Complete Guide to Home Water Filters

by Ryan Moreau / updated: April 23rd, 2024

Thinking about buying a water filtration system for your home? In this step-by-step guide, we’ll help you determine the the best water filtration system to produce safe high quality drinking water for your home and family.

Let’s get started!

Important Questions To Ask

Choosing a water filtration system that meets your needs can seem daunting. Filter technology has expanded over the years, and the number of options on the market can be overwhelming. Several companies are competing for your business, and it can be difficult to determine which ones to trust. When thinking about how to organize this guide, we decided to break it down into the three most important questions to consider when buying a water filtration system. Click on each section or sub-section below if you want to skip ahead!

Do You need a Water Filter?

In the United States, we are fortunate to have some of the highest quality water in the world right out of our tap. The first and most important question you should be asking is, do you even need a water filter? If you are reading this guide, this is a question that you likely need help answering. There are many reasons that people buy water filters. In general, people who purchase water filtration systems fall under one of the three categories detailed below.

Remove Water Contaminants

Water Contaminants?! What water contaminants? I know, know…. we just covered how fortunate we are to have such amazing water quality here in the United States. While this is true by most standards, this does not mean our water is entirely contaminant-free. Whether you have city water or use a private well, you should be aware of the potential for contaminants in your water. The EPA regulates and provides contaminant level guidelines for over 96 contaminants in public water systems. These contaminants can end up at your tap in a variety of ways. The good news is most of them can be removed relatively inexpensively with a simple water filtration system. In this guide, we’ll help you determine if your water has any of these contaminants and show you how to remove them!

Improve Taste

Not all contaminants found in your water are directly hazardous to your health. However, many contaminants in drinking water can make your water taste off! Do you find that your water tastes like a swimming pool or has a noticeable chemical, earthy, or metallic taste? You may even notice a rotten egg smell or a fishy taste if you have well water. Not only is this hard to drink, but some of these bad tastes can indicate that your water is unsafe to drink! If you are having a hard time stomaching your water, some simple filtration options are available.

Protect Plumbing and Appliances

Water has varying levels of dissolved minerals depending on where you live. These minerals, such as calcium, magnesium, sodium, and potassium are essential to a healthy diet. However, some of these minerals, specifically hardness-related minerals like calcium and magnesium, may leave troubling deposits that can damage your household plumbing and appliances. These deposits will appear in your shower and on your glassware as a white film. They form hard deposits in your water heater, dishwasher, and other household appliances, reducing their efficiency and lifespan. Hard water can also cause dry skin and hair and make it difficult to get laundry clean.

You may also live in an area with very low hardness and mineral content. Water with low mineral content can be very corrosive, causing damage to plumbing that can lead to water leaks in your house. Corrosive water also poses a significant health risk as harmful metals from the plumbing can leach into your water.

Those affected by hard or corrosive water generally need a whole home water filtration system to protect their plumbing and appliances.

What's In Your Water?

Now that you know why people purchase water filters, let’s find out if you need one! To determine if you need a filter, you must first understand what’s in your water. Below, we will walk you through three ways to determine your water quality.

TapTool Water Quality Report

The best way to get started is to use our TapTool application and enter your zip code and water source (city or well). TapTool combines local drinking water and pollution data to generate a comprehensive water quality report unique to you. The data provided in TapTool will help you determine areas where your water may be deficient or at risk for contamination. You can find out more about how we gather data for TapTool here.

Consumer Confidence Reports

If you’re like us, you prefer to have multiple sources of information before making any decisions. Another great resource is your public water system’s Consumer Confidence Report (CCR). The CCR is a water quality report that the EPA requires your public water system to issue annually. Unfortunately, there is no standard for the formatting and data presented in these reports. Finding these reports can also be difficult as the EPA does not maintain a working database for them. The best way to find them is by simply googling your public water system name or city name followed by “Consumer Confidence Report” or “Water Quality Report.”

You can find your public water system name by entering your zip code into TapTool. The most complete CCRs will show you various contaminant levels in your water and note any recent violations. Less complete CCRs typically have very little information and will only report if the utility is in compliance without sharing actual data. Depending on where you live, the CCR may or may not be an excellent source of information.

Water Testing

The only way to truly know what’s in your water is to test your water right out of the tap. You can do your own testing at home, or you can send water samples to an outside lab to have more comprehensive testing done. SimpleLab is an excellent testing resource that sells sample kits for city and well water. If you are on well water, we recommend testing your water once a year. If you prefer to do your testing at home, check out our water testing guide. The testing guide will walk you through tests you can do inexpensively at home and also cover more comprehensive lab testing. At-home tests can help you understand the general characteristics of your water and can give you an idea of contaminant potential. Unfortunately, not all tests can be done at home, and for the complete picture, you will need to send off samples.

What Type Of Water Filter Should You Get?

Now that you know what’s in your water, it’s time to decide what contaminants you would like to remove or reduce. Your TapTool report provides filtration recommendations for the specific contaminants in your water, so make sure to look if you haven’t already. In this section, we will go into greater detail on each type of home filter and what they are used for.

NSF Certifications

Before purchasing a water filter, it is essential to determine whether the filter will remove the specific contaminants it says it will. This is where NSF Certifications come in. An NSF certification allows manufacturers to choose which contaminants their product will reduce, and NSF independently verifies that their filter will do what it says it will do. Because these standards allow manufacturers to certify their products to reduce various contaminants, it’s important to check the packaging for both the standard name (such as NSF/ANSI 53 or NSF/ANSI 58) AND a claim for specific contaminant reduction. Once you understand what is in your water and what you want to remove, you must select a filter certified by NSF to remove that contaminant.

Below is a summary of all NSF Certifications for home water filtration systems that you can use as a reference.

NSF/ANSI 42

Reduction of aesthetic contaminant concerns such as chlorine, taste and odor, chloramine, particulate, iron, manganese, zinc and total dissolved solids (TDS).

NSF/ANSI 44

Water softener certification for removal of calcium and magnesium hardness.

NSF/ANSI 53

Over 50 health-related contaminant reduction claims. See the manufacturer’s specifications for specific contaminants.

NSF/ANSI 55

Ultraviolet treatment systems kill bacteria, viruses and cysts.

NSF/ANSI 58

Reverse osmosis (RO) water treatment systems that remove a wide range of contaminants.

NSF/ANSI 62

Distillation systems that remove a wide range of contaminants.

NSF/ANSI 177

Shower filters that remove chlorine and other contaminants from shower water

NSF/ANSI 244

Bacteria and virus removal for public water systems in the event of water contamination resulting in a boil order.

NSF/ANSI 401

Removal of 15 specific contaminants related to prescription drugs, over-the-counter medications, herbicides, pesticides and chemical compounds.

NSF/P231

Removal of bacteria, viruses, and cysts.

NSF/P473

Remove per- and polyfluoroalkyl substances (PFAS) from drinking water.

NSF/P477

Reduction of microcystin

NSF/JWPA P72

Reduction of iodine

In the next section, we’ll review each type of filter and all the possible certifications you should look for based on the contaminants you would like to remove. Please note not all filters of the same type will always have the same certifications.

Activated Carbon

Activated Carbon Filter’s are the most common water filter homeowners use. These filters are constructed using either granular activated carbon or a carbon block. Water is passed through a cartridge filled with this carbon material, and contaminants are removed via adsorption. Carbon filter’s are often used to improve the taste and odor of water by removing chlorine, heavy metals, and contaminants that can contribute to poor taste and smell.

Filter Cartridge with Coconut Shell Carbon

Certifications

Minimum: NSF/ANSI 42, 53
Others: NSF/ANSI 177, 401, P473, P231, P473, P477, JWPA P72

Costs

Whole Home Systems: $500 – 5,000
Point-of-use Systems: $50 – 500

Companies

Aquasana, Brita, Pentair, Apec Water Systems, Berkey, Clearly Filtered, Springwell, WaterDrop

Filter Cartridge with coconut shell carbon.

Installation Options

Under-Sink, Faucet, Fridge, Countertop, Shower, Whole Home

Replacement Life

Point-of-use: 3 – 6 months
Whole Home: 5 – 10 year

Contaminants Removed

If you have decided a carbon filtration system is right for you, check out our Carbon Filter Buyer’s Guide for a more detailed review of specific systems.

Reverse Osmosis

Reverse osmosis (RO) systems are the best option for maximum contaminant removal. These filters remove 95-99% of the dissolved salts (ions), particles, colloids, organics, bacteria and pyrogens from your drinking water (although an RO system should not be relied upon to remove 100% of bacteria and viruses). Contaminants removed from reverse osmosis are removed via a reject stream that needs to be plumbed to a drain when installed. Due to the low flow of the purified water, RO units will typically come with a 2-5 gallon storage tank that will take anywhere from 1-3 hours to fill.

Most RO systems will come with both a sediment and carbon pre-filter to extend the life of the RO filter. The sediment filter removes large particulate matter that can plug the filter membranes. The carbon filter removes chlorine as chlorine can damage RO membranes and drastically reduce the filter life. Since RO systems remove nearly all dissolved solids in your water, they also remove essential minerals naturally occurring in your water. Many RO systems come with remineralizers to add these minerals back into your water to improve the pH balance and water alkalinity for healthier water. When buying an RO system, buying a system equipped with remineralization is best to avoid having corrosive, mineral-deficient water.

Typical RO Filter set-up with cross section shown.