How to Choose a Water Filter for Your Home (No-Nonsense Guide)

Finding the right filtration system for your home is essential for clean, contaminant-free water. However, with so many types of filters on the market, how do you choose the right model for you?

In this complete guide, we walk you through everything you need to know to zero in on the right filter for your home, or whether you need a filtration system at all. Let’s get started.

Quick Look

If you don’t have the time to go through the whole article, here’s a quick look at the types of filters:

Buy a Whole House Water Filter if you:

  • Want to treat your entire water supply at the main source
  • Want fast filtration rate with very good efficiency
  • Have minimal maintenance and a longer lifespan

Buy an Under-Sink Water Filter if you:

  • Want clean water for drinking and cooking
  • Want more options for filtration (including reverse osmosis systems)
  • Are looking for a hidden filter that doesn’t take space

Buy a Shower Water Filter if you:

  • Need to target the removal of chlorine and hardness minerals
  • Don’t want to make a big investment
  • Want easy installation and instant filtration

Buy a Countertop Water Filter if you:

  • Want an affordable, portable option
  • Require an easy-to-install system
  • Are looking for effective contaminant removal

Buy a Faucet Filter if you:

  • Want a small device that purifies your water at the outlet
  • Don’t want to spend a lot of money on it
  • Want to switch between filtered and unfiltered water easily

Buy a Water Filter Pitcher if you:

  • Only want to treat your drinking water
  • Want an affordable and portable option
  • Want to effectively remove chlorine

A Quick Comparison of the Types of Filters

How to Choose a Water Filter for Your Home Table

Why Filter Water?

Although your water supply may appear clean, it’s highly likely that there are at least some contaminants in it. For example, city water typically has chemicals like chlorine and fluoride, added to the water to disinfect and fortify it. Well water, or other private water sources, are unregulated, and could have more harmful types of contaminants, like bacteria, viruses, lead and iron.

Also, even if the water comes from a clean source, it could collect contaminants as it journeys through your pipes. If you’re home has old pipes, these could leak lead and other harmful contaminants into your water.

Even regulated municipal water supplies can be subject to accidents, like the Flint, Michigan water crisis. There officials switched the water supply to the Flint River. The untreated water caused the pipes to corrode and leak lead into the water supply.

These kinds of events are very rare, so don’t let it scare you. But it does make a good case for having a quality water filter system installed in your home, so you know what’s coming out of your tap. It gives you peace of mind and control over your water.

What Do Water Filters Do?

Distilled water in glass

Clean or contaminated?

Filters work to remove contaminants in your water through a variety of methods and using a range of different filter mediums. Most comprehensive filtration systems utilize a combination of mediums to target the most contaminants.

The image below shows you some filtration mediums and the type of contaminants they remove.

  • Ultrafiltration This type of filtration method forces water through a membrane, which filters debris and microscopic contaminants. It’s a mechanical filter which can remove contaminants that are at the level of 0.025 micron.
  • Reverse Osmosis (RO)This system also uses membrane technology but differs from ultrafiltration in that RO separates inorganic dissolved materials from the molecules of the water. This molecule separation method removes almost all contaminants from the water.
  • Activated Carbon Block (ACB)One of the most commonly used filtration mediums, ACB is made of finely ground charcoal powder that’s mixed with a binder and compressed into a solid block. This gives it high adsorption capacity which makes it highly effective in removing a wide variety of contaminants, including sediment, chlorine, mercury, lead and biological contaminants.
  • Granular Activated Carbon (GAC) Also made from carbon (a.k.a. charcoal), GAC differs in that it’s made up of loose granules rather than a compressed block. As such, its filtration capacities are lower than ACB. However, GAC allows for higher flow of water which is why its typically chosen for shower water filters.
  • UV Purification – Some filters may include a UV purification stage. These are perfect for well water supplies which may have microorganisms in them. UV works to destroy pathogens and trace organics in water by attacking their DNA. It makes water safe to drink from biological contaminants but doesn’t filter water or remove other contaminants. UV purification is best used in collaboration with other filter mediums.

Water Filter Types

Keeping the above factors in mind, let’s take a look at the most popular types of filters on the market.

Whole House Water Filter

Whole house filter

A whole house filter is a POE system, designed to target your entire water supply. These models are installed at the main point of your water supply. They typically consist of a multi-stage process, incorporating a sediment filter followed by activated carbon filters. Whole house systems can last up to 15 years or more and require replacements every 6 to 12 months. While these systems remove the most obvious contaminants in your water, they don’t always remove biological contaminants. It’s best to pair a whole house filter with an under-sink water filter to ensure your drinking water is safe.

Check here for a list of the best whole house water filters and a comprehensive buying guide.

Under-Sink Water Filter

Under-sink water filters are smaller systems that are installed in the cabinet under your sink. They’re out of the way, take little space and typically use the cold water supply as the feed source. These systems work on demand and are POU systems. They only supply clean water to the faucet they’re connected to.

Under-sink water filters have a lifespan of 6 to 12 months but can last up to 5 years. These filters come in a variety of types, to suit a range of budgets and are perfect if you only want filtered water for drinking and/or cooking.

Check here for a list of the best under-sink water filters and a comprehensive buying guide.

Faucet Filter

Faucet water filter

Faucet filters are small devices attached to your faucet. They filter water when you turn on the tap and work on demand. These devices are not as effective as larger systems but are good if you want to target obvious contaminants and are particularly good at removing chlorine.

Faucet filters are affordable and easy to install. Most models also let you switch from filtered to unfiltered water, so you get the most out of your filter life. If you live in a rental property or are on a budget, a faucet filter is a good choice.

Check here for a list of the best faucet water filters and a comprehensive buying guide.

Shower Water Filter

Shower water filter

Shower water filters are installed either in-line or as a showerhead to target the water coming out of the shower. The main issue people have with shower water is hardness, which can cause dry skin, hair and lime and scale build up in the shower. Shower filters are designed to soften water to some extent, reduce chlorine and other harmful contaminants that affect your body. These filters are affordable, small and easy to install. They also tend to have relatively long lifespans, with some models lasting up to 6 months. 

Check here for a list of the best shower water filters and a comprehensive buying guide.

Water Filter Pitcher

Pitcher water filter

One of the most popular types of filtration systems on the market, a water filter pitcher is portable, affordable and surprisingly effective. Filter pitchers are designed to eliminate common culprits like chlorine, lead, mercury, nitrates and nitrites from water. Some filter jugs are certified to remove up to 250 contaminants, including pathogens.

Filter pitchers last a long time, but the filter itself will require replacing every 2-3 months. This type of filter is ideal if you only want clean drinking water, and they’re also economical as long as you keep usage at around 2 gallons. Over this and you’ll be better of putting in a system with larger filtration capacity.

Check here for a list of the best filter pitchers and a comprehensive buying guide.

Countertop Water Filter

Counter top water filter

Countertops are small filter systems that come with their own spout. They are placed next to the sink and are used mainly for drinking water. Countertop filters are compact and portable, easy to install and typically have long lifespans.

This type of filter is very effective at removing sediment, rust, debris, chlorine, heavy metals and fluoride, among other contaminants. But one issue is that they take up precious space on your countertop and can be intrusive. Regardless, they’re an easy way to quickly get clean water in your kitchen without a big investment.

Check here for a list of the best countertop filters and a comprehensive buying guide.

How to Choose Your Filter

When choosing your filter, there are several factors to consider. Here’s a look at the most important points.

POE vs. POU Water Filters

POE stands for point of entry and means that the filter is installed at the main point of your water supply. The water is filtered right at the start, and clean water is then sent through all the pipes to all the fixtures. This ensures that your entire water supply is treated before it enters your home. The best example of POE filters is a whole house water filter system.

POU stands for point of use. This refers to filters that are installed at the point of use and work with specific outlets. You might not want filtered water throughout your home, to fill up the laundry and toilets with, but you may want filtered water in your kitchen or the shower. POU filters are smaller in size and are located near the outlet. Some examples include shower water filters and under-sink filters. To choose between a POE or a POU, you’ll need to decide where you want filtered water.

Contaminant Removal

There are four main types of contaminants into which all the other 80+ impurities can be categorized. These are biological, radiological, physical and chemical contaminants. From these four types, the most common contaminants include:

  • Heavy metals like nickel, arsenic, lead and mercury
  • Pathogens like viruses, microbes and bacteria
  • Chemicals like chlorine and iodine
  • Minerals like calcium and magnesium
  • Pesticides, herbicides and pharmaceuticals
  • Sediment which is common in groundwater which percolates through sedimentary rocks.
  • Volatile Organic Chemicals (VOCs) are chemicals that vaporize into air or dissolve in water such as benzene or toluene
  • Radon

Once you know the types of contaminants in your water, you can determine the type of filtration medium you choose. To know what’s in your water, you may have to do a home water test or send a sample of your water to a professional laboratory. Additionally, if you’re using municipal water, you could request a water quality report which would detail the types of contaminants in your water and the treatments used.

Maintenance Costs

The main ongoing cost associated with water filters is the cartridge replacement. This varies depending on the filter type and its lifespan.


Most POU filters are smaller and easier to install whereas larger, more comprehensive systems may require a professional to get the job done. Factor in the costs of installation when budgeting for a filter system.


Filters range in size from inconspicuous to large systems. Consider the space in your home as this will factor when choosing your filter.

Water Supply

  • City water –Public water systems are well regulated and monitored. These typically give their customers an annual water quality report, which details the types of contaminnats in the water, the health implications and any treatments done on the water. If you have city water, the main contaminants to check for are chlorine (which impacts the taste and smell of the water) and lead.
  • Well water – If your water comes from a private source, the responsibility to make sure the water is safe depends on you. This type of water is untreated and so can have a wider range of contaminants, including harmful microorganisms, iron and lead. It’s also important to test your water periodically so you have a record of its water quality. This will come in handy in the event of a dispute or if someone has damaged your water supply.

Water Usage

How much clean water do you require? Knowing this will help you to choose the right filter for this capacity. For example, if you use more than 2 gallons of filtered drinking water a day, a filter pitcher will be more expensive than an under-sink water filter.


Larger filtration systems have longer lifespans, with filters that need to be changed every year or so, whereas smaller filters may require more frequent filter replacements. For example, an under-sink filter cartridge can last from 6 months to a year on average, whereas a faucet filter may need replacing every 2-3 months.


There are standards that apply to different water filters which are set by NSF International. This is an American product testing, inspection and certification organization accredited by the American National Standards Institute (ANSI). The Water Quality Association (WQA) and the International Association of Plumbing and Mechanical officials (IAPMO) are also testing organizations that routinely test water filtration products.

Some standards to watch out for are:

The standards to look out for are NSF/ANSI 42, 53 and 401.

  • 42 – This standard relates to the safety of the materials used in creating the filter. It also covers chlorine reduction including bad tastes and odors in the water.
  • 53 – This standard relates to health, covering a wide range of health-related impurities found in water, such as sediment, bacteria, lead, mercury, and rust.
  • 58 – This standard only applies to Reverse Osmosis systems, certifying that it removes TDS and dangerous contaminants.
  • 401 – This covers up to 15 chemicals and trace pharmaceuticals that may be present in water.

The issue is that many filters claim they have these certifications, but this doesn’t always mean that the filter fully meets the standards. A filter only has to be able to remove up to a certain amount of these contaminants to be awarded the certification. Some filter manufacturers simply claim they have certification when they do not. To make sure that these claims are real, you would have to check these on the databases of these certifying organizations.

Also note that some excellent water filters may not carry any certifications, simply because the manufacturers haven’t got the funds to certify the product. These certifications are expensive to acquire so a manufacturer may be still in the process of obtaining it while the product is already on the market.

The Bottom Line

When choosing the best filtration system for your home, it’s easy to get overwhelmed by the amount of choice available. The best option is to take it step by step, by first identifying what your water needs are and then purchasing the best filter to address those needs.

Here’s a quick recap of how to choose your filter:

  • Test your water and note what contaminants you want to remove
  • Decide where you want the filtered water – whole house or at a certain point of use
  • Choose the best filter type
  • Select the best filtration medium designed to remove the contaminants in question
  • If you want extra drinking water safety, opt for a combined filtration system like a whole-house water filter coupled with a drinking water filter like an under-sink filter
  • Monitor the effectiveness of your filter and replace filter cartridges as per the manufacturer’s recommendations

Hopefully this extensive guide has given you a clear indication of what you need to do to get clean water in your home.

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