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ZeroWater Filter Review

Derek Hales

Written By: Derek Hales

Updated on:

ZeroWater is a relatively new water filter system that promises water with zero dissolved solids. Does it live up to the task? Find our below.

Zero Dissolved Solids Filter

ZeroWater filter

ZeroWater Filter

The ZeroWater filter claims to reduce TDS (total dissolved solids) in your water all the way to zero; in our tests it did exactly that. We tested it against some of the hardest water in the US in Phoenix, Arizona. Even with starting values in the 500 ppm range the ZeroWater filter was able to reduce TDS to zero. The water was almost shockingly pure tasting. Honestly, I’m so used to drinking high TDS water that it will take time to get used to. Arguably the best water filter currently on the market.Check Price


  • Great performance at removing TDS (total dissolved solids), in all of our tests it did indeed hit a TDS of 0
  • Water is extraordinarily pure of anything except water
  • TDS performance relative to other common filters was night and day. PUR and Brita struggled to remove even 30% of TDS in our test water (Phoenix, AZ source). See our Brita vs. PUR vs. ZeroWater comparison.


  • Slower filtration speed due to the 5-stage system, filters about 0.8 cups every minute.
  • May remove good minerals naturally found in water during the filtration process

If you would rather watch a video instead of reading, we’ve got our complete ZeroWater video review here:

ZeroWater Design

The ZeroWater system is designed to purify water by effectively reducing the number of total dissolved solids. The water filter installs into a variety of different pitcher sizes—from 6-cup to 40-cup capacities.

Zero water filter - pitcher shown
ZeroWater filter – pitcher shown

No matter which pitcher size you select, all ZeroWater systems come with the same 5-stage filter.

5-Stage Filter

This filter uses a 5-stage system that removes particulate through a series of filtrations. Although you can’t see many of these layers on the outside, the 5 stages are listed below.

Zero water filter replacement
ZeroWater filter replacement
  1. Coarse filter screen: captures fine particles and sediment
  2. Foam distributer: disperses water evenly across the entire width of the filter for more effective filtration
  3. Carbon filter: filters out additional contaminants and helps improve taste; also includes an oxidation alloy for removing chlorine and other heavy metals
  4. Ion exchange resin: a bed of resin towards the bottom of the filter for removing foreign ions from the water
  5. Fine screen: includes a screen and non-woven membrane layer to remove ultra-fine particles
zero water filter - 5 stage filtration
ZeroWater filter – 5 stage filtration (inside look)

How does it work?

Pour water from the sink or any tap into the top of the pitcher. As the water travels through the filter, it moves from the top reservoir of unclean water down into the lower reservoir of clean water, ready for drinking.

Due to the 5-stage filter, filtration may take longer with the ZeroWater system than comparable other systems (like Pur or Brita).

In our tests it took the ZeroWater filter 6 minutes to filter 5 cups of water. That’s a rate of about 0.8 cups / minute.

What contaminant does it remove?

ZeroWater is rated to remove up to 95% of contaminant and impurities. The results below were independently derived from ZeroWater, in accordance to the EPA drinking water standards.

MORE: Click here to learn more about how ZeroWater is tested.

Average Reduction of Listed METAL Contaminants

  • Antimony: 97%
  • Arsenic (+3): 83%
  • Arsenic (+5): 93%
  • Asbestos: 97%
  • Barium: 98%
  • Cadmium: 99.9%
  • Chromium 3: 81%
  • Chromium 6: 99.9%
  • Copper: 99%
  • Cobalt: 99%
  • Iron: 98%
  • Lead: 97%
  • Manganese: 98%
  • Mercury: 96%
  • Selenium: 98%
  • Silver: 81%
  • Thallium: 99%
  • Uranium: 99%
  • Zinc: 98%

Average Reduction of Listed Inorganic Contaminants

  • Chlorine: 95%
  • Cyanide: 31%
  • Flouride: 41%
  • Nitrate: 74%
  • Nitrite: 81%
  • Sulfide: 55%

What’s in the box?

The ZeroWater filtration system comes with the follow:

  1. Pitcher / Tank (varies by model)
  2. Electronic TDS water testing meter
  3. Filter cartridge
ZeroWater filter detail shot


To test the performance of the ZeroWater filter, same as all of our water filter tests, we use two methods.

  1. TDS test: tests the number of “total dissolved solids”
  2. Taste test: uses a small group of individuals to blindly taste the water and provide a score based on taste alone

TDS Test

This test uses a TDS meter to evaluate the number of “total dissolved solids” that are found in the water.

ZeroWater encourages consumers to put the water to the test and even includes a TDS meter for free with the purchase of a filter + pitcher combo.

TDS meter (total dissolved solids)
TDS meter (total dissolved solids)

What are dissolved solids?

Dissolved solids basically boil down anything extra in the water. Under this measuring method, a score of 0 would represent the purest water you can get. Anything higher than that would mean that there are still contaminant, chemicals, or other additives in the water that contribute to the overall score.

NOTE: Dissolved solids are not always bad. Sometimes solids are added to improve taste or many includes naturally occuring minerals.

Saltwater, for example, can be natural and pure, but the salinity in the water alone would increase its TDS score.

Mineral water also would have a high TDS level.

Water filters struggle to tell the difference between good solid and bad solids so ZeroWater takes it all out.


Overall, the performance of the ZeroWater filter was exceptional. It reduced all TDS down to 0 for all of our performance tests.

For comparison, I’ve dropped in a side by side of Pur vs. Brita as well. Below is a before and after for TDS for each filter.


ZeroWater filtration system
  • Before: 542 ppm
  • After: 0 ppm


PUR Basic water filter pitcher review
  • Before: 542 ppm
  • After: 511 ppm


Brita Everyday water filter pitcher review
  • Before: 542 ppm
  • After: 396 ppm

The source for our water test was city water from Phoenix, Arizona. Arizona has some of the highest TDS water in the country, making our test extremely difficult on all purifiers we tested.

ZeroWater released the following water level TDS by state.

RELATED: Click here to read the full review of PUR vs. Brita comparison.

Taste Test

In addition to our TDS test, we also completed a short taste test. For our taste test we used Modern Castle team members as well as a small group of our friends / family.

ZeroWater taste test
Dramatic action shots of the taste test

Here’s how we did our taste test:

  • We poured 3 types of water into 3 paper cups
  • Types of water included filtered ZeroWater, filted PUR water, and filtered Brita water.
  • Testers tried each of the 3 water types
  • We then asked testers to rate the water on a 1-5 scale, with 5 being the best
  • Finally, we then created an average score based on those ratings

Taste Test Results

Our results were definitely surprising. The scores are below.







On average, our testers rated the ZeroWater at a 60% out of 100%. PUR and Brita were preferred when it comes to taste, earning a 69% and 83%, respectively.

ZeroWater taste test
Our scoring sheets for the tests

One of our taste testers said this about the ZeroWater:

“I can tell it’s pure, but I just don’t like the taste.”

Taste Tester

While I personally felt that the taste was fine, I will say that the taste is shocking. The ZeroWater removes everything…bad solids, good solids, and everything in between. As a result, the water tastes very different from any other water I’m used to.

Our water source is Phoenix, Arizona, some of the hardest and highest TDS water in the country. Most filters can only reduce TDS by 20-30% for Phoenix water, which still puts it in the 300-400 range, even in the best of cases.

ZeroWater taste test

Completely eliminating the dissolved solids gives it a unique and surprising taste.

I wouldn’t say it’s bad, only that it’s different. In my view, that difference is what’s so shocking to many testers. I think a lot of people would find it weird tasting, while others will absolutely love it. But it really will be a personal preference.

The Pitchers

There are quite a few pitchers you can get for the ZeroWater filter, depending on your needs.

Zero water filter - pitcher size options (6, 8, 10, 23, or 40 cup capacity)

Current available sizes include:

  • 6-cup pitcher
  • 10-cup pitcher
  • 18-cup pitcher
  • 23-cup pitcher
  • 40-cup tank


Maintaining this water filter mainly includes replacing the filter as needed. Other than that, simply use the filter as often as want to drink water, and replace as needed.

When is it time to replace the filter?

The length of time your fitler will last is dependant on the initial TDS score of your unfiltered water. Water that requires more filtration means that the fitler will not last as long.

Here’s how many liters of water you can expect from each TDS level:

Tap Water TDSContaminant LevelDescriptionExpected Quantity of ZeroWater per Filter
000-001Meets FDA standards of purified bottled waterNo known municipalitiesN/A
002-050ModerateNaturally occurring in only a few cities150 liters or more
051-200TypicalAverage for most homes95 - 150 liters
201-300HighHigher number of contaminants means slightly lower capacity55 - 95 liters
301-400Exceptionally HighShorter filter life than expected30 - 55 liters
401+ExtremeVery short filter life30 liters or less

The manufacturer recommends changing the filter when the TDS meter reads “006” or higher. Allowing the filter to be used beyond that point may result in a difference in the water’s taste or smell.

How to replace the filter?

To replace the filter, simply unscrew it from the base of the pitcher (may vary based on the model) and screw in a new filter.

ZeroWater filter installation

REPLACE: You can find ZeroWater replacement filters here or click here to check the price for third-party replacement filters.

Should you buy the ZeroWater filter?

On the fence about if the ZeroWater system is right for you?

I would recommend this system if you’re looking for the following:

  • Maximum removal of total dissolved solids: During our performance tests, this filter removed 100% of dissolved solids every time. It is massively better at removing solids compared to more traditional filters like PUR and Brita, which achieved TDS scores of 511 and 396, respectively, in our tests.
  • Want 5-stage filtration: Many conventional filtration system uses a 2-stage system, but ZeroWater prides itself on the 5-stage system.
  • You’re okay getting used to the new taste: Because ZeroWater removes so many of the dissolved solids it gives the taste a surprising and different taste. Be prepared for the new taste and realize it might take some time to get used to.

Click here to learn more or to buy the ZeroWater filtration system.


  • June 12, 2020 – Updated test taste data was published. The new expanded taste tests saw an improvement to Zero’s taste test score, from a 46% to a 60%. However, Zero is still behind PUR and Brita’s taste test, which earned a 69% and 83%, respectively. Zero’s review score was not altered.
  • June 3, 2020 – Initial version of the page was published.
Extraordinary Purificatio
  • Design - 98%
  • Performance - 100%
  • Quality - 95%
  • Usability - 95%
  • Value - 98%


The ZeroWater filter uses a 5-stage filter to remove 100% of dissolved solids from water. Removes and reduces a litany of common metal, inorganic, and other particulates from water, including lead, mercury, asbestos, among others. It our tests it was able to reduce a high TDS water source from 542 ppm to 0 ppm. It lacks so many particulates that the water’s taste is surprising (so much so that it took me a while to get used to it). Overall, an extraordinarily high performance water filter, especially at this price point.

About Derek Hales

Derek HalesDerek Hales is the Founder and Editor-in-Chief of He has been featured in Fast Company, Reader's Digest, Business Insider,, She Knows, and other major publications. Derek has a Bachelor's Degree in Business Administration from Kansas State University. Hales has been testing and reviewing products for the home since 2014.

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7 Comments on “ZeroWater Filter Review”

  1. I started noticing a rotten meat smell in my kitchen, long story short it is coming from my zero water! My filter is only three weeks old and I bought the system brand new. The water tasted really good at first but now it really stinks. I really want to love zero water because it did taste so good. The reading on the meter says all 000’s. Every container the water has been has a faint smell of rotten meat.

    • Hrm… interesting. It sounds like the filter just reached it’s end of life, but if it’s still returning all zeros then that sounds like you have a defective filter.

      I’d get them to refund your money for that.

  2. The new filter has a rigid screen-like top instead of course filter that one could release air bubbles that slowed filtration time dramatically. This new filter slows filtration to intolerable. What’s the deal? Work around?

    • Take a knife and stab 2-4 holes through the screen, taking care to not poke too deeply into the filter itself. That’s what I’ve done and it seems to work reasonably well.

      Some filters are worse than others though. So only poke as many holes as you need.

  3. Zero water user for 10 yrs. Why did I get yellowish/orange sludge backup in the top reservoir this one & only time? What is that & Why? Is it dangerous?

    • I’m not sure about that. But if it’s in the top reservoir that would indicate a problem with your water source, not with Zero.

      I’d be safe and clean everything, get a new filter, etc.

  4. I really would love one of these filters for my refrigerator. You should make them too. I pay $46.00 every 6 months to replace my filter. Water is all I drink about 2 gallons a day.