Selecting a Home Water Treatment System

How do you know if you need a water filter or a water purification or treatment system? What can you do to find the best filter for your home and where do you start? We have these helpful and important steps to find the right water treatment solution for your home. We test filters and treatment systems for safety and performance to provide assurance that a certified product will do what it says it is going to do.

Step 1: Find Out What Is In Your Water

If you are wondering what contaminants may be in your water, you can start by getting a copy of your water quality report (called a CCR or consumer confident report) from your local water utility/authority (in the U.S. and some cities in Canada). If you are unable to get your report or if you have a private well, you may want to consider having your water independently tested.

Step 2: Decide What Contaminants You Want to Reduce

Once you know what contaminants are in your water, you can better find a treatment solution that is certified to address your water quality concerns.

It’s important to understand that not all filters can reduce all contaminants. Based on the water report or your water testing results, you can decide what contaminants you want to reduce in your drinking water. NSF’s contaminant selection guide will help you to locate products that are certified to reduce specific contaminants.

Step 3: Compare Options for Water Treatment

A number of water treatment solutions are available. They range from whole-house systems that treat all the water in your home, to filters for specific areas such as the kitchen faucet, to more portable solutions such as a water pitcher or even countertop filters. Some reduce only one contaminant while others reduce many.

  • Point-of-use (POU) systems treat the water where you drink or use your water, and include water pitchers, faucet filters and reverse osmosis (RO) systems. Reverse osmosis systems are the only NSF certified systems that reduce fluoride and nitrate; and Reverse Osmosis systems are the only ones that are NSF certified to reduce both lead and copper.
  • Whole-house/point-of-entry (POE) systems treat the water as it enters a residence. They are usually installed near the water meter (municipal) or pressurized storage tank (well water). Whole-house treatment systems include UV microbiological systems, water softeners or whole-house filters for chlorine, taste, odor and particulates.

Visit our listings for NSF-certified versions of these products:

Point-of-Use Filters

Whole-House Filters

Additional Information

What Are NSF’s Drinking Water Standards?

NSF certifies drinking water filters to standards applicable to each type of treatment option. You may notice the NSF mark on a product along with numbers such as NSF/ANSI 53 or NSF/ANSI 42, which refer to the standard to which the filter has been certified. Manufacturers choose which contaminants their product will reduce and NSF International verifies that their filter will do what it says it is going to do. Because these standards allow manufacturers to certify their products to reduce a variety of 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 such as lead.To review the protocols and NSF/ANSI standards that cover home water treatment systems, visit Standards for Water Treatment Systems.

Replacing Your Filter

Once you have decided on a home water treatment system, it will need regular maintenance to operate properly. Remember to replace your filter when required. Some filters have indicator lights and some may recommend time ranges for replacement. Familiarize yourself with the replacement requirements of your water treatment system. Be sure to include the ongoing cost of replacement filters in your final budget for a home water treatment solution.