kitchen faucet with running water

You've already decided that you want to have some kind of water filter for your home. Am I right?

But maybe you're not sure what kind you want or need. I know it can be a little overwhelming.

So I've put together this guide to help you understand what the different options are and how to decide which one is best for you.


You'll find explanations of all the common types of water filter systems available for home use and things you should consider in making your decision. I hope you'll find it helpful.

3 Steps to Determine Which Water Filter is Best

There are three basic steps to making the right decision about your water filter.

Step 1: Determine Your Water Quality

What do you want to filter out? Are there specific contaminants like lead or fluoride that you're concerned about? Or is it just that your water tastes or smells funny?

If you're not sure, there are a couple of things you can do.

One is to read your local water quality report if you are on a public water supply. You can look for your system at the EPA Consumer Confidence Reports (CCR) page.

If you're on a private well or if you're not 100% confident in the government report, you can have your water tested. 

Click here to find a state certified laboratory where you live.

You can also find home water testing kits online. They may not be as thorough as the state testing labs, but they're a good place to start. You'll want to be sure that whatever test you use checks for lead.

STEP 2: Determine the Capacity You Need

How many people live in your home? How many gallons of filtered water will you need each day?

Do you only want to filter water for drinking? Or will you use it for cooking, too? What about bathing and showering? 

STEP 3: Make the Decision

Take a close look at the features of the different types and brands of filters. Then decide which one will meet your needs in terms of contaminant reduction and capacity.

Points to Consider

You'll want to keep these three things in mind while you're evaluating the different types of filters:


One type of filter might be effective for removing certain contaminants, but not others. Among different filters there can be a difference in the percentage of reduction, too.

And then there are some filters that remove virtually every contaminant.

So be sure to pay attention to the degree of effectiveness for the contaminants that you're most concerned about.


Some water filters are connected to your plumbing. All you have to do is turn on the tap to get clean filtered water. This would include whole house filters and undercounter carbon block or reverse osmosis systems.

They're simple to use, but there's the installation to think about. You'll either have to install it yourself or hire a plumber to put it in.

Others take a little more effort on your part because you have to fill them manually with tap water. Pitcher filters, distillers, and gravity filters are examples of this type.

Of course, it's not hard to fill those by hand, but you have to stay on top of it or you'll run out of filtered water. Then you'll have to wait a little while to make more.

The advantage is that they're portable and you don't have to mess with the plumbing.

So think about whether you're willing to refill a filter system one or more times a day, or whether you'd rather have an installed system.


You can spend anywhere between $20 or so for a pitcher filter to thousands for a fancy installed multistage system.

That's just the initial cost. Then there's the cost of any ongoing maintenance like filter replacement.

Think about whether you can afford to maintain the system you choose.

POE versus POU

In the broadest sense, there are basically two categories of water filters:

Whole House/Point of Entry (POE)

In other words, with POE, the water encounters a filtration system first thing when it enters your house. This is going to filter all of your water - all sinks, washing machine, bathtub, exterior spigots, etc.

I don't cover whole house filters in this blog.

Point of Use (POU)

With POU, the filtration happens where the water is actually being used. Some types are connected to the plumbing at a single location, like under a kitchen sink. A reverse osmosis system is one example.

Others are countertop units that need to be filled by hand. Pitcher filters, faucet-mounted filters, gravity filters, and distillers are types of POU filters.

Water Filter Technologies

There are quite a few water filtration technologies to choose from. 

Each material and method has its own strengths and weaknesses and level of effectiveness. That's why it's important to know exactly what you're getting when you buy a water filter.

So, here's a list of the most common methods and a description of each. Some of them might be used as standalone filters, and some are combined with other technologies as part of a system.

Activated Carbon

Activated carbon can come from any kind of organic material that has a high carbon content. You'll often see carbon filters made from coconut shells, for example.

It's a porous material with a slight positive charge that attracts impurities and makes them adhere to the surface. This is called adsorption.

Not all carbon filters are equally effective, though. Some of them only get rid of chlorine and bad smells and taste. But others can remove a lot of different organic compounds like VOCs and radon.

Carbon does not work for inorganic compounds like fluoride, arsenic, heavy metals, and chromium-6.

There are two common types of carbon filters: carbon block and granular activated carbon (GAC).

Carbon block filters have a greater surface area, so they're generally more effective than GAC filters.

Because carbon filters collect contaminants, they eventually reach a saturation point and have to be replaced.


Ceramic filters have tiny holes that allow water through while blocking particles of dirt and certain contaminants. While they're effective for filtering out bacteria and protozoa, they're not able to block viruses or chemicals.

Sometimes ceramic filters are embedded with silver, which is a natural bactericide. That's to prevent bacteria and algae from growing on them.

As long as they don't get broken, ceramic filters can be used for years, so they're an economical choice.


Distillation works by boiling water and collecting the steam. As the water evaporates, the contaminants are left behind. When the vapor cools, it returns to liquid form. 

Biological contaminants like bacteria and viruses are killed by the boiling.

There are a few VOCs that have a lower boiling point than water, so they're not removed by distillation. Most home distillers have a carbon filter to take care of those contaminants. The result is pure H2O with nothing else in it.

Reverse Osmosis

In reverse osmosis (RO), water is forced through a semipermeable membrane. This membrane will block any particles that are bigger than the water molecules.

An RO membrane will block bacteria, viruses, protozoa, and many chemical contaminants like arsenic, fluoride, lead, and nitrate. But it won't work on chlorine, VOCs, or trihalomethanes.

That's why reverse osmosis systems always combine an RO membrane with one or more carbon filters. Together, they make a complete purification system.


Ultraviolet (UV) light is used to disinfect water by killing bacteria, viruses and protozoa.

Well, it doesn't actually kill them. What it does is attack their DNA so they can't reproduce. Almost the same thing.

UV purification is usually paired with reverse osmosis or some other form of filtration.

Most Common Types of Water Filter Systems

In this section, I'm going to tell you about the different ways that filter systems can be set up. You might find one filtration technology used in several types of systems. 

Faucet Mount Water Filter

Faucet-mounted filters are attached to the end of the faucet. You just take off the aerator and screw the filter on in its place. 

Pur PFM400H faucet water filter

There's usually some type of off/on switch so you can turn it on when you want filtered water and then turn it off for washing.

Most faucet-mounted devices use an activated carbon filter to improve the taste and smell of the water. Some models are able to remove other contaminants like lead.

Faucet Mount Filter Pros and Cons


  • Simple installation
  • Inexpensive
  • Can switch between filtered and unfiltered water


  • May slow down flow of water
  • Doesn't work with all faucets
  • Filters have to be changed often

Average price range: $15 - $50

For more information about choosing a faucet water filter, please see Faucet Mount Water Filters: Which One is Best?

Countertop Water Filter

A countertop system connects to the faucet, but the filter unit sits on the counter next to the sink.

Some models have an attached faucet, so you dispense the water right from the filter.

Propur countertop water filter

Others send the water back through the sink faucet, and you toggle the filtered water on and off using a switch.

Different models use different types of filtration. The simplest ones just use activated carbon, but there are others with multiple filters. You can even get countertop reverse osmosis filters!

So, of course, the types of contaminants removed can vary greatly from model to model depending on the type of filtration technology they use.

Countertop Water Filter Pros and Cons


  • Easy to install
  • Can switch between filtered and unfiltered water
  • Doesn't use up cabinet space under the sink
  • Longer filter life than faucet mount


  • Takes up counter space
  • Some models don't attach to faucet and require modification

Average price range: $30 - $300

Want more information about choosing the best countertop water filter? Please see Your Guide to the Best Countertop Water Filters.

Water Distiller

A water distiller looks a lot like a coffee maker. It sits on the counter, and it runs off of electricity. 

It has two containers - a boiling container and a collection bottle of some sort.

Megahome water distiller

To use it, you fill the boiler with tap water, put it in place in the unit, and push the start button. The machine does all the rest.

The process is slow. It can take between 3 and 6 hours to distill one gallon of water, depending on the model.

Home water distillers always have a small carbon filter to remove any VOCs that might be left in the water after distillation. It's possible that you don't even need that extra filter, depending on the quality of your tap water.

Some people don't like the fact that even good minerals are removed during distillation. This can be remedied by adding a pinch of salt or liquid minerals to the distilled water, if you like.

Water Distiller Pros and Cons


  • No installation
  • Easy to use
  • Portable


  • Takes up counter space
  • Very slow
  • Needs electricity
  • Gives off heat

Average price range: $100 - $800

For more information about choosing a water distiller, see my article, Best Home Water Distiller Options.

Learn more about the health benefits of distilled water here.

Pitcher Water Filter

Water filter pitchers are straightforward and simple. 

They have a reservoir on top that you fill with tap water. The water drips down through the filter and collects in the bottom part of the pitcher.

Clearly Filtered water filter pitcher

You can find pitcher filters in all kinds of styles and colors. Most of them hold about 2 quarts, but some are bigger than that.

There's a wide range when it comes to effectiveness, so you'll want to be sure to take a close look at the specs if you're thinking about getting one.

All of them remove chlorine and bad tastes and smells at a minimum. But a few are more advanced and can remove things like lead, fluoride, VOCs, and pesticides.

You'll also want to pay attention to the price of the replacement filters and the filter life. Sometimes replacing the filters almost costs the same as buying a whole new pitcher.

Or you might find that it ends up costing more than a different, more effective type of filter.

Pitcher Water Filter Pros and Cons


  • Different styles and sizes available
  • Inexpensive
  • Portable
  • No installation


  • Have to refill frequently
  • Most are hard to pour without spilling
  • Filter replacement can get expensive

Average price range: $30 - $80

Under Counter Carbon Block Water Filter

These filters are connected to the water supply and are installed under the sink. They have their own faucet mounted next to the regular sink faucet.

When you turn it on, water flows through the activated carbon block filter and out the faucet.

AO Smith Single Stage Carbon Water Filter at Amazon

Carbon block filters mostly just remove chlorine and make the water taste and smell good. Some brands are more effective than others and work on a wider range of contaminants.

Under Counter Carbon Block Water Filter Pros and Cons


  • Doesn't take up much space under the sink and none on counter
  • Long filter life
  • Affordable


  • Installation required; may need a plumber
  • Limited effectiveness
  • Filter replacement can be a hassle

Average price range: $50 - $500 (plus possible plumber fee)

See my review of the best under sink water filters for more details about this type of filter.

Under Counter Multi-Stage Water Filter

Multi-stage filters are hooked up to your plumbing, and they have their own dedicated faucet. That means you might need to hire a plumber if you're not comfortable trying to do it yourself.

They combine several different filtration technologies. That's why they're called "multi-stage".

APEC RO-90 reverse osmosis system

Most of them include a reverse osmosis membrane plus two or more activated carbon filters.

Other options you might find are a UV filter for disinfection or a filter that adds minerals to the water. Sometimes you can buy a basic system and then add on more stages later if you want.

The contaminants that are removed vary from product to product, depending on the types and quality of filters they use. So you really need to look at each model's specs to see how effective it is.

I will tell you, though, that reverse osmosis systems are generally good at removing most kinds of contaminants.

Under Counter Multi-Stage Water Filter Pros and Cons


  • Constant supply of drinking and cooking water
  • Can customize
  • Doesn't take up counter space
  • Long filter life


  • Installation required; may need to hire a plumber
  • Takes up space under sink
  • Expensive replacement filters

Average price range: $200 - $500 (plus possible plumber fee)

If you'd like more information about reverse osmosis systems, please see my article Best Reverse Osmosis Systems | Reviews & Ratings.

Testing and Certification

Sometimes you'll see water filters that are "NSF certified" or "tested to NSF standards".

What does this mean, and does it matter?

First, what NSF is:

NSF International is an accredited, independent third-party certification body that tests and certifies products to verify they meet (certain) public health and safety standards. Products that meet these standards bear the NSF mark. (link)

There is no requirement that water filters be NSF tested or certified. It is not a government agency and doesn't regulate anything. NSF testing and certification are strictly voluntary.

Most reputable water filter manufacturers do have their products tested by independent laboratories, and they're happy to share the test results with the public. 

It's my opinion that examining independent lab test results is more important than seeing an NSF emblem on a product. NSF certification means that the product has passed the minimum standards set by NSF.

Some products far exceed that standard even though they haven't been tested by NSF itself.

Also, it's very expensive for companies to have their products NSF certified, so they may choose not to pursue certification.

When you see that a product is "tested to NSF Standards", that means that it has been tested using the same criteria. But, you don't know if it met or exceeded the standards, or if it even fell short. The only way to know this is to check the independent lab test results.

So, while NSF certification can be useful in determining the quality of a water filtration product, it's not the ultimate proof that the product is worthy of consideration.

To learn more about NSF certification for water filters, visit the NSF website here.


Congratulations if you made it all the way to here! That was a lot of information to take in!

Let me give you a quick summary of how to pick the best water filter:

  • First, determine which contaminants you want to eliminate from your water.
  • Next, estimate how much filtered water you'll need every day.
  • Then, decide which types of filters will meet your needs.
  • Last, take a look at your budget and buy the best one that you can afford.

If you still have questions, feel free to leave a comment and ask away. I'll do my best to answer as soon as possible.

Last Updated on April 5, 2022

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  1. Hi Marge,
    Thank you for the detailed reviews. My question is – would there be any issues with having both POE and POU systems installed? I know that we need to filter lead from our drinking water, plus it just doesn’t taste very good, but I would also love to clean up our other household water, remove chlorine, etc.
    I guess the question is would a POE system filter out good minerals that we would want to add back with an RO system?

    1. Hi, Michelle! You could definitely do both. A POE filter may or may not take out the minerals, depending on the type of system it is. If it’s a carbon filter, it will leave the minerals in. You’ll just have to do your research on whatever brand it is you’re considering.

  2. I just realized that I have another question. Thanks for answering my last one. The question is: do these stainless steel gravity water filters leak if you put more in the top than will fit in the bottom; another way of putting it is, do you have to check the level in the bottom before adding water to the top?

    1. Hi again, Jack! Yes, if you put too much in, the bottom chamber can overflow. I’ve done it myself.

  3. Hello, and thanks for your very informative site. I am using it as a guide to help me choose a water filtering system, and I appreciate your careful examinations of these products. Best regards…

  4. I am looking for the water type pitcher for the refrigerator so I won’t have to refill it so often. Any suggestions. Your article seems the best advice. Need information on filling and carrying also. Thanks!

  5. Hi,
    My baby, husband and I just moved to a very rural community in california. We have well water and it is unsafe for drinking and cooking. The water contains pesticides, herbicides, bacteria, and metals. I’d like to install a filter for our kitchen sink (I’m open to either under the counter or counter top, depending on effectiveness). Ideally i would like to install something that also filters out minerals, but can also use a secondary filter. My main priority is filtering out anything toxic for my baby. Do you recommend a specific product?

    1. Hi, Veronica! If you want to filter out minerals, you’ll have to go with a reverse osmosis system. The other kinds of filters don’t remove minerals. Water distillers remove everything, including minerals, but you can’t attach them to the plumbing, and they’re slow.

  6. I like how you mentioned to find specific contaminants that you’re worried about like lead or fluoride. My wife and I are thinking about getting a water filtration system for our home because we don’t like how hard the water is when trying to wash clothes or take showers. It seems like a good idea to identify what things we want a filtration system to do if we get one.

  7. Hello Marge, Both myself and my son have been tested and found to have very high levels of lead in our systems. We live in Paris and I think it is not from our apartment itself but from old pipes in the city, and particularly in my neighborhood which is quite run down. I’d like to put a filter where the water comes into the whole apartment (POE), which is under the bath. I don’t mind getting a plumber in to install it, but there is not a lot of room to work with. There is not room for extra tanks. What is the smallest, most effective? Recently I got a filter system for the kitchen tap but don’t like that lead is still getting into our skin through the bath water, laundry etc. Tests this week show that lead remains high and recent in our systems. Thank you for sharing your thoughts and recommendations.

    1. Hi Susan! POE filters are not my specialty. Plus, you don’t live in the US, so I don’t know what’s available for you. I’d recommend that you contact a local water treatment company – something similar to Culligan here in the US.

  8. Hi Marge these are the three contenders:

    CWR Crown Triple AIO Undercounter Ultra Water Filter with Metalgon



    Thanks so much for your hepl!

    1. Hi again, Carlo! I did a quick comparison of those 3 systems, focusing mainly on contaminant reduction and filter life.

      Here are the links for the 3 products, in case anyone else reading is interested in checking them out:

      The info on the CWR page is a little confusing. For example, in one place it says chlorine is reduced 90%, and then further down it says 99%. Which is it? I don’t know.

      But, overall, it seems to me that they are all pretty much equal in what they reduce, with the exception of the Propur. It doesn’t have microbiologicals listed on the lab test results, so apparently it does not reduce them. I could’ve sworn I saw it there before, so I’m going to double check with Propur on that. If you’re on city water or a clean well, then it shouldn’t really matter. BTW, Propur is the only one of the three that actually publishes their third party lab test results.

      The filter life for both Propur and Aquacera is one year. The CWR, however, is a little more complicated. If you have 1-3 people in the household, one filter is good for 6 months, but the other two is good for 9- 12 months. So it would take a little more effort to keep track of when the filters need to be replaced.

      As you said, the CWR is quite expensive – about twice as much as the other two. The replacement filters are also more expensive.

      I’m not so sure that the high price tag on the CWR is worth it. I’d personally go with one of the other two.

      Let me know what you decide to do. And I’d love to hear what you think after you’ve had a chance to use it.

    1. Hi, Ginky! You should probably look into getting a whole house filter – a POE (Point of Entry) filter. If I needed to install one at my house, I’d look for a local contractor to do it.

  9. I had my water tested and the only issue but big issue is arsenic. Maximum level is .01 and ours is .012. Ugh! I am afraid it has been like that for a long time and I didn’t do anything about it. Looks like the RO system would be the best but not sure if should just do at POU or go for the POE also. Any suggestions? Then I need to find a good brand to purchase. There are a few places around that sell them.

    1. Hi, Sue! I’m sorry to hear that you’ve got a problem with arsenic in your water. I’m guessing you’re on a well?

      A 0.012 reading doesn’t sound like much, but it really is too high. The closer you can get to 0, the better, because arsenic is really bad for you.

      Fortunately, arsenic is not easily absorbed by the skin. All you really need to worry about is drinking it and cooking with it. So, a POU (Point of Use) filter might be all you need. But, you’d probably need to install filters in your bathroom(s), too, since most people swallow some water while brushing their teeth.

      Reverse osmosis will remove arsenic, but there are other under-the-sink filters that also can remove arsenic.

      Propur makes one that reduces arsenic 99.9% and Clearly Filtered has one that reduces arsenic 94.3%.

      The Propur one is included in my review of the best under sink water filters or you can see it at the Propur website here.

      I’m actually working on a review of the Clearly Filtered under sink filter now. I’ve got a model that I’ll be installing over the weekend and will be posting the review in a few days. You can see it at the Clearly Filtered website here.

      Your other options would be a distiller or a gravity filter (Propur, Berkey and Alexapure are the best at reducing arsenic). But those aren’t as convenient as an under sink filter. You could really only use those for drinking.

      I hope this helps.

  10. The quality of water in my home is off normal limits and I have been using an RO filter which is expensive. Nice presentation of the types and the process to select a water filter.

  11. Hi Marge,

    I’m very glad to have found your website.

    What is your advice for apartments when a whole-house filter, or making a hole in the counter, are not options? Additionally is there any way to get hot water through faucet-mounted filters?

    Thanks so much,

    1. Hi, Hanna! You could use some sort of countertop filter – either one that hooks up to the faucet or one that you fill manually, like a gravity filter or pitcher filter.

      You can run hot water through a faucet mount filter, but it’s not recommended. Most faucet mount filters I’m aware of are designed only for cold water use. Hot water can make them clog up and wear out quickly. See my review of faucet mount filters for more information.

  12. I am looking forward to buying a new filter for my home and I think all this information you described will help me a lot while buying this. Thanks for sharing this amazing post.

  13. I’m just getting started, and you have so many blogs, thanks! Thought I liked the pitcher reviews, what containers would I use to always have minimum of 3 gallons/day. I’m thinking that pushes me to a POE, but, would reverse osmosis be better, haven’t seen the pricing, but would I need to add minerals? I drink a lot of water, tea, coffee, and cook at home. Drawbacks? Thanks

    1. Hi, Laura! To answer your question about reverse osmosis and minerals – ro does filter out all minerals, so if you want minerals in your water, you’ll need to add them back in. Some ro systems, like the iSpring RCC7AK have a stage that adds minerals back to the water after it’s gone through the ro membrane. We get most of our minerals from our food anyway, so it’s probably not all that important.

      POE systems filter all the water in your house, so that might be overkill. Plus it’s quite expensive. If you use a lot of water in the kitchen, the most convenient option is an under sink filter. I’m not sure that I can offer any more advice than what I’ve already written in the article and other articles that it links to. I hope you find the perfect water filter for you!

  14. I like your advice to consider how the water filter will be used, such as if it’s connected to your plumbing and will work when you turn on the tap. This could help you find one that is affordable and easy for you to use. When choosing, it might help to consider your habits as well as the habits of other people in your home so that you can ensure everyone can enjoy the benefits of the water filter.

  15. It’s great to know that countertop water filters can switch between filtered and unfiltered water. That would be a big benefit because then you could decide what you’d rather have for cooking and drinking purposes! We want to have some sort of water filter so that our water is safer to drink, so I want to look into countertop filters more and see if we can get one soon.

  16. Hey Marge! Great blog topic. Some other things to consider is what kind of water are you using? City or well water? Some well water requires extra levels of filtration. I agree the best thing to do before choosing a filtration system is to test your water so you know what you’re dealing with.

  17. One important question is, “what do you want to filter out?” Personally, I prefer to filter Chlorine. Imagine how much Chlorine we absorb in our body from taking a shower and drinking water. It absorbs quickly in seconds, so we should choose the best water system that filters out the most harmful contaminants.

  18. Hi Marge, I’d like to thank you for your explanation in identifying the water filter best factors as well as its types. I had no idea that there is a way to test it at home. However, if you were to ask me, I prefer a professional to do the testing for me. Nonetheless, I appreciate all the information you’ve shared here. More power!

  19. It really can surprise people to realize just how much thought has to go into choosing a water filtration system for their home. In fact, the article brings up the importance of a pretty good point with ease of use. After all, you want to make sure that the people in your home can actually use the filter that you spent money on to install.

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