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WQA & NSF Certified Water Filters

NSF and WQA Certified Water Filters for 2021

Considering NSF 53 certified water filter?

In this post, we explain the various NSF and WQA criteria used to certify modern water filtration systems and recommend a few top-rated water filter and water ionizer systems that have these accreditation.

Water filter manufacturers are similar to any other business. They need to sell their products and they're prone to exaggerating claims re. their own systems.

For example, the figures they give for water throughput rates and the life span of filters really only represent near-optimal conditions and will often not match your real-world experience.

However, the really important figures are those that concern a water filter's effectiveness in cleaning your water.

Manufacturers of water filters often boast claims like "99% lead reduction" or "95% of chlorine eliminated" - but how can you know whether to believe those numbers?

Luckily, the Water Quality Association (WQA) and NSF International are on it.

These two independent organizations examine and certify water filter systems and components throughout the world.

Water filter systems that are granted these logos have been certified deliver on their promise.

In this post, you will gain a more in-depth view into what these certifications mean and discover what the very best certified water filters sold online today are.

Best NSF and WQA Certified Water Filters

Here is a quick comparison of the best NSF and WQA certified water filters.

Aquagear Pitcher
  • Aquagear Filter Pitcher

  • NSF 53
  • Type:
    Filter pitcher
  • 5 stages
  • Reduces:
    Chlorine, chloramines, chemicals, fluoride, heavy metals
  • Lifetime warranty

PUR 3-Stage Faucet Mount
  • PUR Faucet Mount

  • NSF 53
  • Type:
    Faucet-mounted filter
  • 3 stages
  • Reduces:
    Chlorine, chemicals, heavy metals, sediment, rust, cysts
  • 1 year warranty

Aquasana OptimH2O water filter
  • Aquasana OptimH2O

  • NSF 53
  • Type:
    Under-sink reverse osmosis filter
  • 4 stages
  • Reduces:
    chlorine, chloramines, TDS, chemicals, sediment, heavy metals, fluoride, bacteria, viruses
  • 2 year warranty

Woder 10K-GenII Ultra High Capacity Water Filter
  • Woder 10K Under-Sink

  • NSF 42
  • Type:
    Under-sink chlorine & fluoride filter
  • 2 stages
  • Reduces:
    chlorine, fluoride, heavy metals, chemicals, sediment
  • 3 months warranty

Aquasana AQ-4000 water filter
  • Aquasana AQ-4000

  • NSF 401
  • Type:
    Countertop water filter
  • 3 stages
  • Reduces:
    chlorine, heavy metals, cysts, chemicals, sediment
  • 1 year warranty

iSpring RCC7AK
  • iSpring RCC7AK

  • WQA-certified
  • Type:
    Under-sink reverse osmosis filter
  • 6 stages
  • Reduces:
    chlorine, chloramines, TDS, chemicals, sediment, heavy metals, fluoride, bacteria, viruses
  • 1 year warranty

What is NSF Certification?

NSF Certified

NSF International provides accreditation for water filters that eliminate particular contaminants down to a specified level.

So what does 'NSF certified' mean to a water filter?

In short, an NSF-certified water filter is one that...

  • is structurally solid.
  • is constructed from approved components and plastics that will not leach into the water (such as BPA plastic).
  • is built from materials that will last a long time.
  • has approved labels which are 100% authentic.
  • has test results which are 100% the truth.

One more thing to note with NSF certification is that at times they will only relate to a certain part of the water filter system or to particular contaminants they reduce. Sometimes water filter manufacturers indicate that their systems are fully-certified in each facet when actually they just meet one safety standard.

There are many different NSF certifications. In this article, we’ll look at:

  • NSF 42
  • NSF 53
  • NSF 58
  • NSF 401

We’ll discuss each NSF standard and what it really means. We will also give examples of some of the best NSF certified water filters that meet all of these standards.

NSF 53 & NSF 58

NSF 53 & NSF 58

NSF 53 certified water filters meet the minimum requirements to reduce specific harmful water contaminants. These contaminants include:

  • Methyl Tertiary Butyl Ether (MTBE)
  • Cryptosporidium
  • Volatile Organic Compounds (VOCs)
  • Giardia

The NSF 53 Safety standard involves material security, structural integrity, and contaminates reduction capacity claims. It typically relates to water filters which use carbon dioxide as a way of filtration.

The elimination rate of water filters that meet this standard can vary. The NSF standard indicates that the water filter meets a minimum outflow. You’ll need to check with the filter's performance data sheet to know specific figures.

NSF 58 is a safety standard for lead and other general contaminants elimination. Rather than carbon water filters, it is applied to water filters which use a membrane similarly to reverse osmosis systems (RO).

According to our research, the ideal NSF 53 certified water filters are the following:

Aquagear Filter Pitcher


This certified Aquagear water filter pitcher is one we recommend to everyone. It's an NSF 53 water filter that removes lead and other contaminants. It's also NSF 42 certified (more on that later) for the elimination of chlorine.

This is an impressive filter pitcher that provides a degree of filtration which other jugs cannot match.

Additionally, it can remove fluoride from water. As a result, the filters are somewhat pricier than average. But if you are getting 53 and 42 NSF certification plus fluoride elimination, then it justifies the price.

PUR 3-Stage Faucet Mount

WQA & NSF Certified Water Filters

This faucet mounted filter meets NSF/ANSI Standard 53 for the reduction of contaminants like lead. It is a system that we highly recommend in our tap water filter guide.

This filter is another that is competitively priced and easy to set up and maintain. This is one of the cheapest NSF 53 licensed water filters selling today.

Aquasana OptimH2O

WQA & NSF Certified Water Filters

This NSF 53 water filter from Aquasana has a remarkable level of accreditation. It's tested and certified to meet NSF criteria 42, 53, 58, and 401. It is the only water filter that boast this level of certification.

Meeting such a  wide range of criteria makes this one of the best NSF certified water filters sold today.

The reason the Aquasana OptimH2O is able to remove so many impurities, and thus receive the many certifications, is because it is an RO filter. 

It combines carbon filtration and a high-rejection semi-permeable membrane to remove hundreds of contaminants from water including chemicals, heavy metals and microbes.   

The OptimH2O is an under-sink filter. Installation is not complicated, but it requires some DIY skills.

NSF 42

NSF 42

The NSF 42 standard signifies a water filter's ability to remove chlorine from water.

That said, NSF 42 certification does not cover harmful chlorine by-products. Like many criteria, water filters may meet or exceed this standard to various levels of effectiveness. This is a baseline for chlorine reduction.

Woder 10K Under-Sink

WQA & NSF Certified Water Filters

This is one of the best NSF 42 certified chlorine water filters around and is certified to remove large amounts of chlorine and lead.

It also carries the NSF 372 certification for having lead-free fittings and components. 

The Woder10K system is installed under the sink but is quite easy to set up. It’ll 3 years until you need to change the filter, making it very easy to care for.

This system also comes highly recommended on Amazon.

NSF 401

NSF 401

NSF standard 401 is a new standard. It rates the ability of a water filter system to reduce up to 15 specific contaminants. These contaminants have been identified by scientific studies to be found in most drinking water supplies.

It deals with unnatural compounds like soaps, herbicides, BPA, and pesticides. These are new and emerging pollutants that come from industrial farming and processes.

This standard applies to both carbon and RO water filter systems..

Aquasana AQ-4000W

WQA & NSF Certified Water Filters

The Aquasana AQ-4000W countertop system meets NSF standards 401, 42, and 53. In doing so, it eliminates a broad assortment of harmful contaminants.

It's also certified to the NSF P473 standard, which guarantees that it reduces PFOA and PFOS chemicals in water, a group of harmful manmade chemicals.

The AQ-4000W is a countertop unit that is simple to install and maintain.

Even better, this one is reasonably priced and is rated quite high in Amazon reviews.

WQA Certified Water Filters

WQA & NSF Certified Water Filters

The WQA Gold Seal Certificate demonstrates that a water filter system is ” assembled or devised from reliable elements, the specifications listed on the packaging are supported by evaluation data, and the item will work flawlessly under normal usage requirements."

This means that if a unit has WQA certification and claims it will remove 98% of lead from the water, then you can have confidence in the fact that it'll do exactly as stated.

An example of a WQA Gold Seal accredited system is the iSpring RCC7AK.

iSpring RCC7AK

WQA & NSF Certified Water Filters

This RO system is certified to remove an wide range of contaminants. RO is a healthy method of water filtration, and this is one of the best systems out there.

This particular system also includes an alkaline filter which adds healthy minerals back into the water. This provides better-tasting, contaminant-free water for your home.

NSF vs WQA Certification

Both NSF and WQA are organizations that test and certify products to agreed standards for quality and performance. 

The main difference is that NSF International deals with a wide range of consumer products while WQA specifically deals with water treatment products. 

But both organizations test and certify water filters to the same NSF/ANSI standards. So there's no difference between NSF and WQA certification. 

Both organizations are accredited by the American National Standards Institute (ANSI) as well as Standards Council of Canada (SCC).  

Certified vs. Tested To

When shopping for an NSF/WQA certified water filter, be on the lookout for manufacturers that play tricks on consumers by throwing the NSF or WQA name into products that are not actually certified. 

They'll often say that a certain filter has been tested to NSF 42, 53 or some other standard either by the manufacturer or a third party lab. 

But there's a big difference between tested to and certified. It may be true that the filter exceeds a specific NSF standard, but if it is not certified there's no guarantee of that. 

If you are specifically shopping for an NSF/WQA-certified water filter, make sure a particular filter is certified, and not just tested to a certain standard. 

Check the NSF directory to confirm the filter is actually certified. 

Final Thoughts 

Water Quality Association

We recommend searching for or inquiring about these certificates.

If a water filter system is certified in one of these ways, then you can believe its claims and relax in the knowledge that your drinking water is in safe hands.

That said, you’ll note that none of these certified systems claims 100 percent contaminant rejection rates.

The NSF and WQA criteria imply that a system meets minimum requirements under testing.

The manufacturers should have the documentation or results posted as public information. You can check this information to discover whether a certified water filter eliminates 99% of chlorine or 90%, for instance.

Also, note that these two organizations aren't the only authorities offering independent testing of water filters. They're definitely the most recognized and standard but there are other certifications that can be trusted. Some smaller manufacturers get certification from smaller independent labs, for example.

Most of the famous makers of water filtration systems (iSpring, APEC, Aquasana, Aquapure, etc) all will produce only units that are NSF and WQA certified.

Be careful if you have a small budget and ensure you find some kind of certification/accreditation, be it in the big names or a more prominent laboratory.

Ed Carmichael

About the Author Ed Carmichael

Ed is a water specialist in Tampa, FL. He built to help his friends and family learn about DIY solutions to common water quality issues in the home.

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