Key Features
Compact unit that includes the water softener and brine tank all in one unit, making it easier to install and maintain. Certified by NSF/ANSI to standard 44 for hardness reduction. Removes up to 10 ppm of dissolved iron.
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Best Whole House Water Filters - NSF Certified
- by Ryan Moreau / updated: June 22nd, 2024
Water Filter Review Process
This review article discusses the different types of Whole house water filters used for common contaminants in your water.
Our primary goal is to answer one question: does the filter do what it says it will do?
1. Number of contaminants the filter claims to remove
2. Quantity and quality of 3rd party certifications verifying contaminant reduction claims
3. Supporting testing data that verifies contaminant reduction rates
These three criteria are essential in determining if you are purchasing a high-quality filter.
Filters we recommend have the highest level of certifications to back up their claims and are either directly certified by NSF or they are certified to NSF standards by a reputable 3rd party organization such as the Water Quality Association (WQA) or the International Association of Plumbing and Mechanical Officials (IAPMO)
Our Top Picks
This filter is certified by NSF to remove or reduce/remove calcium and magnesium hardness. For more details on removal rates see the Performance Data Sheet.
This filter was tested and certified by NSF to NSF/ANSI Standard 44 for the claims specified on the Performance Data Sheet.
NSF/ANSI 44 – Water Softener Certification for Removal of Calcium and Magnesium Hardness
Water softener resin is generally replaced every 10 years. Resin that is exposed to high levels of chlorine used in city water or iron that is usually present in well water will have a significantly lower life. A pre-filter to remove chlorine or an iron filter to remove iron should be considered in these situations.
Automatically calculates how much salt and water is needed to regenerate the resin beads each cycle. The following guidelines can be used to estimate how often your softener will regenerate based on incoming water hardness. At the maximum salt dose, this unit uses 37.1 gallons of water and 15.5 lbs of salt per regeneration.
At 120 ppm or 7.0 grains of hardness….
- 4 person family – Softener will regenerate every 12 days using approximately 93 gal of water and 38.75 lb of salt per month
- 5 person family – Softener will regenerate every 9.5 days using approximately 115 gal of water and 48 lb of salt per month
- 6 person family – Softener will regenerate every 8 days using approximately 140 gal of water and 60 lb of salt per month
At 180 ppm or 10.5 grains of hardness….
- 4 person family – Softener will regenerate every 8 days using approximately 140 gal of water and 58 lb of salt per month
- 5 person family – Softener will regenerate every 6.5 days using approximately 175 gal of water and 72.5 lb of salt per month
- 6 person family – Softener will regenerate every 5.3 days using approximately 210 gal of water and 87 lb of salt per month
At 240 ppm or 14 grains of hardness….
- 4 person family – Softener will regenerate every 6 days using approximately 189 gal of water and 78 lb of salt per month
- 5 person family – Softener will regenerate every 4.8 days using approximately 232 gal of water and 97 lb of salt per month
- 6 person family – Softener will regenerate every 4 days using approximately 278 gal of water and 116 lb of salt per month
Pros
- Inexpensive
- All in one unit that is compact and easy to install
- NSF Certified
- Regenerates based on demand for the most efficient water and salt usage
- Removes up to 10 ppm iron
- Clear Water iron setting – when activated initiates an additional backwash and fast rinse cycle prior to regeneration
Cons
- No prefilters to remove chlorine or sediment
- Claim iron reduction is substantiated by 3rd party laboratory data but we have not found this data
- Iron exposure is generally not good for softener resin and can greatly limit the life span. More frequent cleaning is necessary if iron levels are particularly high. For iron removal, the only filters we could find that were certified by WQA were the Culligan filtration systems. Check those out here
Key Features
Great NSF Certified low-cost option for smaller families. Compact and easy to install, making it ideal for installation in homes with limited space. Reduces hardness and iron up to 3 ppm.
This filter is certified by NSF to remove or reduce/remove calcium and magnesium hardness. For more details on removal rates see the Performance Data Sheet.
This filter was tested and certified by NSF to NSF/ANSI Standard 44 for the claims specified in the Performance Data Sheet.
NSF/ANSI 44 – Water Softener Certification for Removal of Calcium and Magnesium Hardness
Water softener resin is generally replaced every 10 years. Resin that is exposed to high levels of chlorine that is typically used in city water or iron that is usually present in well water will have a significantly lower life. A pre-filter to remove chlorine or an iron filter to remove iron should be considered in these situations.
Automatically calculates how much salt and water is needed to regenerate the resin beads each cycle. The following guidelines can be used to estimate how often your softener will regenerate based on in-coming water hardness. At the maximum salt dose, this unit uses 26.4 gallons of water and 10.8 lbs of salt per regeneration.
At 120 ppm or 7.0 grains of hardness….
- 1 person family – Softener will regenerate every 21 days using approximately 38 gal of water and 15 lb of salt per month
- 2 person family – Softener will regenerate every 10.5 days using approximately 76 gal of water and 30 lb of salt per month
- 3 person family – Softener will regenerate every 7 days using approximately 115 gal of water and 45 lb of salt per month
At 180 ppm or 10.5 grains of hardness….
- 1 person family – Softener will regenerate every 14 days using approximately 56 gal of water and 23 lb of salt per month
- 2 person family – Softener will regenerate every 7 days using approximately 112 gal of water and 46 lb of salt per month
- 3 person family – Softener will regenerate every 4.6 days using approximately 172 gal of water and 70 lb of salt per month
At 240 ppm or 14 grains of hardness….
- 1 person family – Softener will regenerate every 11 days using approximately 72 gal of water and 30 lb of salt per month
- 2 person family – Softener will regenerate every 5.5 days using approximately 144 gal of water and 60 lb of salt per month
- 3 person family – Softener will regenerate every 3.5 days using approximately 226 gal of water and 93 lb of salt per month
Pros
- Very Small and easily fits in small homes and apartment buildings
- NSF Certified
- Demand-based regeneration
- Removes up to 3 ppm iron
Cons
- No prefilters to remove iron, sediment, and chlorine
- Like the larger Whirlpool filter, we were unable to find data to back up iron removal claims. This does not mean they are not true.
- For WQA-certified iron filters, visit the Culligan site
Key Features
Uses calcite media to treat corrosive water by raising the pH, alkalinity, and hardness. Upflow design means that backwash not is required for this filter and water usage is lower. The unit contains a gravel layer to remove sediment followed by a calcite layer to increase pH. Calcite can be effectively combined with flomag/corosex to allow a higher increase in pH for lower pH level water.
The sediment filter section will remove large particulate matter that can be found in well water systems.
The calcite media does not remove any contaminants. When water flows through this unit, low levels of calcium carbonate are dissolved in the water. This increases the level of calcium hardness as well as alkalinity. The increased levels of alkalinity also increases the pH, reducing the overall corrosion of the system. If you need this system to increase the pH in your water, the slight increase in hardness levels will usually not result in needing a water softener.
Purchase NSF 60 certified calcite filter media for replacement.
NSF/ANSI 60 – Establishes the minimum health-effect requirements for chemicals, chemical contaminants and impurities that are directly added to drinking water from drinking water treatment chemicals.
Dependent on incoming water characteristics and usage. Once per year is common.
Pros
- Reduces the effects of corrosive water by increasing the alkalinity, hardness, and pH of water by dissolving calcium carbonate
- Increases the Langliers Saturation Index (LSI), a much better indicator of corrosivity than just the pH value
- Media replacement is inexpensive
- Calcite can be combined with Corosex, a magnesium oxide media for pH values below 6.0
- Simple upflow design means no backwash is needed
- Uses safe to use naturally occurring minerals and not potentially harmful chemicals
Cons
- There are no pH neutralizers that carry certifications for performance.
Key Features
High-capacity UV filter that can handle up to 18 gallons/minute flow or approximately 5 bathrooms. NSF certified to inactivate cryptosporidium, giardia, e.coli, and fecal coliform. The controller will notify you when it is time to replace your bulb. Generally used in well water systems where water is not chlorinated.
Reduces microbial contaminants ranging from protozoan cysts to viruses by using UV light waves to deactivate the DNA of microorganisms, preventing further reproduction and clean safe drinking water. Inactivates cryptosporidium, giardia, e.coli and fecal coliform
This filter was tested and certified by NSF to NSF/ANSI Standard 55 for the removal of microorganisms, viruses, and cysts.
NSF/ANSI 55 – Ultraviolet treatment systems that kill bacteria, viruses, and cysts.
UV bulb needs to be changed out every 12 months minimum. The controller will notify you when the bulb needs to be replaced.
Pros
- NSF 55 Certified to reduce microbiological contaminants
- The controller notifies you when its time to change the UV bulb
- High capacity, can be used for up to 5 bathrooms
- Low footprint
- High UV dose delivery at 30 mJ/cm²
Cons
- UV does not remove biological contaminants but kills them so that they can’t reproduce, dead bacteria can still affect taste. Post-filtration could be desired.
- Installation may be complex as additional fittings are necessary to connect to your water line.
Key Features
Softens water using Template Assisted Crystallization, a process that does not actually remove hardness ions but alters their structure to keep them dissolved in solution. Inexpensive when compared to others on the market from a reputable company. No salt and no brine tank are required.
None. Alters the structure of hardness ions, keeping them dissolved in solution.
Water Conditioners do not currently carry any 3rd party certifications.
6 years or 600,000 gallons.
Pros
- No Salt required
- Healthy minerals calcium and magnesium stay in the water
- Less Maintenance
- Reduces scale associated with hard water
Cons
- Difficult to verify if it is actually working
- No 3rd party certifications
- Does not prevent scale formation entirely, traditional water softeners are likely to give you better results
Key Features
NSF Certified for particulate reduction. Ideal for well water sources or city water sources that have a lot of sediment. Typically used before a softener or other whole house filter to prevent sediment from building up in the filter as well as your plumbing and appliances.
Visible sediment such as dirt, sand, and silt.
This filter was tested and certified by NSF to NSF/ANSI Standard 42 for the removal of particulate sediment.
NSF/ANSI 42 – Reduction of aesthetic contaminant concerns.
Filter cartridges are sold separately for this unit. Filter life depends on cartridge, typically you can expect the cartridges to last 3-6 months.
Pros
- Clear housing is a great visible indicator of when the filter needs to be changed out.
- Includes a bypass valve that allows you to change filters without shutting off the water
- One of the few sediment filters that are NSF Certified for particulate removal
- Multiple filter options
- Inexpensive option to prevent sediment from fouling other whole home filters and appliances
Cons
- A larger unit may be needed for bigger families or wells with excessive sediment
- Only removes sediment, a carbon filter is suggested if your water is chlorinated and you are using a softener
Key Features
The Aquasana Rhino whole home system reduces chlorine and other contaminants for your whole home using catalytic carbon and KDF media to prevent biological growth. Ideal for protecting your softener resin, drinking water, and shower water without any drop in pressure. Upgrades are available for higher capacity, UV filtration, and a salt-free water conditioner.
This filter is certified by NSF to remove chlorine and generally best used for pretreatment for softener systems to extend the life of the softener. For more details on removal rates see the Performance Data Sheet.
NSF/ANSI Standard 42 to remove up to 97% of chlorine and the Rhino® tank is WQA certified to NSF/ANSI/CAN Standard 61 the claims specified on the Performance Data Sheet.
NSF/ANSI 42 – Reduction of aesthetic contaminant concerns such as chlorine, taste and odor, and chloramine.
NSF/ANSI 61 – Certification of the pipes, gaskets, and meters utilized for water delivery are drinking water safe.
Filter life options available are 6 years (6,000,000 gallons) or 10 years (10,000,000 gallons) for the Rhino max version.
For larger homes, the Rhino® Max Flow boasts a 14.5 gallons/minute peak flow rate — perfect for larger homes and those seeking maximum performance.
Pros
- Removes chlorine and other contaminants from drinking water and wash water
- Ideally installed before a softener to protect softener been resin from chlorine degradation. Greatly extends softener life.
- Filter media can last up to 10 years
- No drop in water pressure
- Upgradeable to include sediment removal as a prefilter
Cons
- Higher chance for bacteria growth in areas of the house that do not use water as often. Should be installed with a bypass so the homeowner can run chlorinated water through the entire house periodically.
- Expensive and bulky. More difficult to change out filter media.
- Not certified for anything but chlorine. This does not mean it does not remove other contaminants but the main focus of whole home units is typically to remove chlorine before a water softener.
- Requires plumber or plumbing experience for installation.