember when thinking about TDS and water quality is the quality of the tool you’re relying on for your information. A $2.00 TDS meter that is included with a water pitcher is neither laboratory-grade nor used by any laboratories in the country for the purpose of contaminant water quality analysis.

Instead, water quality performance testing like that performed by Clearly Filtered is done with highly sophisticated laboratory equipment such as masspectrometers and spectrophotometers that cost $25,000-$50,000 and measure down to the parts per billion. Simply put, a TDS meter is not a scientific device, which begs the question: Do you really want to put your faith (and health) in one?

As a result of all of these flaws, there is no feasible way for an inexpensive TDS meter, such as the one included with Zerowater filters, to determine the quality of your water or to guarantee that your water is safe.

Does Clearly Filtered Target TDS?

Yes, Clearly Filtered does filter some dissolved solids. However, Clearly Filtered does not remove the healthy and beneficial minerals and nutrients found naturally in water. This is one of the reasons why you should not expect to see a reading of “000” if you use a TDS meter to test water filtered through a Clearly Filtered pitcher.

This shouldn’t be alarming, as there are no naturally occurring water sources anywhere on the planet with 000 TDS. We are also not trying to remove TDS. As a policy, Clearly Filtered does not use TDS meters as they are nowhere near accurate enough to measure any useful water quality data point. Clearly Filtered’s CEO claims, “We are against TDS testers because they are being marketed to people as a test and are being completely misrepresented as a tool to check your water quality. It’s actually dangerous. People should NOT rely on a TDS meter. If they did, they could very well be drinking water with harmful levels of contaminants like lead that would never show up on a TDS meter that only measures in parts per million.”

"People should NOT rely on a TDS meter. If they did, they could very well be drinking water with harmful levels of contaminants . . ."

Clearly Filtered vs. ZeroWater: Technology 

There are major differences in the way each filter removes contaminants. ZeroWater claims to use an ion exchange resin, while Clearly Filtered uses a blend of 7 different filtration medias collectively referred to as Affinity Filtration Technology. Using the extent of contaminant removal as a measure of effectiveness (365+ for Clearly Filtered vs. 23 for ZeroWater), Clearly Filtered technology has the edge, while ZeroWater is a cheaper alternative.

Clearly Filtered’s Affinity Filtration Technology uses both magnet-like chemical adsorption and a unique physical structure to provide superior contaminant removal. Through chemical adsorption, harmful contaminants are drawn to and locked into the proprietary filtration media, filtering them from your water. The structure of the filter also enables maximum contact between the water and filtration media, allowing removal of up to 99.9% of contaminants. This dual-approach allows unique targeting and elimination of contaminants at a microscopic scale. In fact, Clearly Filtered is so powerful that it is able to target contaminants present at levels measured in parts per billion.

For reference, 1 part per billion is equivalent to 1 drop in an Olympic-sized swimming pool. This is important, as certain contaminants are harmful even at these extremely low levels.

Compare this to ZeroWater, which uses a staged ionic exchange filtration process. The goal of this process is to remove TDS rather than actually targeting and removing specific contaminants. The downside of this is that it also removes water’s beneficial nutrients and minerals in order to achieve “000” TDS.

Which filter is right for you?

You’ve done your research, and hopefully, you now feel well informed and ready to make a decision between Clearly Filtered vs. ZeroWater. If you are looking for more extensive contaminant removal, longer filter life, premium materials, and superior technology, Clearly Filtered may be the right choice for you. Explore the full line-up of Clearly Filtered products to learn more.


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