What Do Culligan ZeroWater Filters Remove from Drinking Water?

Culligan with ZeroWater Technology is Culligan’s newer pitcher and dispenser line built around ZeroWater’s 5-stage filtration approach. In this unbiased filter review, we examine how the filters work, which contaminants Culligan with ZeroWater Technology filters are certified to reduce and why certification matters, and how to decide whether this type of filter is right for your tap water.

Update note: Culligan introduced a “Culligan with ZeroWater Technology” line of pitchers, dispensers, and replacement filters. We’ve updated this post to focus on the current Culligan with ZeroWater Technology line and moved legacy ZeroWater models out of the main review. Older ZeroWater pitchers and filters are now treated as legacy products and are not interchangeable with the newer Culligan with ZeroWater Technology systems.

Table of Contents:

1. How Do Culligan ZeroWater Filters Work?
2. When Should I Consider a Culligan ZeroWater Filter? 
3. What Are Culligan ZeroWater Filters Certified to Remove?
4. What Are They NOT Certified to Remove?
5. How Do I Know My Culligan ZeroWater Filter Is Working?
6. Frequently Asked Questions

How Do Culligan ZeroWater Filters Work?

According to the website, Culligan with ZeroWater Technology filters (referred to alternately as “Culligan ZeroWater filters” in this post) consist of five different filtration stages, including activated carbon mixed with KDF media, and ion exchange technology.[1] 

Culligan ZeroWater filters come in two popular formats:

• Pitchers
• Countertop dispensers

The Culligan ZeroWater filter includes activated carbon media mixed with KDF media, which is typically included to extend the life of the activated carbon media. In addition, the filter includes mixed bed ion exchange media, meaning that both anion and cation exchange resin is included in order to reduce a wide variety of contaminants.

Culligan’s ZeroWater Technology pitcher and countertop dispensers also feature the “Ready-Read,” an integrated TDS meter that displays a live reading of the total dissolved solids (TDS) of the water as it passes through the filter system. 

• What Does TDS Tell You About Water Quality?
  Low TDS is often equated with better water quality, but that isn’t necessarily the case. Neither high nor low TDS is a sure indicator of water quality because it’s only one parameter among the many that contribute to overall quality. The vast majority of minerals measured by TDS are harmless.
  
  High TDS readings (>500 PPM) indicate that the water sample has a high dissolved mineral content, but a high TDS reading does not necessarily indicate the presence of any specific contaminants. A more comprehensive water test can reveal both your TDS level and what dissolved minerals, metals and other constituents are in your water.

Culligan’s ZeroWater Technology Pitchers & Countertop Dispensers

All of Culligan’s ZeroWater Technology pitchers and countertop dispensers use the same filtration technology: the Culligan ZeroWater Technology filter cartridge described above. These products come in a number of different sizes:

• 7, 10, and 12 cup pitchers
• 22, 32, and 40 cup countertop dispensers

When Should I Consider a Culligan with ZeroWater Technology Filter System?

Because Culligan with ZeroWater Technology filters offer cost-effective, easy-to-use filtration systems certified to remove a variety of contaminants, they have become a popular choice for customers concerned about the quality of their water. Whether one of their filters is the best option for your home depends on your water's specific makeup. 

That’s why testing your water first is strongly recommended. 

Culligan posts the performance certifications for their products on their website, which lists the contaminants each filter is certified to remove.[2] If you’re concerned about contaminants that aren't listed in the certifications, you may want to investigate alternatives that fit your needs. 

Hunting for a filter system with the results of a water test already in hand allows you to better assess how effective each treatment system will be at meeting your needs. 

How Cost Effective Are ZeroWater Filters?

Culligan with ZeroWater Technology treatment systems and replacement filters are more expensive than the standard filter options from industry titans Brita and PUR. 

Some Things to Consider:

• According to the Culligan website, you should replace the filter once the Ready-Read TDS meter (included with the system) reads 006 or higher. Depending on your water’s quality, this may range from 8 to 40 gallons of use. 

• Additionally, it’s recommended you change the filter if you notice any difference in the taste or smell of your water. For water particularly high in TDS, filters may require replacement as often as every two weeks to make sure it works properly. This is something to consider when evaluating the overall cost of the treatment system.

Lastly, it’s important to test your water first to ensure this filter is the right choice for your home. If your primary concerns involve contaminants like lead, chromium, mercury, and PFAS, then the 5-stage filter could be a good choice. Make sure to review the certifications for each individual model since they vary.

What Are ZeroWater Filters Certified to Remove?

Below are the ZeroWater filters we’ve covered, along with the NSF/ANSI standards they’re certified to meet and the specific contaminants they reduce.

Culligan with ZeroWater Technology Filter - ZEROFXX (IAPMO)

• NSF/ANSI 42: Chlorine, Taste, Odor, and Zinc
• NSF/ANSI 53: Cadmium, Copper, Fluoride, Lead, Mercury, Total PFAS, and Hexavalent Chromium
• NSF/ANSI 401: Atenolol, Bisphenol A, Carbamazepine, DEET, Estrone, Ibuprofen, Linuron, Meprobamate, Metolachlor, Naproxen, Nonylphenol, Phenytoin, and Trimethoprim

Legacy ZeroWater 5-Stage Filter - ZR-001/ZF-201 (IAPMO)

• NSF/ANSI 42: Chlorine 
• NSF/ANSI 53: Lead, Mercury, PFOA/PFOS, and Hexavalent Chromium

What Are NSF, WQA, and IAPMO?

NSF, WQA and IAPMO are three different third-party organizations that grant certifications to water treatment devices that meet standards for performance and safety.

Do Culligan ZeroWater Filters Remove Minerals?

Due to the presence of ion exchange technology, Culligan with ZeroWater Technology filters are likely to remove various minerals from water, though their performance data sheets do not specifically mention the removal of minerals.

When it comes to minerals like calcium, magnesium, sodium, and potassium, it’s important to note that most people get their recommended daily intake primarily from food. While water can be a source of these minerals, especially when it comes from areas with naturally high mineral concentrations, it's generally a less significant contributor compared to diet. Drinking water with low mineral content isn’t harmful, but it won’t supplement your intake of these nutrients. 

Additionally, minerals tend to improve water’s taste and palatability. Distilled water, for example, tends to have a very flat, unpalatable taste. However, if the mineral content is too high, water can taste rather salty. Overall, while having these minerals in your drinking water can be beneficial, there aren’t specific recommended levels that apply universally. The ideal amount can vary depending on your diet and health needs, as well as personal preference.

Do Culligan ZeroWater Filters Remove Fluoride?

Yes, Culligan with ZeroWater Technology filters are certified for the reduction of fluoride in drinking water.

What Are Culligan with ZeroWater Technology Filters NOT Certified to Reduce?

Culligan with ZeroWater Technology filters have broader certifications than legacy ZeroWater filters, but they are still not a universal treatment system. Based on the current performance data sheet and IAPMO listings reviewed, the certified claims are limited to the listed NSF/ANSI 42, 53, and 401 substances. The current certification documents do not list reduction claims for contaminants such as:*

• Nitrate
• Arsenic
• Uranium
• Bacteria, viruses, protozoa, or other pathogens
• Chloramines
• VOCs
• Microplastics

*A filter may reduce some contaminants that are not listed on its certification documents, but uncertified claims should not be treated the same as third-party certified performance. If a contaminant is not listed on the product’s performance data sheet or certifier listing, consumers should not assume certified reduction.

What Does It Mean If a Filter Is Not Certified?

Because certifications are voluntary (and can be quite costly), filtration companies can choose to skip the process altogether and still make a product that works just fine. On the other hand, some companies may choose to skip certification because their product doesn’t work as well as they claim. As a result, the effectiveness of uncertified filters may vary widely from product to product.

Without Certifications, What Should be Removed Based on Technology? 

Though Culligan with ZeroWater Technology filters lack official certifications for many contaminants, the treatment technologies used in the filtration systems have proven effective against a variety of contaminants. 

Note: We strongly recommend performance testing a treatment device that isn’t certified. OR, if you tested your water before acquiring a filter, test your water again once you’ve broken in your filter.

Activated carbon should be effective at reducing:

• Additional organic contaminants like pesticides, pharmaceuticals, and disinfection byproducts (e.g. HAA5/HAA9)
• Some microplastics 
• Additional heavy metals
• Some larger pathogens like Cryptosporidium and Giardia*

*When certified for cyst removal or when absolute pore size is <1 micron

Ion exchange should be effective at reducing:

• Hardness minerals (cation exchange)
• Radium and strontium (cation exchange)
• Nitrate, arsenic, and uranium (anion exchange)

How Do I Know If My Filter Is Working?

The best way to determine if your Culligan with ZeroWater Technology filter is working is by testing your water, not to just rely on the provided TDS meter. You want to test your water before you invest in a Culligan ZeroWater filter so that you can get an idea of your tap water concerns. After all, you want to know what you’re trying to filter out, right?

Public Water Systems

If you’re a customer of a municipal or city water supply, you’ll have some slightly different concerns than someone using a private well. Unlike private well water, municipal water is treated and regulated.

We recommend the Advanced City Water test because it offers detailed analysis of common water health concerns plus advanced analysis including frequently detected disinfection byproducts from the addition of chlorine and chloramine in water treatment.

Private Well Owners

For someone on a private well supply, water quality is totally your responsibility. That includes exposure to bacteria and other common groundwater contaminants like nitrates, pesticides, and heavy metals. 

The Advanced Well Water test is a great way to get a baseline picture of any property served by a private well. It provides analysis of heavy metals, minerals, bacteria, hardness, nitrates, and many other parameters.

Remember: Testing your water through a certified laboratory is the best and easiest way to know whether or not a Culligan with ZeroWater Technology—or Brita, or PUR, etc.—filter is right for you. You might learn your tap water doesn’t need much treatment at all! 

Tap Score’s customer service team of water quality experts are always on call to help you every step of the way.

Frequently Asked Questions

Are ZeroWater and Culligan with ZeroWater Technology the same thing?

Not exactly. Culligan now owns ZeroWater, and Culligan now sells newer products under the Culligan with ZeroWater Technology name. These newer products are not the same as older legacy ZeroWater pitchers and dispensers. The most important practical difference is filter compatibility: new Culligan with ZeroWater Technology filters are drop-in filters for new Culligan-branded systems, while legacy ZeroWater filters are bottom-threaded and fit older ZeroWater pitchers and dispensers.

Which Culligan ZeroWater filter replacement do I need?

For newer Culligan with ZeroWater Technology pitchers and dispensers, look for the Culligan ZeroWater replacement filter listed as ZEROFXX on certification documents and ZEROF01 on the current product page. For older legacy ZeroWater systems, use the legacy ZeroWater replacement filter identified on the PDS as ZR-001/ZF-201. The two filter types are not interchangeable.

Do Culligan ZeroWater filters remove PFAS?

Yes. The newer Culligan with ZeroWater Technology line is certified for total PFAS, defined in the PDS as including PFOA, PFOS, PFHxS, PFNA, PFHpA, PFBS, and PFDA. 

Do Culligan ZeroWater filters remove lead?

Yes, the newer Culligan with ZeroWater Technology line has lead reduction certifications under NSF/ANSI 53. The exact claim depends on the product model and filter family.

Do Culligan ZeroWater filters remove fluoride?

The newer Culligan with ZeroWater Technology line is certified for fluoride reduction under NSF/ANSI 53.

Do Culligan ZeroWater filters remove pharmaceuticals and pesticides?

The Culligan with ZeroWater Technology line is certified under NSF/ANSI 401 for several emerging compounds, including examples commonly categorized as pharmaceuticals, pesticides, or related organic chemicals.

Do Culligan ZeroWater filters remove microplastics?

While ZeroWater’s legacy ExtremeLife faucet mount filters had a WQA NSF/ANSI 401 listing for microplastics, there is no evidence to support other Culligan ZeroWater pitchers or dispensers are certified to reduce microplastics, unless the specific model’s certification document lists microplastics.

Do Culligan ZeroWater filters remove TDS?

ZeroWater’s core technology is designed to reduce total dissolved solids, and the newer Culligan ZeroWater filter page says the product is guaranteed to reduce TDS by 99.9%. TDS reduction is not the same as contaminant-specific health certification, so it should be discussed separately from NSF/ANSI 42, 53, and 401 claims.

How often should I replace a ZeroWater filter?

The Culligan with ZeroWater Technology filter lists its lifespan at 20 gallons. Real-world filter life varies with source water chemistry and TDS, so ZeroWater/Culligan’s TDS meter guidance is still relevant.

Should I test my water before choosing a Culligan ZeroWater filter?

Yes. Certifications tell you what a filter is tested to reduce under standardized conditions, but they do not tell you what is in your tap water. Testing first helps determine whether you need a pitcher, faucet filter, under-sink system, reverse osmosis system, or a different treatment approach entirely.

Does Culligan owning ZeroWater affect certification integrity?

Not necessarily. Culligan ownership does not invalidate ZeroWater certifications. What matters is whether the exact product model and replacement filter are listed by an independent certifier such as IAPMO, NSF, or WQA. For the newer Culligan with ZeroWater Technology line, IAPMO listings are issued to Culligan International (ZeroWater) and describe third-party certification controls including sample testing, factory surveillance, quality-system review, and recognized laboratory testing. 

Still, shoppers should verify the exact SKU, filter, standard, and contaminant claim before comparing legacy ZeroWater and newer Culligan ZeroWater products.

Enjoyed our overview of Culligan ZeroWater filters? Check out our other unbiased filter reviews:

What Do Brita Pitchers Filter Out?
What Do PUR Pitchers Filter Out?
What Do Berkeys Filter Out?