Review: Culligan Under Sink Water Filters (US-EZ-1, US-EZ-3 & US-EZ-4)
Written by: Gene Fitzgerald // Last Updated: Sep 12, 2023
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As part of the EZ-Change (Easy-Change) series, Culligan offers 3 under sink water filters:
- The US-EZ-1 which is the most affordable of the 3 and for basic water filtration only.
- The US-EZ-3 for advanced filtration needs.
- And lastly, for premium filtration and thus the most expensive, the US-EZ-4.
Let’s find out if any of the 3 is worth purchasing!
Contents
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Culligan US-EZ-1 Under Sink Water Filter |
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| Price: | $ |
| Filter Process: | Activated Carbon |
| Filter Life: | 3,000 Gallons |
| Flow Rate: | 0.5 Gallons Per Minute |
| Annual Cost: | ~$20 |
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Overall Rating: 3.0/5.0
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Culligan US-EZ-3 Under Sink Water Filter |
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| Price: | $ |
| Filter Process: | Activated Carbon |
| Filter Life: | 500 Gallons |
| Flow Rate: | 0.5 Gallons Per Minute |
| Annual Cost: | ~$90 |
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Overall Rating: 3.5/5.0
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Culligan US-EZ-4 Under Sink Water Filter |
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| Price: | $ |
| Filter Process: | Activated Carbon |
| Filter Life: | 500 Gallons |
| Flow Rate: | 0.5 Gallons Per Minute |
| Annual Cost: | ~$160 |
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Overall Rating: 4.0/5.0
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Culligan US-EZ-1, US-EZ-3 & US-EZ-4 Under Sink Water Filters – All Specs
- Model: US-EZ-1, US-EZ-3, US-EZ-4
- Annual Maintenance Cost: ~$20-160
- Filter Media/Process: Carbon-Based
- Flow Rate: 0.5 gpm
- Filtering Capacity: 500-3000 gal
- WxHxD: 3.5″x11.875-14.325″x3.5″
- Water Temperature: 40-100 °F
- Water Pressure: 30-100 psi
- NSF Certifications: Standard 42, 53, 401
- Warranty: 2 Years
Culligan US-EZ-1, US-EZ-3 & US-EZ-4 – Key Features
Culligan US-EZ-1, US-EZ-3, and US-EZ-4 under sink water filters – all three systems feature a single carbon-based filter stage.
Being the most elementary, the US-EZ-1 is NSF Standard 42 certified to reduce chlorine and particulates class III. In other words: If all you care about is improved water aesthetics – think taste and smell – this filter may be absolutely sufficient. Each cartridge has a maximum filtering capacity of 3,000 gallons or up to 12 months.
FYI: Particulates class III have a size between 5 and 15 microns.
If apart from chlorine taste and odor and particulate, you also want to get rid of cysts (99.9%), turbidity (98.5%), lead (about 99.0%), and pesticides such as atrazine (94.1%) and lindane (98.2%), you should opt for the US-EZ-3. All reduction rates are according to NSF Standard 53. Its capacity is 500 gallons or a maximum of 6 months, whichever comes first. Obviously, this is less than what you get with the US-EZ-1, but no reason to worry about high maintenance demand. This won’t be the case.
For even higher filtration requirements, the US-EZ-4 is your best bet. In addition to all the impurities listed above, it’ll take care of chloramines, MTBE, mercury, chloroform, dozens of VOCs, perfluorinated chemicals (PFOA & PFOS), and so-called emerging contaminants for increased water safety (emerging contaminants include stuff like Phenytoin, Ibuprofen, and Bisphenol A). This has earned the unit 3 independent NSF certifications:
- Standard 42
- Standard 53
- Standard 401
Capacity: 500 gallons or 6 months.
Information overload? Check out this table:
| Contaminants | EZ-1 | EZ-3 | EZ-4 |
|---|---|---|---|
| Bad Tastes and Odors | Yes | Yes | Yes |
| Particulates | 99.9% (Class III) | 99.9% (Class I) | 99.9% (Class I) |
| Chlorine | 97.4% | 97.4% | 97.0% |
| Chloramine | – | – | 98.0% |
| Cyst | – | 99.9% | 99.9% |
| Turbidity | – | 98.5% | 98.0% |
| Lead | – | About 99.0% | 99.3% |
| Atrazine | – | 94.1% | Yes |
| Lindane | – | 98.2% | Yes |
| MTBE | – | – | 96.9% |
| Mercury | – | – | 96.6% |
| Chloroform | – | – | 99.8% |
| Emerging Contaminants (e.g. Ibuprofen, Phenytoin) | – | – | >95.4% |
| PFOA + PFOS | – | – | >95.8% |
| VOCs | – | – | Yes |
By the way, each Culligan under sink water filter is rated at .5 gallons per minute service flow rate which is rather low (more on this below). This is why each system comes with its own dedicated faucet.
Culligan Under Sink Water Filter Pros
There are a couple of things that we like about the Culligan US-EZ series and that is, firstly, the compatible head assembly which fits all replacement cartridges (RC-EZ-1, RC-EZ-3 & RC-EZ-4). So if all of a sudden you want water of higher purity you can easily upgrade your Basic or Advanced filter.
Secondly, the head features a simple twist on/off mechanism designed for convenience. This avoids the mess that comes with changing out traditional water filter cartridges. Instead, they can be replaced within seconds and without turning off the feed water supply – no need for buckets, towels, or wrenches.
Thirdly, each product is backed by a 2-year limited manufacturer warranty.
What’s more, installation is DIY-friendly so you can save money by not hiring a plumber.
A filter life indicator will let you know when to replace filters on the US-EZ-3 and US-EZ-4.
What Contaminants Are Being Removed?
- The US-EZ-1 removes chlorine taste and odor, and particulates.
- The US-EZ-3 removes chlorine, particulates, cyst, turbidity, lead, and certain pesticides.
- The US-EZ-4 removes chlorine, chloramine, particulate matter, heavy metals such as lead and mercury, cyst, turbidity, and all kinds of organic chemicals including pesticides, disinfection byproducts, industrial solvents, VOCs, PFOA and PFOS, and chloroform.
The Culligan US-EZ-1 – learn more on Amazon.com
The Culligan US-EZ-3 – learn more on Amazon.com
The Culligan US-EZ-4 – learn more on Amazon.com
Installation
The good news is that Culligan Easy-Change under sink water filtration systems come with everything you need for setup and operation.
What’s more, quick connect fittings and detailed DIY instructions make the installation much easier. So if you are a practiced do-it-yourselfer there’s probably no need for calling a plumbing professional.
The bad news is that if your kitchen sink or countertop does not have a pre-drilled hole (e.g. used for soap dispenser or water sprayer), you’ll have to drill one for the dedicated chrome faucet that is part of the system.
Please consider these instructions as a general guideline. Always make sure to check and follow your user manual before getting started.
Without going into full detail, here are some step-by-step instructions:
- Start by selecting a location for your faucet if you are not planning on using a pre-drilled hole. The included faucet fits any 9/16″ hole. Most pre-drilled holes are 13⁄8″ or 11⁄2″.
- First, drill a pilot hole using a 1/4″ drill bit. Then use a 9/16″ or 5/8″ drill bit to drill a hole completely through sink/countertop.
- Insert spout into faucet body and tighten using spout nut. Attach black rubber gasket onto threaded faucet stem.
- Insert faucet through hole and tighten from underneath using metal washer and white plastic stem nut. Hand-tighten only.
- Next turn off the cold water supply and drain all remaining water by opening the kitchen faucet.
- Install the feed water adapter. Use Teflon tape on threaded ends.
- Connect cold water line to existing faucet. Hand-tighten first, then snug nut with wrench.
- It’s time to mount the filter unit under your sink. Allow 1½” clearance below filter for cartridge replacements. Mount vertically.
- Connect the feed water adapter to the inlet port of the unit. Make sure to allow enough tubing to prevent kinking. Pro tip: Place a mark 5/8″ from both ends of the tubing. Push tubing into push fittings until mark is flush.
- Connect the filtered water faucet in the same manner. For the faucet connection, slide plastic compression nut over tubing followed by ferrule before placing insert into the end of tubing. Push tubing firmly into the end of the faucet stem. Hand-tighten compression nut. Then tighten another ½ turn using a wrench.
- Add battery into slot at faucet (not for EZ-1).
- Lastly, install the filter cartridge. Simply insert and turn arrow to locked padlock symbol.
- Turn on water supply. Check for leaks. Open drinking water faucet and flush unit for 10 minutes.
Video
The Package (Parts)
- Filter head with built-in bracket
- Filter cartridge
- Mounting screws
- Water supply adapter
- Lead-free chrome faucet with fittings
- Lithium battery (US-EZ-3/4 only)
- 1⁄4″ plastic tubing
- Cartridge change reminder sticker
Maintenance
The modular filter design allows for quick and easy filter changes and avoids the mess that traditional cartridges often make: Simply twist and pull down to remove old. Push up and twist to install new.
How often do you have to change filters?
The US-EZ-1 lasts for up to 3,000 gallons or 12 months, US-EZ-3 and US-EZ-4 for up to 500 gallons or 6 months. The built-in LED filter life indicator will let you know when it’s time for a replacement (US-EZ-3 and 4 only).
All in all, the annual maintenance costs are:
- Basic model – ~$20, which is really cheap
- Advanced model – ~$90, which is acceptable
- Premium model ~$160, which is a bit expensive
Manual
Here is a link to the official manual:
https://cdn.shopify.com/s/files/1/0531/5585/6541/files/US-EZ_Manual_Rev_H_2-2020.pdf?v=1628281414
NSF and Other Certifications
We have 3 NSF certifications:
- Standard 42 – all three systems
- Standard 53 – US-EZ-3 and US-EZ-4
- Standard 401 – US-EZ-4 only
Earlier Product Versions
To our knowledge, there are no earlier product versions.
Culligan Under Sink Filter Cons
- Half a gallon water flow per minute feels a little slow.
- The “chrome” faucet that’s included in the package is made from plastic except for its metal spout. We would have appreciated an all-metal faucet.
- A 1/2″ feed water adapter is part of the deal. However, if your home uses 3/8″ supply lines it won’t fit, so you will have to visit the local hardware store.
- Some customers reportedly had issues with leaks. One reason for this are the plastic connectors. You should seriously consider replacing them with brass. If on the other hand water leaks due to a cracked housing there’s really not much you can do.
- And finally, some customers complained about missing system parts and others said their water still retained its bad taste after filter installation.
Culligan US-EZ-1, US-EZ-3 & US-EZ-4 Review: Our Verdict + Best for
The Culligan Easy-Change Series is best for people who want an under sink drinking water filter that’s relatively simple to install, low in maintenance, and most importantly provides cleaner and better-tasting drinking water – all for an acceptable price.
Most customers seem happy with their purchase. Our verdict: 4 stars for the Premium US-EZ-4 EZ-Change Under-Sink Drinking Water Filter; 3.5 stars for the Advanced US-EZ-3 EZ-Change Under-Sink Drinking Water Filter; and 3 stars for the Basic US-EZ-1 EZ-Change Under-Sink Drinking Water Filter System.
If you want more serious water filtration, we definitely recommend the US-EZ-4 over the other two.
Our Rating in Detail:
- Filtration Performance: 4.0/5.0
- Filter Capacity (Life): 4.0/5.0
- Purchase Price: 5.0/5.0
- Annual Cost: 4.0/5.0
- Overall: 4.0/5.0
Comparison to Other Under Sink Water Filters
Let’s look at how well Culligan’s under sink water filters perform against the competition: The Clearly Filtered and the Epic Smart Shield.
Clearly Filtered 3-Stage |
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| Price: | $$$ |
| Filter Process: | Activated Carbon + Proprietary Blend |
| Filter Capacity: | 2,000 gal |
| Water Flow Rate: | Not Specified |
| Annually: | $440 |
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Overall Rating: 5.0/5.0
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Epic Smart Shield |
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| Price: | $ |
| Filter Process: | Activated Carbon Block |
| Filter Capacity: | 651 gal |
| Water Flow Rate: | 1.25 gpm |
| Annually: | $115 |
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Overall Rating: 4.5/5.0
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Culligan US-EZ-4 |
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| Price: | $ |
| Filter Process: | Activated Carbon |
| Filter Capacity: | 500 gal |
| Water Flow Rate: | 0.5 gpm |
| Annually: | ~$160 |
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Overall Rating: 4.0/5.0
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The Clearly Filtered under sink system (review here) is equipped with a 3-stage filter process. First is granular activated carbon. The next 2 stages are proprietary blends that remove forever chemicals, volatile organic chemicals, heavy metals, radiation, fluoride, arsenic, and a lot more. All in all, this under sink water filter has powerful filtration and can be used for lots of contaminants – it has been rigorously tested against NSF standards (53, 401, 42) for more than 200 of them, with excellent reduction rates.
Also, the Clearly Filtered has a 30-day satisfaction guarantee and a limited lifetime warranty. And you don’t need an extra faucet due to the inline design.
On the downside, the Clearly Filtered costs more to buy and maintain.
The Epic Smart Shield Under Sink Water Filter (read review) is an inline filter with a simple carbon block. The Epic has been certified by NSF to remove contaminants like pharmaceuticals, turbidity, VOCs, chloramine, chlorine, asbestos, lead, mercury, MTBE, BPA, and many more – powerful!
This under sink water filter is cheaper to purchase and maintain than the Clearly Filtered system and the US-EZ-4, which is the only comparable Culligan model in terms of filtration efficiency (the remaining models are noticeably weaker).
The Epic Smart Shield is also easy to install and maintain and all its parts are produced in the USA. The company has excellent customer support and offers a lifetime warranty and a seamless return policy. You can also recycle the filter cartridges through the company’s dedicated recycling initiative. The company will even give you a complimentary reward; when you return three used cartridges by mail, you get one for free.
Finally, the Epic has a flow rate of 1.25 gpm. This rate is slower than the Clearly Filtered’s, but significantly faster than what the Culligan systems can provide.
Bottom line: The Clearly Filtered is top-tier, and excels at removing a wide range of contaminants, though it costs more compared to the other under sink filters. The Epic filter is cost-effective while remaining useful against numerous water pollutants. This makes it more effective than all the Culligan models, even the US-EZ-4.
More Culligan Reviews:
This completes our review of Culligan’s US-EZ-1, US-EZ-3, and US-EZ-4 under sink water filters. If you have any questions please don’t hesitate to leave a comment below!
About the Author Gene Fitzgerald
Information provided on BOS is for educational purposes only. The products and services we review may not be right for your individual circumstances.
We adhere to strict editorial guidelines. Rest assured, the opinions expressed have not been provided, reviewed, or otherwise endorsed by our partners – they are unbiased, independent, and the author’s alone. We fact-check all content for accuracy. It is accurate as of the date posted and to the best of our knowledge.