Water Filters FAQs
Find answers to your most common questions about water filter selection, performance and maintenance, backed by NSF’s decades of experience in water treatment technology testing and certification.
Why should I have a water filter?
An NSF-certified water filter helps reduce contaminants that a consumer may not want to consume.
How can I tell if a water filter is certified?
Certification marks will typically be present on product packaging, with more information on what the certification mark covers on the manufacturer’s website. To verify the third-party certification further, consumers can check the certification body’s website to ensure that the product is, in fact, currently certified. For NSF-certification, check NSF’s Products Listing Page.
What chemicals or contaminants do water filters remove?
The contaminants a water filter will remove vary from product to product. It is important to begin by determining what contaminants are in your water by viewing your local water quality report and searching for a filter from there.
What are PFAS/microplastics? Can water filters remove PFAS or microplastics?
PFAS are man-made chemicals that have been used throughout the years in many manufactured products due to their durability and ability to repel water, oil and heat. They are difficult to break down in nature and our bodies, earning their name “forever chemicals”. Water filters certified to NSF/ANSI 53 or NSF/ANSI 58 with a PFAS designation help to filter out PFAS.
Microplastics are extremely small synthetic particles or polymeric matrices that are insoluble in water, which makes them more prevalent in our environment and our bodies than ever before. Water filters certified to NSF/ANSI 401 helps to reduce these contaminants.
What’s the difference between a water filter, purification or treatment system?
Water filters are the most common household water improvement solution. These systems work by physically removing contaminants through various mechanisms.
Water purifiers target biological contaminant reduction. These systems often combine multiple treatment technologies.
Water treatment systems often address multiple water quality issues simultaneously. These systems may modify water chemistry, remove contaminants, and condition water for specific uses.
What is the right water treatment solution for my home?
There is a broad range of technologies, configurations, sizes, and price points for water filters. The type of water filter someone prefers will differ from consumer to consumer, depending on what they want to filter out, how they would like the filter to be installed or used, their budget, and other factors.
How often should I change my water filter?
It is important to properly maintain a water filter and ensure the replacement filters are switched out per the manufacturer’s instructions.
What is a Consumer Confidence Report?
A Consumer Confidence Report, or Water Quality Report, is a localized report that water utilities release that detail the specific contaminants and their levels in the local water. Consumers should first check their local water quality report to find out what exactly is in their local water that they would like to filter out and select a water filtration device that can remove those things.
