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7 Types of Water Filters: Explained & Compared

Updated
If you’re feeling worried about water contaminants, let’s talk about water filters — all 7 types.

We are lucky that so many of us now have access to clean water at the turn of a tap, but just how clean is our drinking water? Contaminants such as bacteria, lead, and other harmful materials can have a negative impact on your health.

One of the most reliable ways to ensure your water is safe is by installing a water filter. However, with so many different filter types available, you might struggle to find the ideal filter for your plumbing and water supply.

In this article, we will explain the most effective filtration methods. We will then look at how those filtration methods are incorporated into some of the most popular filter types available today.

Key Takeaways

  • Water filters remove contaminants and improve the taste and odor of water.
  • Popular filtration methods include activated alumina, ceramic filters, and reverse osmosis.
  • Consider your water source, filter purpose, and home setup when choosing a filter.
  • Regular maintenance is essential for the effectiveness and safety of water filters.


Popular Methods of Water Filtration

Before we look at the main types of water filters, we will examine some of the most effective filtration methods. Each method has pros and cons, so it is important to consider the quality and type of your local water supply when deciding which one is best for you.

1. Activated Alumina

Activated alumina is commonly used to remove fluoride, arsenic, and thallium from drinking water. Fluoride isn’t a major issue in North America but this is still a popular filtration method and is used in the United States’ biggest fluoride removal plant.

It is a ceramic emulsion made of aluminum oxide. This is the same mineral composition found in rubies and sapphires but without coloring impurities.

There have been concerns that activated alumina will add aluminum to the water that is being treated. However, a study found that only trace amounts leaked into the water (1).

Pros

  • Effectively removes fluoride
  • Relatively inexpensive

Cons

  • Can leak trace amounts of aluminum

2. Ceramic Filter

Ceramic water filtration is a traditional method that has been adopted globally. It consists of a flowerpot-shaped filter that can hold up to 2.6 gallons of water. The filter is placed inside a ceramic or plastic receptacle, which is then filled with water.

The water flows through the ceramic filter, or filters, and enters the storage receptacle. At the bottom, there is a spigot that provides easy access to filtered water. Ceramic filters are effective at removing bacteria and large protozoans, but they aren’t as effective at removing viruses.

Keep In Mind

The quality of the ceramic material is critical. Studies have shown an increase in bacterial contamination due to poor-quality ceramic filters (2).

Pros

  • Natural method
  • Filters bacteria and protozoans effectively

Cons

  • Less effective at removing viruses

3. Water Distillation

This is one of the oldest and most effective methods of water filtration. There are three types:

  • Household
  • Plumbing distillers
  • Commercial distillers

This method purifies the water by using heat to vaporize it. As the water evaporates, it is separated from the contaminants (3).

Water distillation can filter out several contaminants such as:

  • Arsenic
  • Benzene
  • Fluoride
  • Lead
  • Biological contaminants

Pros

  • Highly effective
  • Improves the smell and taste of the water

Cons

  • Slow process

4. Reverse Osmosis

As the name suggests, reverse osmosis systems reverse the flow of water. The water passes from a concentrated solution to a diluted one through a semipermeable membrane (4).

Reverse osmosis systems can remove several contaminants, viruses, and bacteria, including:

  • Protozoa
  • Salmonella
  • Hepatitis A
  • Rotavirus
  • Lead

Pros

  • Highly effective at removing all kinds of contaminants
  • Doesn’t need electricity to function

Cons

  • Requires high water pressure to work effectively
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5. Ultraviolet Water Purifying System

A UV water purifier disinfects water by passing it through a glass, plastic, or stainless steel chamber. The harmful micro-organisms are exposed to intense UV light produced by a UV lamp and destroyed.

The lamp heats to approximately 104 degrees Fahrenheit, and a screen protects the bulb to prevent it from cooling (5).

Pros

  • Kills bacteria, parasites, and viruses

Cons

  • Doesn’t remove contaminants such as minerals or lead

6. Activated Carbon

Activated carbon filtration uses a layer of activated carbon to absorb impurities and contaminants and extract them from the water.

The carbon particles provide a large surface area of pores to filter out harmful impurities.

They are effective at removing material such as:

  • Chlorine
  • Volatile organic compounds
  • Odors and tastes

Pros

  • Removes contaminants, bad odors, and tastes
  • Doesn’t require electricity

Cons

  • Can’t remove minerals or salts

7. Granulated Carbon

These filters use tiny granules of carbon to purify your water. Granulated carbon has a smaller surface area than activated carbon, making it less effective.

They will remove the same contaminants as their larger counterparts. Water pressure has a significant influence on its effectiveness.

Pros

  • Inexpensive.

Cons

  • Less effective.

8. Ion Exchange

Ion exchange filters use a resin to replace harmful ions with less harmful ones. This method is often used in water softeners because it can replace magnesium and calcium with sodium.

These filters require regular recharging to work for an extended period. This is accomplished by adding harmless ions for replacement.

Pros

Cons

  • Requires regular maintenance

Types of Water Filters

Now that you know more about the different filtration methods, it’s time to explore the most popular types of water filtration systems currently on the market.

1. Water Pitcher Filters

Water pitcher filters are a widespread and affordable solution. They look similar to a standard pitcher but have two compartments inside.

The filter part is mostly filled with granular activated carbon and resins. These trap contaminants as the water flows through. They are effective at reducing pollutants such as lead (6).

Pros

  • Free-standing
  • Improves the taste and odor of water

Cons

  • Short lifespan and needs to be replaced regularly

2. Faucet Water Filters

Faucet water filters attach to standard faucets. They can be switched on or off when you need filtered or unfiltered water. These systems are inexpensive and easy to install, making them one of the most popular types of water purification systems (7).

Pros

  • Attaches easily to most modern faucets
  • Filters water as it leaves the faucet

Cons

  • Slows the water flow

3. Whole House Water Filters

Whole house water filters filter all the water that enters your home. You will receive cleaner water for your showers, appliances, and to drink. They are particularly effective in areas with hard water as mineral-rich water can also affect appliances and stain your laundry.

Pros

  • Treats all water in your home
  • Removes volatile organic compounds

Cons

  • Requires professional maintenance

4. Under Sink Water Filters

Unsurprisingly, these are installed under your sink. They filter the water as it flows through a pipe and out of a specific faucet.

Under sink water filters tend to occupy quite a lot of space. They are also more expensive than some other types.

Pros

  • Filters water quickly
  • Won’t occupy countertop space

Cons

  • Sometimes require plumbing modifications

5. Countertop Water Filters

Countertop filters, also called on-counter water filters, are compact devices that you connect to your faucet. They clean the water when you open the tap, and some are even included with a spout. Despite being small, these filters can still occupy a significant area on your countertop.

Pros

  • Can switch easily between filtered and unfiltered water
  • Might have a dedicated spout

Cons

  • Requires installation

6. Refrigerator Water Filters

Refrigerator water filters are installed in a refrigerator, and the water usually flows from an outlet on the door. Most refrigerator filters use a combination of carbon and sediment filtration to remove unpleasant odors and tastes.

The filtration process features a carbon block that is wrapped in a material such as polypropylene. Contaminants will stick to the carbon block but won’t be absorbed.

Pros

  • Removes bad odors and tastes
  • Eliminates contaminants

Cons

7. Portable Water Filters

Portable water filters are a must-have for campers and hikers. They enable you to filter any water while on the move and effectively remove micro-organisms.

Pros

  • Small size
  • Removes micro-organisms

Cons

  • Only filters a limited amount at a time

What Type of Water Filter Is Best?

Which type of water filter is best for you depends on a few factors. Just because a particular filter works for someone else, it doesn’t necessarily mean it will suit your location and plumbing.

Here are a few things to consider before choosing:

1. Water Source

Consider where your water comes from, such as a municipal supply, private well, or cistern.

Water from a private well should be tested by a certified laboratory annually. These tests will look for things such as total coliform bacteria and pH levels.

If you get your water from a public supply, you should receive an annual water quality report. This will include information about specific contaminant levels. Having a fuller understanding of your water source will help you identify what you need to filter out.

2. Why Do You Want a Filter?

Knowing why you want a water filter will help you choose the most suitable type. Common reasons include:

  • Bad taste: A bad taste can be due to disinfectants, minerals, or sulfur. Many filters, such as refrigerator and pitcher filters, are designed to improve the taste and odor of water. They will also protect against harmful contaminants.
  • Lead: Lead is a serious problem across the United States. It finds its way into the water as it flows through pipes. Many filters, particularly reverse osmosis models, are very effective at removing lead.
  • Hard water: Water that contains large amounts of minerals is referred to as “hard water”. Hard water can leave a residue, block taps, and prevent soap from lathering. You can use water softeners to combat this, although these won’t treat bacteria. Instead, opt for a filter that removes minerals (8).

3. How Will It Fit Your Home?

Consider the space you have available and what the filtered water will be used for. Some people only filter their drinking water while others like to have filtered water throughout the home.

Take water pressure into account — some filters can reduce the flow significantly. If you want to create a more eco-friendly home, a ceramic filter is an excellent choice.

4. Maintenance

Water filters are intended to purify your water, but a poorly maintained filter can do more harm than good. It is crucial that you follow the manufacturer’s instructions on how and when to properly clean it. Some filters require regular replacement (9).

When handling the filter, ensure you wear gloves and wash your hands thoroughly afterward. As filters collect bacteria, viruses, and contaminants from water, you need to stay protected. People with compromised immune systems shouldn’t handle filters at all.

FAQs

Are Water Filters Good for You?

Water filters are good for you because they help remove different types of contaminants from the water. Because the filters eliminate the chlorine and germs that can make tap water taste flat or chemical, filtered water has a fresher and cleaner taste.

Since the filter eliminates potentially hazardous chemicals from the water, such as lead, using it is unquestionably beneficial to your health.

What Are the Two Most Common Water Filtration Systems?

Granulated activated carbon and reverse osmosis are the two most common water filtration systems utilized most frequently today.

In water purification, reverse osmosis refers to passing contaminated water through a membrane designed and constructed to have very small pores.

Water molecules and a few very small impurities are the only things that can pass through these pores. The vast majority of contaminants and undesired particles are trapped on the other side and eventually eliminated.

Activated carbon is quite successful in getting rid of the chemicals and compounds that give tap water its bad taste and odor. It is not as good at getting rid of other impurities.

These include fluoride, which the US uses to treat water, heavy metals and mineral ions that contribute to the hardness of the water, nitrates, and microorganisms.

Which Contaminants Are Not Removed by a Filter?

Water filtration is an efficient method for removing a wide variety of impurities. Still, there is no such thing as a water filter that can get rid of everything.

The residue left behind is determined by the type of filter used; for instance, ultraviolet (UV) filtration is ineffective in murky water and activated carbon filters do not remove microbiological pollutants.

Some different treatment approaches are employed in the most advanced filtering system.

What Kind of Water Filter Removes Chlorine?

Systems of water filtration that utilize reverse osmosis and combine carbon block filters are proven to be an efficient method for removing up to 98 percent chlorine from water.

A carbon prefilter will protect the sensitive reverse osmosis membranes from being damaged by coming into contact with chlorine during filtration. It will also absorb chlorine as it passes through the system.


Stay Safe

Water is essential for all life on our planet, including our own, but impure water can do more harm than good. Water filters provide an easy way to ensure you and your family have clean H2O to drink.

Bad tastes or smells and the risk of lead contamination are among the leading reasons to install a water filter. Many types of water filters will be able to clean your water, but it is essential to choose one that is suitable for you and your home.

Consider why you need the filter and what impurities might be in your water supply — this will make it much easier to determine what type of water filter is best for you.

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About the Author

Peter Gray

Peter has been a homeowner for 35+ years and has always done his own repair and improvement tasks. As a retired plumber, Peter now spends his time teaching others how they can fix leaks, replace faucets, and make home improvements on a budget.