ZeroWater Review: We Tested 3 of Their Water Filters

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ZeroWater is one of the better-known water filter pitcher manufacturers, using 5-stage gravity filtration that promises to bring your water’s TDS (or total dissolved solids) down to 0. Lots of people claim that ZeroWater filters are the best out there, and we were keen to see whether they’re worth the hype.

We’ve tested three ZeroWater pitchers and dispensers in our own home. In this review, we’ve commented on how they improved our water quality, their ease of use, their overall value for money, and more. We’ve also discussed why we have a problem with ZeroWater’s marketing promises.

🎥 Video Review

🧾 Overview of ZeroWater Filters

ZeroWater (or Zero Water) is an affordable water filter brand that sells faucet water filters, water filter pitchers, and water filter dispensers.

We’ll be discussing the ZeroWater filter pitchers and dispensers in this guide. The products we have personal experience with are:

Zerowater pitcher and dispensers on countertop table

ZeroWater’s pitchers and dispensers all use the same 5-stage water filter cartridge, which is a gravity filter.

The idea is that you fill the top compartment of the pitcher or dispenser, then wait for the water to filter through into the bottom compartment. Then, depending on whether you’re using a pitcher or a dispenser, you can pour water from the spout or open the spigot.

ZeroWater’s main selling point is that its filter reduces almost all TDS from water. All ZeroWater products come with a TDS meter so you can check that the filter is working properly.

The filter has been tested to remove 43 common contaminants, and has been NSF certified to Standards 42 and 53 for its filtration performance.

Zero Technologies (the warrantor) offers a 90-day warranty for ZeroWater dispensers and pitchers. If you detect a manufacturing defect within this timeframe, you can make a warranty claim to receive a free replacement part. We couldn’t find any mention of a warranty for the 5-stage filter.

ProductZeroWater 12-Cup Ready-Pour Pitcher
Ready-Pour Pitcher
ZeroWater Ready-Read Dispenser
Ready-Read Dispenser
ZeroWater 40-Cup Glass Ready-Pour Dispenser
Glass Ready-Pour Dispenser
TypePitcherDispenserDispenser
Ratings5/55/54.5/5
Price$39.99$44.99$74.99
Contaminants Reduced43 4343
Certifications or TestingNSF 42 & 53NSF 42 & 53NSF Certified Components
Holding Capacity12 cups 32 cups20 gallons
Filter Life40 gallons40 gallons
Annual Cost~$160~$40~$60
Warranty90-day warranty90-day warranty90-day warranty
Buying Options


In our testing, the ZeroWater filter pitchers and dispensers did a great job of improving our water quality, and we really appreciated the NSF certifications to assure us of their contaminant removal abilities. We were less impressed with the 40-50-gallon filter capacity, which is one of the worst we’ve seen for a filter of this kind. We also found that, because of the 5-stage gravity filtration, it took a long time to send water through the filter.

👍 What We Like

  • Super easy press filtration (no difficult-to-use filter straw or pump)
  • Eliminates the need for plastic water bottles
  • Targets bacteria and viruses
  • Attractive bottle design
  • Provides quick filtration – no waiting for gravity
  • Carbon filter component improves taste of water & removes additional dangerous contaminants

👎 What We Don’t Like

  • 40-50-gallon filter lifespan is low compared to similar filters
  • We had to replace our filters at least every 1-3 months, incurring a greater maintenance cost
  • Slow filtration speed
  • Demineralizes water

💡 First Impressions

Our first impression of the Zero Water filters was positive. They’re on the affordable end of the water filter pitchers and dispensers we’ve reviewed, with a starting price of just $25 for the 7-Cup Ready-Pour Pitcher. The 40-Cup Ready-Pour Glass Dispenser is ZeroWater’s most expensive offering, at $75.

The packages we received contained the following items:

  • The pitcher/dispenser body
  • The upper reservoir
  • The first filter
  • The lid
  • The TDS meter

The majority of the Zero Water filter pitchers and dispensers are made of BPA-free polypropylene and ABS (a terpolymer).

Polypropylene is a super popular material used for water filters because it’s durable, flexible, and highly resistant to moisture absorption, as well as being free from BPA and BPS. ABS is a food-grade plastic, which is non-leaching and mold-resistant. We did find that the plastic feels a bit thinner and flimsier than pitcher/dispenser units made of Tritan plastic.

We found that the 12-Cup Ready-Pour Pitcher and the Ready-Read dispenser were lightweight and easy to carry – especially the pitcher, which we could carry with one hand even when it was full.

The exception is the Zero Water 40-Cup Glass Ready-Pour Dispenser, which is made of glass. This dispenser is heavier, at 12.5 pounds (in comparison, the 32-cup Ready-Read dispenser weighs just 5.5 pounds). But it’s not intended to be lifted once it’s been set up at the install location anyway.

Getting Started & Our Thoughts on Design

Getting started was really easy – we just had to assemble the pitcher or dispenser.

Unlike most other gravity filters we’ve tested, Zero Water filter cartridges don’t need to be primed or soaked before use, which saved us a ton of time and meant we could start enjoying filtered water straight away.

Once assembled, we thought the filters and dispensers looked pretty conventional, with no super unique features that made them different from other similar units sold today:

  • The 12-Cup Ready-Pour Pitcher has a traditional pitcher shape, with a reservoir that slots into the top of the unit. The filter screws into the bottom of the reservoir. We could pour from the pitcher and only filtered water would leave the spout.
  • The Ready-Read dispenser is rectangular, with a plastic spigot. It needs to be positioned at the edge of a counter or a sink so that you can fit a glass underneath it.
  • The 40-Cup Glass Ready-Pour Dispenser is cylindrical, with a plastic spigot. The spigot is high enough that you can position a smaller glass underneath without having to put the dispenser on the very edge of the counter. We found that if the dispenser was sitting too close to the edge, we had an issue where we would bump into the spigot and accidentally turn it on and water would start running out.
Brian placing the ZeroWater Glass Dispenser to the base

In all, on first inspection and use, we thought the Zero Water water pitcher and dispenser units were simply but solidly built, with a good variation of water-holding capacities. We appreciated the glass option as a plastic-free alternative (although we wish the spigot was also all-glass).

🧪 Our Testing

We’ve used our Zero Water filters to filter city water in our home in Colorado. We wanted to test them for a few specific performance factors, including how they affected our water quality, how long they took to filter our water, their ease of use, and more.

We’ve discussed these factors in detail below.

Our Water Taste, Smell, & Quality

First, we wanted to see how the Zero Water filter could improve the taste, smell, and overall quality of our water.

The Zero Water filter cartridge that’s used across all dispensers and pitchers uses five filtration stages, including 3 layers of physical filtration, ion exchange resin, and activated carbon media. The filter has been tested to remove 43 different contaminants, including metals like arsenic, lead, and chromium, as well as fluoride, chlorine, and PFAs.

We expected that our filtered water would taste better given the inclusion of activated carbon media in the filter. Activated carbon is widely used for water filtration because it removes contaminants associated with taste and smell, namely chlorine.

We taste-tested our unfiltered tap water and compared it to our filtered water, and here were the key things we noted:

  • All chlorine tastes and smells were gone
  • Our water tasted clean and fresh, if not a bit plain
Filtering tap water with ZeroWater 12 cup

We think the reason why our water tasted “plain” is because the filter’s ion exchange resin removes minerals like calcium and magnesium, which give water an alkaline taste.

In a study of 15 bottled mineral waters, calcium, magnesium, sodium, and potassium were highlighted as the key mineral nutrients that give water its unique flavor. Without these minerals, and given that our water’s TDS was close to 0, our water was lacking any properties to enhance its taste.

Important taste information: Towards the end of the filter life, our filtered tap water took on an unpleasant, slightly acidic taste. This is due to the ion exchange resin degrading, which releases an organic compound called trimethylamine, and has been experienced by numerous other customers (some describe the taste as sour, lemony, or even fishy). We’ve found that the only way to prevent this smell is to frequently wash out our pitcher/dispenser and replace the filters on time.

We haven’t been able to obtain firsthand testing data for the Zero Water 5-stage filter yet, but it’s on our list, and we’ll update our review when we have these results.

TDS Reduction

Since a big part of Zero Water’s marketing is that its 5-stage filter can greatly reduce TDS, we wanted to see how much TDS the filter could reduce from our own water.

We used the included TDS meter to test our water’s TDS before filtration, and post-filtration.

We first did this test when we’d started using a new filter, so we could see exactly how much TDS it could reduce before its filtration became less effective as it neared the end of its lifespan.

Our unfiltered water had a TDS reading of 31, and this reading went down to 0 in our filtered water. We got the same reading of 0 after two weeks of use. That meant the filter did the job of reducing our water’s TDS as advertised. However, we still have issues with ZeroWater’s marketing, which seems to insinuate that all dissolved solids are bad (we’ve discussed this later in the review).

Zerowater tds meter

Ease of Use

We were also keen to test how easy the Zero Water filtration systems were for us to use.

We wanted something that we could easily integrate into our everyday routine, and the Zero Water systems ticked our boxes.

A big advantage for us was that the systems are countertop gravity units, so we didn’t have to waste time installing them at our water line.

However, this does have its setbacks – it meant we had to fill the pitcher/dispenser manually throughout the day, so we always had filtered water whenever we needed it.

The dispensers were particularly easy to use because we could dispense water straight from the spigot. However, they were less practical and needed to be kept in one location. Unlike the 12-Cup Pitcher, they couldn’t be carried when full.

One setback of the pitcher design that we noticed was that if we tilted the jug too much, a lot of water would come out of the spout all at once.

Zero Water filters reduce TDS like reverse osmosis systems, but, unlike reverse osmosis, they don’t waste water. That meant we could enjoy a similar filtered water quality without having to empty batches of wastewater down the drain.

Brian pointing at the TDS meter of ZeroWater Ready Read Dispenser

Filtration Time

Filtration time is something that we were less impressed with.

We expect gravity filters like pitchers and dispensers to filter water more slowly because they’re not powered by water pressure.

This is one of their setbacks compared to other types of filters, like faucet filters and under-sink filters, which are connected to your water line and deliver filtered tap water on demand.

But the Zero Water filter system works very slowly, even by a gravity filter’s standards.

We think this is because the filter combines 5 filtration stages in one cartridge, so there’s a lot of resistance as water travels through. The good news, at least, is that means water gets plenty of contact time with the filter media.

We got into the habit of filling our pitchers and dispensers as soon as we woke up, then topping up the unfiltered water reservoir wherever we dispensed some filtered water, so we always had filtered water ready to drink.

Filtering water with zerowater filter

📑 Filter Testing & Certifications

The Zero Water 5-stage water filter is NSF certified to Standard 42 and Standard 53 for the reduction of chlorine taste and odor, chromium 6, lead, mercury, PFOA, and PFOS.

The manufacturer has also obtained independent testing using EPA-approved methods to demonstrate the filter’s ability to remove 43 different contaminants from tap water (view the independent lab testing data here).

We appreciate ZeroWater’s transparency, but we wish the filter could be tested to remove additional contaminants of concern, including pesticides, chloramine, pharmaceuticals, radionuclides, microplastics, and VOCs.

See the full list of contaminants that the Zero Water filters have been tested to remove below.

Contaminant15 Gallons Filtered130 Gallons Filtered20 Gallons Filtered
Antimony99%96%99%
Arsenic III98%85%63%
Arsenic V98%93%94%
Barium99.9%99.9%96%
Beryllium97%97%94%
Cadmium97%97%97%
Chromium 398%94%93%
Chromium 699%99%93%
Copper99.9%99.9%93%
Iron99.9%99.9%99%
Lead99%99%85%
Manganese99%99%49%
Mercury92%91%92%
Selenium99%98%79%
Silver99.9%96.0%37%
Thallium99%98%91%
Zinc99.9%99.9%95%
Asbestos99%98%89%
Chlorine99%99%95%
Cyanide99.9%99.0%85%
Fluoride99%91%3%
PFOA/PFOS95.1%94.9%- -
Nitrate98%78%48%
Nitrite99%88%93%

❗️ Our Problem With ZeroWater’s TDS Removal Claims

We mentioned earlier that ZeroWater puts a big emphasis on the fact that its filters can remove TDS, or total dissolved solids, down to 0 in tap water.

We understand that many folks like knowing that they’re removing virtually all their water’s dissolved solids, and using the TDS meter for proof of the process.

The problem we have with this is that it has misled a lot of customers into believing that reducing TDS down to zero is absolutely essential, and that all dissolved solids are bad.

This isn’t true: there are some dissolved solids, like healthy minerals, for instance, that are good for us. But these minerals affect TDS, and because ZeroWater’s marketing is all about getting TDS down to 0, they get removed by the ZeroWater 5-stage filter.

Do we need healthy minerals? According to this 2017 review of 67 studies, various minerals in water have positive effects on digestion and skeletal health, and may even reduce the risk of coronary heart disease. However, folks who follow a healthy diet don’t need to obtain minerals from their drinking water because they’ll get plenty from their foods.

Plus, there are some contaminants that don’t affect TDS, including non-ionic compounds (disinfection chemicals, byproducts, and pesticides), dissolved gases like nitrogen, and particles like silt, clay, and microorganisms, which don’t dissolve in water and therefore aren’t classed as dissolved solids. All of these won’t be measured by a TDS meter. So, even if your water’s TDS is low, it might still contain certain harmful impurities.

That said, in ZeroWater’s case, there is an activated carbon component that should adsorb many of these other organic contaminants that aren’t detected by the TDS meter. This Drinking Water And Health evaluation found that disinfectant chemicals like chlorine, chlorine dioxide, and ozone “react readily with carbon” and are effectively adsorbed by an activated carbon media. The only way to know this for sure is with lab testing – something we plan to do soon.

We personally prefer to retain certain healthy dissolved solids in our water. We would much rather see evidence that ZeroWater filters can remove specific contaminants that we’re concerned about, instead of knowing that they can remove TDS as a whole.

Luckily, ZeroWater does have proof of contaminant removal, although we’d like to see its filters get tested to remove more impurities – some of its closest competitors have been tested to remove 200+ or even 300+ contaminants.

🔧Setup & Maintenance Considerations

We found that the ZeroWater filter systems were easier to assemble and set up than most similar systems.

The big advantage for us was that we didn’t have to prime or soak the filter, so we could just attach it to the unit and start filtering straight away.

ZeroWater’s 4-step assembly instructions are really simple to follow, and there are plenty of videos online if you need a visual demonstration.

On the other end, our maintenance commitments were worse than we expected, because the lifespan of the 5-stage ZeroWater filter is one of the worst we’ve seen for a gravity filtration system. It can filter just 40-50 gallons of water before it needs to be replaced.

Experts recommend that we aim to drink around half a gallon of water per day. Let’s say you have two people in your household, so you filter a gallon of tap water a day in the ZeroWater pitcher. That means it’ll last you around 40-50 days, or 5-7 weeks on average. We found that our filters lasted around 1-2 months, but some customers said their filters only lasted 2-3 weeks.

Assuming that we needed around 8 filters a year, we’d be spending around $110 annually on filter replacements, so at least the ongoing cost isn’t too bad.

Our tip: If you want to extend the lifespan of your ZeroWater filter, pre-filter your tap water through a cheaper system before you send it through the ZeroWater system. This will reduce some contaminants, so your costlier ZeroWater cartridge will have a longer lifespan.

The helpful thing about having a TDS test meter is that we could use it to monitor the filter’s performance. The manufacturer recommends replacing the filter when the TDS levels read 006.

You can also go off taste, since we and many other customers noticed a distinct taste to their water when a filter change was needed. But the TDS water tester is a more accurate way to determine the filter performance.

Brian installing the filter cartridge on the top reservoir of ZeroWater Glass Dispenser

🤔 Is the Zero Water Pitcher Or Dispenser Right for You?

In our opinion, the ZeroWater pitcher or dispenser is right for you if you want a way to remove total dissolved solids from your tap water without the expense, complex setup, and water waste of a reverse osmosis system.

As long as you’re happy to commit to changing filters as and when needed, the ZeroWater filter systems offer a simple, affordable, easy-setup, filtered drinking water solution. The annual cost of replacement filters is significantly cheaper than the cost of sustaining a bottled water habit. The Zero Water pitcher is cheaper than most other point-of-use filters, so it’s a good option in general if you want to keep your costs low.

When don’t we recommend the ZeroWater filters? Given that the 5-stage filter removes healthy minerals, we don’t recommend ZeroWater if you prefer to retain these minerals in your tap water. Instead, choose a carbon-based water filter pitcher that removes harmful contaminants while retaining minerals (most of them do).

Plus, the filter lifespan is pretty bad, so we don’t recommend ZeroWater to folks who want to enjoy filtered drinking water with mineral commitment or maintenance.

Finally, the ZeroWater filter has only been tested to remove just over 40 contaminants, while other water filter pitchers and dispensers we’ve reviewed have been tested to remove hundreds. If your priority is contaminant removal rather than TDS reduction, we suggest looking at some of the other pitchers and dispensers on the market.

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  • Brian Campbell
    President & CEO, CWS, CWR

    Brian Campbell, a WQA Certified Water Specialist (CWS) and Certified Water Treatment Representative (CWR) with 5+ years of experience, helps homeowners navigate the world of water treatment. After honing his skills at Hach Company, he founded his business to empower homeowners with the knowledge and tools to achieve safe, healthy water. Brian's tested countless devices, from simple pitchers to complex systems, helping his readers find the perfect fit for their unique needs.

4 thoughts on “ZeroWater Review: We Tested 3 of Their Water Filters”

  1. Avatar for Brian Campbell

    What are your thoughts on Ion-Exchange / Alkaline filtration? I started with Brita, then Zero Water, RainSoft (waste softener & reverse osmosis) the best by far in my opinion. And due to divorce my ex has the…so in my rental I am trying the ion / alkaline filtration. I am happy but also have many questions. Care to comment?

    1. Avatar for Brian Campbell

      Hey Jay, thanks for your comment. There are two types of ion exchange: cation and anion. Each process removes different substances, depending on ion charge. Learn more here https://waterfilterguru.com/what-is-ion-exchange/

      A water softener uses anion exchange to remove hard water minerals, protecting your home’s plumbing and water based appliances.

      A reverse osmosis system on the other hand pushes water through a semipermeable membrane, greatly reducing or removing essentially everything. It’s a good idea to pre-treat the water with a water softener before the RO if the water is really hard. This serves to protect the RO membrane and internal system components. Because reverse osmosis demineralizes water, you might want to consider remineralization to add healthy minerals back to the treated water which will increase pH and palatability.

      Let me know if you have any more questions!

  2. Avatar for Brian Campbell
    brianna catapano

    Would you prefer clearly filtered water pitcher over the zero water ? Also we just bought a house that has a Rain Soft reverse osmosis system installed under the kitchen sink. Do you know if this is a good water filtration system.

    1. Avatar for Brian Campbell

      It depends on what contaminants are present, and your own preferences. Depending on the contaminants, I would personally go for Clearly Filtered, but ZeroWater is a solid choice too. That said, if you already have a reverse osmosis system then an additional water filter pitcher would not be necessary (assuming the RO is working as intended)

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