Best Water Purifiers for Home Use – Reviews & Buying Guide 2021

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Water purifiers come in all forms and sizes. Each type has its own pros and cons. Some have a higher initial price tag, but are more cost effective in the long run. Others are portable, but at the same time limited in their water storage volume.

Yet others are easy to install and use, but mainly improve water aesthetics and barely touch the more stubborn and more harmful contaminants.

The point is, although every water purifier gives you access to water that is better tasting and somewhat cleaner and safer, choosing one perfectly suited to your needs requires careful consideration.

Don’t worry; we will help you make the right buying decision. Let’s find you the best water purifier!

On This Page You Will…

No Time to Read? Check Our Best Water Purifier Toplist!

ModelOur RatingPriceTypeNSFAnnual CostWarranty
AquaTru Countertop Reverse Osmosis system

#1 Countertop RO Water Purification System: Aquatru

Read Review
$$Countertop Reverse Osmosis42, 53, 58, 401, P473~$100-1201 Year
Use our discount code BOSAquaTru at checkout and get 5% OFF!
Clearly Filtered Water Purifier Pitcher

#1 Water Purifier Pitcher: Clearly Filtered

Read Review
$Pitcher42, 53, 244, 401, P473$150Lifetime
Aquasana OptimH2O Under Sink Reverse Osmosis System

Under Sink RO System: Aquasana OptimH2O

Read Review
$Under Sink Reverse Osmosis42, 53, 58, 401, P473$180-2202 Years
Clearly Filtered 3-Stage Under Sink Water Purifier

Regular Under Sink Water Purifier: Clearly Filtered 3-Stage

Read Review
$$Under Sink42, 53, 401$400Lifetime
SpringWell CF4 whole house water purifier

Whole House Purification System (Tap Water): SpringWell CF

Read Review
$$$Whole House-$40Lifetime
SpringWell WS4 whole house well water purifier

Whole House Purification System (Well Water): SpringWell WS

Read Review
$$$$Whole House--Lifetime
We recommend pairing the SpringWell WS4 with the CF4 (row above) for a more complete treatment.

The Best Water Purifiers by Type

1. Countertop Reverse Osmosis System: AquaTru Review

One of the best water purifiers: The AquaTru countertop reverse osmosis water purification system. NSF Certified to remove up to 99.99% of 82 different water contaminants, your filtered drinking water will taste great and be clean and healthy.

What’s more, the AquaTru is installation-free – great if you’re a renter or not handy with tools. Maintenance? Effortless and low-cost. 4.5 stars!

Make sure to use our discount code BOSAquaTru at checkout and get 5% OFF!

AquaTru Countertop Reverse Osmosis system


Type:Countertop RO
NSF:42, 53, 58, 401, P473
Warranty:1 Year

Our Rating


  • AquaTru countertop RO system can be put together in no time without any plumbing or drilling.
  • Easy to use.
  • NSF certifications: Standards 42, 53, 58, 401, and P473. Guarantees effective contaminant removal rates, like chlorine (96.6%), lead (99.1%), chromium 6 (97.2%), cyst (99.99%), BPA (99.0%), PFAS (97.5%), VOCs (most above 99%), bad taste and odor.
  • 4 stage filter process combines sediment and activated carbon filtration with reverse osmosis water purification.
  • System purifies 1 gallon in 10-15 minutes. Eliminates long waiting times.
  • Built-in water pressure pump increases productivity while dramatically reducing water wastage.
  • Comfortable one-button water dispensing.
  • Clean water tank can be removed from system, for example for cooling in refrigerator.
  • Wastewater collects in second tank to be discarded.
  • Tritan plastic material is BPA and BPS-free.
  • Filter elements need annual/biannual replacement. RO membrane lasts up to 2 years.
    • Replacement process couldn’t be easier.
    • LED on front panel let’s you know when to replace which element.
    • Cost: ~$100-120 per year which is surprisingly affordable.
  • 1 year warranty.


  • A handful of people had issues with leaking or malfunctioning units.

→ Read: AquaTru Fully Reviewed

2. Water Purifier Pitcher: Clearly Filtered

Water filter pitchers are probably the most popular type of home water purifier. They can be assembled in under 5 minutes, they’re small and thus portable, they’re handy, and most important for many they’re super low-cost.

Our go-to water purifier pitcher is the Clearly Filtered. That’s because it has been tested to remove more contaminants than any of its competitors and the water it provides simply tastes great.

Clearly Filtered Water Purifier Pitcher

Clearly Filtered Pitcher

Type:Purifier Pitcher
NSF:42, 53, 244, 401, P473

Our Rating


  • Made in USA.
  • The only water filter pitcher successfully tested to 5 different NSF standards: 42, 53, 244, 401, and P473.
  • Uses granular activated carbon and other filter media (not disclosed) to remove 230+ contaminants that could be lurking in you water supply, such as: Chlorine (99.9%), chloramine (99.9%), volatile organic compounds (99.7-99.9%), arsenic (99.6%), lead (99.5%), chromium 6 (96.9%), fluoride (~98%), some microorganisms (99.9%), pesticides (99.9%), and PFOS + PFOA (99.6%).
    • Tested by independent lab, so filtration effectiveness for highest drinking water quality is guaranteed.
  • Healthy minerals remain in water.
  • 10-cup water storage capacity is enough for family use.
  • Removable lid makes refilling much easier.
  • Tritan plastic is 100% BPA-free.
  • Initial assembly goes quick and easy.
  • Long lasting filters (100 gallons or an average of 4 months) save you from frequent replacements.
    • Annual cost: Approx. $150 but you can sign up and buy in bulk to receive discounts.
  • Covered by 30-day satisfaction guarantee + lifetime warranty.


  • Relatively expensive.
  • A few people complained about slow filtration and filters clogging ahead of time. We haven’t experienced this yet.

→ Read: Clearly Filtered Pitcher Fully Reviewed

3. Under Sink RO System: Aquasana OptimH2O

Next in our water purifier reviews: The Aquasana OptimH2O. In our opinion, it’s the #1 under sink reverse osmosis purifier in 2021. It’s not only capable of removing dozens upon dozens of potentially harmful pollutants from your water, it also enriches it with healthy minerals!

Aquasana OptimH2O Under Sink Reverse Osmosis System

Aquasana OptimH2O

Type:Under Sink Reverse Osmosis
NSF:42, 53, 58, 401, P473
Warranty:2 Years

Our Rating


  • Affordable.
  • According to lab reports, the three purification stages – activated carbon, RO membrane, catalytic carbon – can remove more than 88 different contaminants from water.
    • Process has been tested and certified against NSF standards 42, 53, 58, 401, and P473.
    • Some of the removed contaminants are chlorine/chloramine, lead, mercury, chromium, fluoride, VOCs, all kinds of chemicals, PFAS, and overall TDS.
  • Remineralization stage adds calcium, magnesium, and potassium back into the water. This improves taste and alkalinity, and the minerals add to your daily recommended intake.
  • Daily water purification capacity is not the highest but sufficient for family use.
  • Choose between 3 faucet designs to match your kitchen decor: Chrome, brushed nickel, oil-rubbed bronze.
  • Aquasana OptimH2O water filter system was designed with DIY installation in mind. All bits and pieces as well as step-by-step instructions are included in the package.
  • Replacing the filters/membrane is simply. They twist on/off. Fittings are quick-connect.
    • Cost: Roughly $180-220 a year which is acceptable but more than what you pay with some other RO units. You can subscribe for discounts.
  • Aquasana promises 90-day money-back guarantee for risk-free trial.
  • Warranted for 2 years.
  • Great customer support.


  • A few issues with leaks.
  • Especially the water dispensers could to with a quality upgrade.

→ Read: Aquasana OptimH2O Fully Reviewed

4. Regular Under Sink Water Filter: Clearly Filtered 3-Stage

You like under sink water purifiers but you’re no fan of reverse osmosis? We have the perfect system for you: The Clearly Filtered 3-Stage. Just like the Clearly Filtered pitcher, it’s thoroughly tested to reduce far more than 200 contaminants giving you access to drinking water that’s healthy and refreshing.

Simply put, it’s the best water purifier to be installed under a kitchen sink. 5 stars!

Clearly Filtered 3-Stage Under Sink Water Purifier

Clearly Filtered 3-Stage

Type:Under Sink Purifier
NSF:42, 53, 401

Our Rating


  • Made in USA.
  • According to independent NSF standard (42, 53, 401) testing, removes chloramine, chlorine, heavy metals, disinfection byproducts, fluoride (99.5%), PFAS (99.9%), herbicides and pesticides (up to 99.9%), more than one hundred volatile/semi-volatile compounds (99.9%), and more.
  • 3-stage water purification process:
    1. Granular coconut shell activated carbon.
    2. Filter media blend.
    3. Proprietary filter media targeting fluoride and arsenic.
  • Features stainless steel hoses rather than plastic for durability.
  • Quick, non-permanent DIY installation. No need to hire a professional and great for renters.
  • Modular water filters are easy to replace every 2,000 gallons or 12 months.
    • No need to turn off the feed water supply thanks to built-in shut-off valves.
  • You can test the under sink water purifier for 30 days. Return if you’re not satisfied for a full refund.
  • All Clearly Filtered products are warranted for lifetime.


  • Not exactly cheap.
  • Reduces water pressure by 15-25 percent.
    • Remember: Thorough filtration takes time.

→ Read: Clearly Filtered 3-Stage Fully Reviewed

5. Whole House Water Purification System (Tap Water): SpringWell CF Series

Our favorite whole house water filter for homes on tap water in 2021 is the SpringWell CF4. Applying a mixture of catalytic carbon and KDF filter media, it turns even the nastiest tap water into clean, odorless, and great-tasting water suited for cooking, drinking, and household use.

SpringWell CF4 whole house water purifier

SpringWell CF

Type:Whole House Water Filtration System

Our Rating


  • Suited for both municipal water containing chlorine and chloramine.
    • SpringWell guarantees reduction below the detectable level for 1 million gallons of water or 6 years of use.
  • Small pre-filter traps sediments. Improves water aesthetics and protects the large media tank from clogging.
  • Catalytic carbon adsorbs all kinds of chemicals, disinfectants, disinfection byproducts, VOCs, …
  • KDF filter media reduces heavy metals and any remaining chlorine. Also controls the growth of bacteria, algae, and fungi.
  • 3 purifier system sizes:
    • CF1 for homes with 1 to 3 bathrooms. 9 gallons per minute service flow rate.
    • CF4 for any home with 4 to 6 bathrooms. 12 gpm flow rate.
    • CF+ for 7+ bathroom households. Supplies 17 gallons of filtered water per minute.
  • Easy to install for a whole house water filter. Shouldn’t be a problem if you’re handy around the house.
    • Bypass valve already build in.
    • Detailed installation instructions with images.
  • The only required maintenance is changing the sediment pre-filter once or twice a year. Cost: ~$40 annually.
  • Full money-back guarantee for six months.
  • Limited lifetime warranty.


  • Fittings are plastic. We would have preferred metal.

→ Read: SpringWell CF Fully Reviewed

6. Whole House Water Filter (Well Water): SpringWell WS Series

The SpringWell CF series reviewed above is for homes receiving their water from the local municipality. For homes on well water, the SpringWell WS whole house purifier series is our preferred choice. It takes care of iron, manganese, and hydrogen sulfide content.

By the way, feel free to pair the WS with the CF series if you shock your well regularly or if the water also contains chemicals, organics, or metals other than iron and manganese. This way, your water will be much safer for consumption and taste better.

Please note: You can find all details about the SpringWell CF above.

SpringWell WS4 whole house well water purifier

SpringWell WS

Type:Whole House Water Filtration System

Our Rating


  • Uses air injection oxidation + greensand filtration to remove ferric & ferrous iron (up to 7 ppm), hydrogen sulfide (up to 8 ppm), and manganese (up to 1 ppm). Greensand also helps with radium and arsenic.
    • No more rotten egg smell.
    • Eliminates iron staining.
    • Greatly improves water taste.
  • 2 system sizes to choose from:
    • WS1 for 1 to 4 bathrooms at 12 gallons per minute water flow.
    • WS4 for 4+ bathrooms. 20 gpm service flow rate.
  • As easy to install as any other whole home water purifier.
    • Bypass valve + illustrated installation guide included.
  • Purification process is fully automated: Daily reset of air pocket and periodic backwashing of greensand media.
    • Only need to program the digital control head once. Can be done via app if you want to.
  • Virtually maintenance-free. Greensand lasts 18 to 25 years.
  • Covered by SpringWell’s 6-month satisfaction guarantee and lifetime warranty.


  • Fittings are plastic.

→ Read: SpringWell WS Fully Reviewed

7. Gravity Purifier: Berkey

Berkey deservedly is the most popular gravity water filter brand currently on the market. Most importantly, Berkey purifiers which come in different sizes are highly effective at removing a broad range of water contaminants. On top of that, they’re easy to assemble, use, and maintain. Do we have your attention?

Berkey Gravity Water Purifier

Big Berkey

Type:Gravity Water Filter System

Our Rating


  • Black Berkey purifier elements trap impurities down to the submicron level: Chlorine & chloramine (below detectable levels), cadmium (>99.7%), chromium-6 (>99.85%), lead (>99.9%), pharmaceuticals (>99.9%), THMs (below detectable levels), pesticides and VOCs (below detectable levels), sediments, turbidity, taste and odor, and microorganisms (viruses >99.999%, bacteria >99.9999%, cyst).
    • Tested to NSF 53 standards.
    • Healthy minerals are preserved.
  • Optional Berkey PF-2 filter elements are for fluoride and arsenic removal.
  • 7 different gravity filter sizes to meet your water needs.
    • Larger means faster filtration and larger storage tank for filtered water.
    • Big Berkey version is the most popular. Great for family use.
  • Durable 304 food-grade stainless steel.
  • Rubber casket under bottom tank prevents surface scratching.
  • Setup is child’s play.
  • Each Black Berkey element lasts approx. 3,000 gallons of water. Average replacement frequency: 3 years. Average annual replacement cost: $40. Huge time and money saver.
  • Covered by lifetime warranty.


  • Frequent filter re-priming may be necessary.
  • Gravity purification does not stop once the lower tank is full. Be careful not to overfill.
  • You have to lift the upper holding tank to check how much purified water is left.
  • Issues with leaking dispensers and slow flow due to negative pressure.
  • At $120 a year on average, the fluoride filter addons seem expensive.

→ Read: Big Berkey Fully Reviewed

8. Water Purifier Bottle: Clearly Filtered

As far as we know, Clearly Filtered water purifier bottles are the best in terms of contaminant reduction rates and purified water taste. And the quality of the bottles is outstanding, too. So if you want clean drinking water when you’re out and about, you should seriously consider this option.

Clearly Filtered Insulated Stainless Steel Water Purifier Bottle

Clearly Filtered Insulated Stainless Steel Bottle

Type:Filtering Bottle
NSF:42, 53, 401

Our Rating


  • 3 bottle types:
    1. Insulated stainless steel – Most durable, keeps 20 ounces of water cool for up to 24 hours.
    2. Medical grade, BPA-free Tritan plastic – Can hold up to 24 ounces.
    3. Borosilicate glass – 20 ounces water storage capacity. Glass requires careful handling!
  • Each type uses Clearly Filtered’s proprietary Affinity filtration technology (activated carbon + adsorption filter media) to remove 220+ contaminants from tap water, including chlorine and chloramines, fluoride, herbicides, and lead.
    • Tested to NSF/ANSI standards 42, 53, and 401.
  • All materials are BPA, BPS, and phthalate-free so that nothing leaches into your water.
  • Bottles and filters are built in USA.
  • One filter cartridge is rated at 25 gallons (equals 130-160 fill-ups) or 6 months. Cost: $25 each.
  • Mouthpiece and filter straw need to be hand-washed every once in a while.
  • Full money-back guarantee for the first 30 days after purchase.
  • Lifetime guarantee.


  • Not the cheapest filter water bottles on the market but worth their price in our opinion (certainly more affordable than buying bottled water).
  • Some people find it a bit difficult to drink out of the bottles as you have to apply strong suction to get a good flow.
    • Filters become less restrictive pretty quickly.
  • Leaking? Only if the silicone ring inside the lid is doesn’t sit right.
  • You have to hold the bottles upright while drinking. Otherwise the water won’t actually flow through the purifier.
  • Stainless steel bottle isn’t dishwasher safe

→ Read: Clearly Filtered Bottles Fully Reviewed

9. Portable: SteriPEN Ultra Handheld UV Water Purifier

Planning a backcountry adventure? Want to make sure that the drinking water on your next field trip is microbiologically safe? In our opinion, the SteriPEN Ultra is the most advanced handheld ultraviolet water purifier that effectively kills 99.9% of bacteria, protozoa, and viruses.

SteriPEN Ultra Handheld UV Water Purifier


Type:Portable UV

Our Rating


  • Small and lightweight. Ideal for backpacking, hiking, and camping.
  • Tested by the WQA against U.S. EPA standards.
  • UV light changes DNA of bacteria, protozoa (including giardia and cryptosporidium), and viruses so they can’t reproduce.
  • Simple to use: Remove lid, push start button, and submerge UV lamp in water and stir. Water is ready when LED screen shows smiley (after 48 or 90 seconds).
  • Battery lasts 13 gallons and can be recharged via USB.
  • Neoprene pouch and USB cable are included.
  • 3-year limited warranty for peace of mind.


  • Some reviewers said their SteriPEN just died after a short time.
  • Cloudy or sediment-laden water could lower effectiveness of UV purification.

10. Faucet Water Filtration System: Brita Complete FF-100

Faucet water purifiers connect to the kitchen faucet or a bathroom tap and give you access to filtered drinking water right then and there. Our recommendation: The Brita Complete FF-100. It’s by far the best in terms of contaminant reduction rates.

Brita Complete FF-100 Faucet Water Purifier

Brita Complete FF-100

NSF:42, 53, 401
Warranty:1 Year

Our Rating


  • Filters the most common drinking water contaminants like sediment, lead, asbestos, VOCs, chlorine, and BPA.
  • Tested and certified against NSF Standard 42, standard 53, and standard 401.
  • You can switch between purified and plain water to extend filter life.
  • 1-click install with faucet adapters included.
  • Each filter cartridge lasts 100 gallons or up to 4 months, whichever comes first.
    • Easily replaceable.
    • No need to remember date of next replacement thanks to filter change indicator.
    • Pricing is reasonable.
  • Brita has its own water filters recycling program.


  • Leaking.
  • Flimsy faucet connection might cause filter to fall off.
  • For standard-sized faucets only.

11. Water Distiller: Nutriteam Megahome MH943SBS

Everyone who’s been in the home water purification industry long enough knows Megahome water distillers by Nutriteam. The company has been around for more than 20 years and the MH943SBS is their flagship. Learn more below!

Nutriteam Megahome MH943SBS Water Distiller

Nutriteam Megahome MH943SBS

Warranty:1 Year

Our Rating


  • 580 Watts distill 1 gallon of water in 5½ hours. All you have to do is fill the 304 stainless steel kettle and hit the start button.
    • Monthly electricity cost when distilling 1 gallon of water per day: $10-15. Much cheaper than buying bottled water.
  • The distilled water cannot possibly touch any plastic parts which avoids recontamination.
  • Activated carbon filter sachets adsorb any volatile chemicals that might have escaped the boiling chamber.
    • 6-month supply included.
  • Water collector is made from glass which looks better than plastic and provides for pure taste.
  • UL approved for highest safety standards.
  • 1 year warranty.


  • There is no off switch. The distiller shuts of automatically at the end of the boiling process. This may cause burned deposits at the bottom of the kettle which are difficult to clean.
    • Using a timer switch and setting it to 5 hours is the best solution in our opinion.

→ Read: Megahome Water Distiller Fully Reviewed

12. Shower Water Purifier: Aquasana AQ-4100/4105

The Aquasana AQ-4100 respectively AQ-4105 is our go-to shower water filter. It has shown to remove most of the chlorine for as much as 10,000 gallons of water and, according to Aquasana, also reduces chloramines, lead, mercury, iron, hydrogen sulfide, and volatile substances like pesticides.

Aquasana Shower Water Purifier

Aquasana AQ-4100/4105

Warranty:1 Year

Our Rating


  • Aquasana promises noticeably softer and more moisturized hair and skin + better air quality inside the shower.
  • KDF-55 (copper-zinc blend) reduces chlorine and balance water pH. Activated carbon further removes chlorine as well as synthetic chemicals.
    • NSF standard 177 certification for chlorine reduction.
  • 4 different versions available:
    • With massaging handheld wand
    • With massaging handheld chrome wand
    • With a massaging head
    • Filter only
  • Purified water flow rate is 2.5 gpm which is pretty standard.
  • 100% BPA-free materials.
  • Upflow design prevents clogging.
  • Doesn’t lower shower head height for comfortable standing.
  • Very easy to install.
  • One filter lasts 10,000 gallons or 6 months so no frequent replacements needed. Also, filter replacements are quick and easy, no tools required.
  • 90-day satisfaction guarantee + limited 1-year warranty that covers defects in materials or workmanship in manufacturing. Replacement cartridges are warranted for 6 months.


  • Replacement water filters are quite expensive.
  • Vinyl hose is too stiff. Better go with chrome flex hose.
  • A few users had issues with leaks.
  • Filter nozzle is too short to accommodate large shower heads.

→ Read: Aquasana Shower Filter Fully Reviewed

Buyer Guide – Things to Consider When Shopping for the Best Water Purification System

Which purifier is best for you? Well, it turns out that there’re several things you need to consider when shopping:

Water Purifier Type & Purification Process

Talking about water purifiers is like talking about cars. There exist many different types, each with their own advantages and disadvantages. There are water filter pitchers, portable/gravity water purifiers, whole house systems, under sink and counter top water purifying units, filtered water bottles, shower water filters, water distillers, faucet water purifiers, and not to forget reverse osmosis systems.

Which type is best suited for your needs depends on your individual situation and preferences (we’ll discuss each type further below).

The same goes for the specific water purification process/media a system applies. For example, one countertop water purifier may use an ultrafiltration membrane, while another uses activated carbon and UV light treatment.

Bottom line: We recommend you look around on BOS for a bit to learn more about the various options you have for home water purification. Or if you like things to happen fast, check the list with our favorite products above. We’re absolutely certain that there’ll be something of interest to you.

NSF Certifications

When reviewing products, we like to rely on NSF testing and certifications by independent laboratories which guarantee that a water purifier does indeed perform as advertised. In a nutshell:

  • NSF standard 42 tests for chlorine reduction and water aesthetics.
  • Standard 53 was established for contaminants with health effects – think heavy metals.
  • Standard 58 is for RO systems specifically.
  • NSF standard 244 covers testing for the reduction of bacteria and viruses.
  • Standard 401 looks at so-called “emerging compounds“ not yet regulated by the EPA.
  • And lastly, protocol P473 for PFAS which you’ve might already heard of (not to be joked about).

Purifying Capacity (Flow Rate + Storage)

Depending on which purifier (type) you choose, you’ll get a larger or smaller purification capacity, meaning purified water flow rate and/or storage capacity.

Pro tip: If you don’t like to wait for clean water being produced when you’re thirsty, make sure that a system can meet your daily demand even at times of peak consumption before you buy it.

Installation + Maintenance

Again, cost and required work for installing and maintaining your new water purifier highly depends on what type it is. Simply put, a whole house water purification system is more difficult to set up than a pitcher.

We made sure to include information regarding installation and maintenance with each product reviewed above.

Trial Period & Warranty

We prefer products that come with an extended trial period and a lifetime warranty which got you covered in case anything goes wrong.


Pretty obvious, but larger and more complex water purifiers are usually more expensive. By the way, you should not only take into account the initial cost for purchase and installation but also for maintenance, meaning replacement filter cost.

More on Water Purification Systems

What is a Water Purifier?

A water purifier is any device designed for removing undesirable chemicals, organic contaminants, suspended or dissolved solids, and gases from water.

Thereby, most water is purified for drinking purposes. Others applications include chemical, medical, and industrial.

Common water purification methods are filtration, distillation, sedimentation, chlorination, ultraviolet light radiation, and flocculation.

Do You Really Need a Water Purifier?

Whether or not you need a water purifier depends on if, which, and how many contaminants are present in your water supply. That said, water purification is not only about water tasting or smelling unpleasant – far from it. Most dangerous water contaminants are invisible to our senses. One infamous example is lead, a neurotoxin that is too small to see, taste, or smell.

But how do you know if the water in your home is drinkable? Through testing! Or, if you’d prefer to not spend any money on this you can check the free water quality report for your local utility on this page or this link – provided that you’re not on a small or your own private well.

If the latter is the case, your best option is to send a direct sample to an independent laboratory. Alternatively, you could buy a small test kit which should give you a rough idea of what you are facing.

Knowing what’s in your water is the only way to make an informed buying decision and choose a water purifier capable of dealing with all or at least the majority of contaminants you’re exposed to.

Causes of Water Pollution

There’s natural and there’s man-made water pollution. Sources for the former include volcanic activity, algae blooms in hot weather, storms, and earthquakes.

Human-induced water pollution can be categorized in:

  • Groundwater pollution – Contamination are released into the soil which eventually leach into an aquifer and may render it unusable. What’s more, groundwater provides more than 40 percent of water used for irrigation in the US. Thus, the contamination will likely affect other areas of our lives, as well.
  • Surface water pollution – Our oceans, lakes, ponds, wetlands, streams, and rivers are surface waters. And a large proportion of them are in poor condition, at least in the United States. Most common are elevated phosphorus and nitrogen levels responsible for algae blooms that lead to oxygen depletion which in turn affects wildlife and public health. Both phosphorus and nitrogen are agricultural runoff basically. Municipal and industrial waste do their part to contribute to the problem.
  • Marine pollution – Most marine pollution originates on land. For one, chemicals and heavy metals are carried by our waterways from farms and industrial plants out to sea. Not to speak about all the (micro-)plastic swirling in our oceans today.
  • Point source pollution – Point source pollution means it originates from a single source, like a sinking oil tanker.
  • Non-point source pollution – Non-point source pollution has diffuse causes, for example stormwater runoff. There’s not a single culprit or it’s extremely difficult to identify.

The Different Types of Water Purifiers/Purification, How They Work & Their Benefits

Like we said, there’s more than one type of water purifier. Each works a little different and therefore has its own benefits…


Water purifier pitchers rely on gravity to force feed water through a filter element. They’re small, handy, and portable. They don’t require installation. And, most importantly, they’re cheap. No wonder that they’re the most popular kind of water purifier!


Just like pitchers, this water purifier type uses gravity to channel water to one or more filter elements. The water purification itself is usually very thorough providing you with drinking water of the highest quality.

Portable Filtering (Straws, Pumps, Gravity Bags…)

A water purifier pitcher is portable, and so are gravity systems. However, when we’re talking about portable water purifiers we usually mean those designed for outdoor use: Backpacking, hiking, camping, or traveling. Preppers also like portable systems to be prepared in case of an emergency.

A reliable unit provides drinking water free from bacteria, protozoa, and possibly viruses.

Whole House Water Filters

As the name suggests, whole house water purification systems supply your entire home. Bathroom taps, showers, kitchen faucet, home appliances – you’ll have purified water at every outlet.

Most common are catalytic or activated carbon systems.

Under sink

They get installed under your kitchen sink and provide purified drinking water at a single outlet. Most are effective at removing a wide range of contaminants, while still being affordable. Easy installation, simple maintenance, and convenient use are why people love under sink water purifiers.


A standard countertop water purifier gives you access to clean water straight at your kitchen sink without the need for proper installation. They can be hooked up to any standard-sized faucets in less than 5 minutes. More benefits: Portable, convenient, affordable.


A purifying bottle is great if you want healthy drinking water on the go.


A water purifier shower head can be a great solution if you’re sensitive to chlorine.

More sophisticated models reduce even more than just chlorine for healthier skin, hair, and nails.


Water distillers heat water until it evaporates. The steam enters a cooling coil and is collected in a storage container as it condenses. Almost all impurities are left behind. This is why properly distilled water is the cleanest water possible. And the process works with almost any water source.


Similar to countertop water purifiers, faucet units easily connect to any standard faucet or tap. No need to make any permanent changes to your plumbing system. Required budget? Surprisingly small.

Reverse Osmosis Water Filter System

Last but not least, reverse osmosis systems. They come as countertop, under sink, or whole house units using multiple purification stages. At the heart of each system is a RO membrane which rejects up to 99% of all water impurities.

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I hope this list of the best water purifiers was helpful. Questions? Ask away!

And keep in mind: We’ll add new water purifier reviews occasionally. So come back for more!

About the Author Gene Fitzgerald

Gene Fitzgerald has been with BOS since the very beginning. She is head of content creation and has fully immersed herself into the home water treatment industry only to become an expert herself. Outside of BOS, Gene loves reading books on philosophy & social issues, making music, and hiking.
Learn more about Gene and the rest of the BOS Team.


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