Types of Water Filters: What Do I Need?

What are the different types of water filters? Our guide makes the process of choosing a water filter more straightforward. It can help in making a big decision, a little bit easier.


what-filter-do-i-need - types of water filtersChoosing a water filter can be a confusing experience, because of all the different types of water filters available. There are many types of water filters for home use, and all water filter types offer something different. Some are easy to look after and to install, while some require a bit more maintenance and care.

We created this page to make the process of choosing a water filter a bit easier. Your choice of the proper type of water filters will depend on your specific needs. Without reliable advice from a knowledgeable source, the question “what water filter do I need?” can seem insurmountable. It’s easy to get overwhelmed by all the options available, but with our guide, we hope the choice is much more straightforward.

We will help you choose from the different types of water filters used at home, by asking some simple questions. We can then point you in the direction of some more information on the kind of water filter that best fits your home, so you can improve your household drinking water quality by installing your own water purification filtration system, and stop relying on expensive bottled water once and for all.

So, What Types of Water Filters Are There?

What are the methods used to purify water? How do water filters work?

Water purification methods include physical processes such as filtration, sedimentation, and distillation; biological processes such as slow sand filters or biologically active carbon; chemical processes such as flocculation and chlorination and the use of electromagnetic radiation such as ultraviolet light. All of these water treatment methods are used by various water filter types and filtration systems to produce pure water.

Activated Carbon Filters

Also known as carbon or pre-carbon filters, these devices remove large particles such as sediment and silt from your drinking water supply. They work by binding to or absorbing them from your tap water. One of the greatest benefits of using activated carbon filters is that your tap water will have a reduced odor and better taste. The presence of chlorine and other contaminants is significantly lowered.

Reverse Osmosis

This type of filter is popular since it is able to remove hazardous contaminants from your water and make it odor-free. You may be wondering how the best reverse osmosis water filters work. In regular home units, municipal water is pushed through a carbon pre-filter first. This removes organic contaminants and chlorine. The reverse osmosis process is secondary. It allows water to pass but rejects dissolved liquids include impurities such as arsenic and lead. Purified water is stored away in a small tank until you need it. When you open the mounted faucet, air pressure forces the purified water into another filter, giving it a final polish from there to the ledge faucet. While this is an oversimplification of the process, it is a good way to understand how a three-stage RO unit works. Additional stages such as sediment and carbon filters can be included if you desire it.

Alkaline and Water Ionizers

Alkaline and water ionizers used a process called electrolysis to filter your drinking water. What does this mean? When water passes over electrically charged plates, it divides into two streams. One water stream is alkaline and the other is acidic. As a result of alkaline and water ionization treatment, you not only get water with a low acidity count but you get softer water that is better for your skin and hair as well.

UV and Infrared Water Filters

Ultraviolet light (UV) filters are one of the newest technologies in the water filter industry. UV filters destroy bacteria that pose a risk to your health. In addition, it is also environmentally friendly, as it does not use any chemicals or heat. Similar to alkaline filters, infrared filters are used to soften your water. They use a combination of heat and light to negatively charge the water.

How Does Activated Charcoal Filter Water?

Activated charcoal is charcoal (carbon) that has been treated with oxygen to open up millions of tiny pores between the carbon atoms. These “activated” charcoals are so porous that they are extremely efficient at absorbing polluting substances from gases or liquids. Activated carbon is the key element in many water purification systems, with activated carbon filters providing pure water, improving the taste and smell of tap water in a huge proportion of the water supply. Even the producers of commercial-grade distilled water and bottled spring water use such filtration as part of their process.

What Are the Different Types of Water Filters?

Activated Carbon Filters (also known as carbon filters, sediment filters, or pre-filters) remove larger particles like sediment and silt (and larger bacteria) from your filtered water.
Reverse Osmosis Filters use a series of graduated filters and a semi-permeable membrane to screen water under pressure and remove even the smallest particles (like heavy metals) from the water supply.
Alkaline/Water Ionizers use electrolysis, passing water over electrically charged plates to separate it into two filtered water streams, one alkaline and one acidic.
UV Filters use ultraviolet radiation to treat water. UV has the ability to destroy various forms of dangerous bacteria to clean water.
Infrared Filters are similar to alkaline filters. Infrared uses heat and light to negatively charge hard water, giving it a softer feel.

Which Water Filter Removes the Most Contaminants?

Reverse Osmosis Filters usually remove the most contaminants, minerals, and particles. However, RO water purifiers can be expensive to install and maintain, and might not be the best water treatment solution for your particular needs. Flow rate is also a concern. RO filters seldom have as rapid a water flow as other, less comprehensive filtration systems for water.

The Best Types of Water Filters

So what type of water filter is the best for you? Well, it depends. What is in the water supply that you want to filter out? Do you want to get rid of the weird taste and smell in your tap water? Or have you conducted a water test and found hazardous contaminants in it. We began our search by seeking out the top-rated carbon filters and mounted filters. You want an effective device that has low upfront costs, is effective, and requires little to no installation.

Remember, carbon isn’t the only way to filter your drinking water. There is also reverse osmosis and whole-house systems that can be built into your plumbing. With this said, for those seeking an easier and more economical alternative, water pitcher filters and faucet filters are a great purchase. Since they are certified by a third party, the water you get from these filters is guaranteed to be healthy. To make the cut, your filter should be certified by NSF-42 or NSF-53. These certifications require that the water filter improves the taste and odor of particles in the water and reduces hazardous metals and chemicals, respectively.

You should also take a look at each of the certified brands and their flagship filter. More often than not, these models have updated technology. For example, Brita offers a water filter with a wifi beacon that automatically orders replacement filters as needed. Below, we have included a list of factors to consider as you search for the right types of water filters for you.

Taste and Odor

Getting good tasting drinking water means you have to strike a balance. Obviously, you do not want to drink hard water. On the other hand, water stripped of potassium and sodium does not necessarily make it taste better. Most people tend to prefer tasteless water and add their own mineral supplements for flavor. All in all, total dissolved solids (TDS) does not indicate any health concerns. It deals more with the taste and odor of water. With this said, the Environmental Protection Agency (EPA) advises against drinking water with a TDS reading higher than 500 mg/L.

When it comes to water pitchers, we searched for durable parts and leak-free lids. We also looked for durability and a leak-free design when it came to choosing the best faucet filters. Sink filters can last somewhere between 100 to 200 gallons of water whereas most pitcher filters last for about forty gallons before they need to be replaced. Even these numbers need further consideration. David Beeman, the developer of the Soma Water filter said: “I always downrate a filter by a minimum of 50% of what it claims.”

By now, we all know how harmful bottled water is to the planet and that they contain chemicals hazardous to our health. So when the answer comes down to is tap water better for the environment and safe to drink, the answer is yes. As we have mentioned before, plastic is not biodegradable. In fact, it can take up to 1,000 years for a plastic bottle to decompose. The U.S. alone uses approximately 1.5 million barrels of oil per year just to produce plastic water bottles. This does not even take into account how much oil is needed to transport these bottles worldwide. Most water bottles are consumed outside of the home and are simply thrown away instead of properly recycled (nearly 80% of plastic bottles are not recycled).

Even so, bottled water is still the fastest-growing beverage industry. Americans drink an average of 167 bottles of water per year. As ironic as it may be, Americans also have reliable tap water to drink – nearly nationwide. So why do we continue to pay for someone to bottle water (sometimes even tap water) when we could filter it at home. Tap water not only tastes like bottled water but it contains far less harmful contaminants. In fact, tap water is safer than bottled water for children to drink. After all, it contains fluoride to strengthen teeth. For those of you who are concerned about trace contaminants, invest in a good water filter.

Here’s another proof using water filters. You will find yourself saving money in the long run. Think about it. If the average American really does use 167 bottles of water per year and the average cost of one bottle of water is $1, then you should have around $167 extra dollars in your pocket per year. Who doesn’t want that?

Types of Water Filters: What Do I Need?

There are two ways that you can base your decision. You can choose the best water filtration method for your home according to:

A) The type of water filtration that will fit your lifestyle & budget.

If for example, you need to filter ALL of the household water, then you need a whole house water filter. However whole-house filters tend to be expensive.

If money is tight, then a faucet filter would be a good choice. Faucet-mounted filters can improve your water quality more economically.


B) The specific contaminants that you are worried about.

If you are particularly worried about lead contamination (for example), then you can choose a filter that specializes in this problem.


We recommend always going with option B unless circumstances force you otherwise.

Ok, let’s deal with each of these methods of choosing from the different kinds of water filters in a bit more detail.


Method A – Choosing based on lifestyle & budget

There are a few important questions that need to be answered here. Rather than ramble on, we’ve put together an infographic below that should help you arrive at a decision. You can click on the links in the image to learn more about each method of filtration or read on for a brief introduction to each type of water filter.


Designed by Freepik


best-whole-house-water-filter-reviews-2 - types of water filtersWhole House Water Filter

Installation: Medium to Hard

Price: $ to $$$$$

Effectiveness: Medium to Very

A whole house filtration system is installed where the main water line enters the home. Therefore, it filters ALL of the household water (drinking and bathing). However, this means installation is a bit more complicated, and basic DIY skills are needed.

These systems can be very cheap for a simple 1-stage of filtration, and the price increases with each extra stage of water filtration (usually up to 3-filtration stages).

They can filter particles down to 0.35 microns in size, but more commonly 1-5 microns. This is a very good level of water filtration that is only beaten by reverse osmosis.

Read our guide to whole house water filters to learn all about them. We have reviews of the top systems, an installation guide, and a buyer’s guide.


types of water filtersReverse Osmosis Water Filter

Installation: Medium

Price: $$ to $$$$

Effectiveness: Extremely

A reverse osmosis system offers the most effective form of home water filtration available. It is usually installed under the kitchen sink and will filter the water at the kitchen faucet. Installation is not difficult and usually takes a couple of hours.

These units offer incredible water filtration of around 0.0001 microns. That means your drinking water is as pure as possible. This is achieved using the multiple filtration stages (usually 5 or 6), which include the reverse osmosis membrane.

Read our guide to reverse osmosis filters to find out more.


best-faucet-water-filter-reviews-2017-new - types of water filtersFaucet Water Filter

Installation: Easy

Price: $

Effectiveness: Medium

A faucet filter attaches directly onto your kitchen faucet. Installation usually requires no tools, and replacing a filter is simple.

They are not as effective as reverse osmosis systems, but they are cheap in comparison. The filters are also very well priced.

Read our guide to faucet filters to learn more.


countertop-water-filter-review-compilation-smaller - types of water filtersCountertop Water Filter

Installation: Easy

Price: $ to $$

Effectiveness: Medium to Good

These attach to your faucet head. No tools are required for the installation, which will just take a few minutes. These can offer more thorough filtration than the faucet and pitcher filters.

Some models have multiple filter stages, and pH balancing to make the water more alkaline. They offer a pretty good balance of value, effectiveness, and ease of use.

Read our guide to countertop systems to get all the details.


best-water-water-filter-pitcher-reviews-of-the-year - types of water filtersWater Filter Pitcher

Installation: None

Price: $

Effectiveness: Medium

These are the ultimate in convenience as there is no installation required. Pitcher filters are probably the cheapest method of water filtration (though faucet systems can be cheap too). The more advanced models make alkaline mineral water that tastes good.

Check out our guide to pitcher filters for more information.


Method B – Choosing based on the water contaminants

If you know exactly what is hiding in your water, then choosing a water filter that actively targets these pollutants is a great idea.

If you’re not sure what contaminants are in your water, then you should check out our guide to water testing. We highly recommend testing your water before choosing a water filter.

The most common water contaminants that we get asked about are:

  • Lead
  • Chlorine
  • Fluoride

Luckily, there are various types of water filters that target exactly these things. We’ve put together some resources that recommend the best filters to deal with these particular contaminants. We cover a range of filtration methods that should suit every home, budget, and lifestyle. Plus we also delve into the backgrounds of these pollutants to see where they come from, and how they happen to be present in our water. Click on the links below to find out more.

A guide to lead removal

A guide to chlorine removal

A guide to fluoride removal


We hope that you’ve found our guide useful. If you still have any questions then please get in contact with us. We promise to reply promptly.

You can also follow us on Facebook to stay up to date with all the latest news.

What are the 5 stages of water treatment?

When talking about a water treatment plant, there are indeed five stages through which the water must go to become ready for consumption. Let’s see what these stages are and what they do in the entire treatment process.

Chemical Coagulation

The first step in the water treatment process is to add chlorine dioxide, which breaks down naturally occurring organic matter. Chlorine dioxide removes bacteria, algae, and other organisms that form in water, but being an oxidant means that it needs coagulants to stick to the water and do its job properly. Aluminum sulfate and polymer are added as coagulants and bonding agents. After they do their job, the coagulants are later removed in the water treatment process.


The next process causes the coagulated particles to form floc. What the process does is basically to combine the flocculated particles to sediment. Water gets stirred to pass through the flocculated surface and leave any larger pollutants (like sediment) at the bottom, making it easier for the next two processes to remove this type of inorganic pollutants.


The main purpose of sedimentation is to reduce the particulate load on filters. What sedimentation does is remove suspended solids that are heavier than the water. Sedimentation is accomplished by decreasing the velocity of the water being treated below the point where it can transport settleable suspended material. The suspended particles are then removed by gravitational forces. Now that all the solids in the water have been removed, it’s time for the next step.


The disinfection process eliminates or deactivates most organic materials, including microorganisms like bacteria, pathogens, parasites, viruses, mold, etc.; it’s simple, as the process merely involves chlorine, just as you can add as well to your water supply with packages bought from a supermarket.


Finally, water passes through a screening material such as activated carbon, coal, sand, or other sediment-like multi-media filter bed. The water enters on top of the filter media and passes down through the filter beds by gravity. The different materials work like a giant strainer and trap remaining particulates. After this, the water is ready to flow towards all of the municipality’s residents.

Hi I'm Jamie, teacher and owner/chief contributor at waterfilteranswers.com. We strive to bring you the most informative water filter reviews in the most intuitive and user friendly way. Besides offering advice on the water filter to suit your needs, we also post topical articles on water pollution and the environment. Stay connected and follow us on, Facebook, Twitter, Google+ and more!

  1. What kind of whole house system would you recommend for treating well water that has elevated levels of arsenic and uranium?

  2. Hi Mike,

    Activated alumina is one of the best materials for removing arsenic from water, so I would recommend the APEX MR-3020 that we discuss in this post. Activated alumina will also reduce levels of uranium.

    Other very good well water systems are the 3-stage Home Master (HMF3SDGFEC) and 3-stage iSpring (WGB32B-PB) models. They also offer the chance to customize your filter configuration, as they use the common 4.5″ x 20″ filter sizes. This means you could easily integrate activated alumina filters into your set-up.

    Hope that helps,


  3. What is the best showerhead filter? Thanks

  4. We actually have a post dedicated to this subject. You can see it here.

  5. I need a really good water softener filter etc.. Whatever

  6. Advise please what kind of water filter I need for an Ecosmart 11 Tankless water heater. Thank You, Betty Martin (Missbetty2863@gmail.com)

  7. Which whole house filter or system will remove the sulfur smell from both hot and cold water (well water)?

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