3M Aqua Pure AP904 Review – Whole House Water Filtration and Softener System

by Curtis Grossi | Last Updated: March 13, 2024

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If you’re looking for an all-in-one whole house filter that removes sediment, odors, and scale in areas supplied by hard city water or low sediment well water, the 3M Aquapure AP904 Whole House Water Filtration and Softener System is an ideal solution.

It will improve water quality and taste while helping to protect your home’s hot water heaters, water-using appliances, and plumbing fixtures from scale build-up.

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It has a Sanitary Quick Change (SQC) feature that allows you to change the compact AP917HD-S filter easily and with almost no spillage or mess. No need to use a wrench or a screwdriver, the filter housing makes a secure, waterproof seal when installed, but twists out easily when it’s time to replace the filter.

The multi-purpose filter is sealed into the blue filter housing and the whole housing gets replaced, so there is no need to open the housing in order to remove a dirty used filter, just replace the whole cartridge.
The stainless steel AP900-series head unit is durable and corrosion-resistant and will give a long lifetime of service. With a flow rate of 10GPM (37.85 liters/minute), the 3M AP917HD-S filter unit delivers enough safe, crystal clear, soft water for a home with up to two and a half bathrooms.

The scale inhibitor function of the AP917HD-S filter cartridge means it is not necessary to pre-treat water with a moderate amount of water hardness with a separate water softener.
The materials making up the whole house water filtration system are FDA CFR-21 compliant and are safe for drinking water and food.

Who Is 3M?

3M is a world-renowned company with a solid reputation for quality and service. The Minnesota Mining and Manufacturing Co. (3M) began as a small-scale mining venture in 1902, and its technical and marketing innovations in a wide variety of materials and products since then has led to the company it is today.

In the 1970’s and 1980’s, 3M expanded its market focus into pharmaceuticals, radiology and energy control, and currently 3M is responsible for 60,000 products used in businesses, homes, hospitals, schools and other sectors, having earned its 100,000th patent in 2014.

Important Features

1. Safe Quick Change (SQC) Design​

The SQC design of the filter attachment mechanism allows for fast and easy filter cartridge change-outs by hand, without the need for a filter wrench. The replacement of the whole filter cartridge, rather than the filter itself, reduces water spillage and mess, and provides for an improved the hygiene standard during the change-out process.​

2. FDA CFR-21 Compliant Materials

The materials used in the manufacture of the 304 stainless steel water filter head and the filter cartridge are FDA CFR-21 compliant and food and drinking water safe.

3. Multi-purpose Water Filter and Softener

In addition to scale inhibition media that help prevent build-up of scale in pipes and water-using appliances, the AP917HD-S water filter cartridge design incorporates carbon block filtration and non-woven pleat media that exclude sediment down to 5 microns while also reducing chlorine taste and odor.

Water softening is achieved by binding calcium and magnesium using polyphosphates in minute quantities so they do not precipitate out and build up scale on metal surfaces.
The binding process also prevents the water hardening minerals from reducing the water’s ability to produce soap suds.

Note that the 3M Aquapure AP902 and AP903 Whole House Water filter systems are supplied with filter cartridges that do not reduce water hardness, but the filter heads are compatible with the AP917HD-S water softener filter cartridge, which can be installed as a replacement filter.

Water Capacity, Pressure, and Temperature Range

The 3M Aqua-Pure AP904 water filter head with an AP917HD-S cartridge will deliver a maximum flow rate of 10GPM (37.85 liters/min).

The pressure range of the system is between a minimum of 25psi (172kPa) and 125psi (862kPa), and its operating temperature range is from 40°F (4.4°C) through 100°F (37.8°C).

Power Rating Consumption

The AP904 does not use electricity, so no power rating is applicable.

Water and Salt Consumption

The AP904 water filtration and softener system is rated at a treatment volume of 100,000 gallons (378,500 liters), but the filter cartridge should be replaced when there is a noticeable drop in household water pressure.

For moderate water quality, this may be once a year, but in areas with poor quality water replacement might be required more frequently. 3M recommends that the filter is replaced at intervals of no longer than 12 months.

The AP917HD-S water filter does not use salt for water softening but incorporates scale inhibiting polyphosphates in minute quantities that bind calcium and magnesium hardness minerals to prevent them from precipitating out and building scale on metallic surfaces.

Size, Dimensions and Shipping Weight

The entire water filter unit including head and filter cartridge is 25.2” (63.7cm) high and has a maximum diameter of 4.5” (11.4cm). Its shipping weight is 10.2 lbs (4.6kg).
The filter head has 1” NPT threaded socket fittings.


  • A very affordable system;
  • Made from good quality food and drinking water safe materials;
  • Multi-purpose water filter and softener;
  • The system is simple to install;
  • The filter cartridge is easy to replace;
  • No addition of salt is required;
  • The system doesn’t use electricity.


  • Limited water hardness treatment capacity;
  • No light or volume monitor to indicate elapsing of replacement period;
  • AP917HD-S filter cartridges are relatively expensive;
  • A pre-filter is necessary if the system is used for high sediment well water.

Price Range

The 3m Aqua-Pure AP904 Whole House Water Filtration and Softener system with scale inhibitor can be obtained for a price in the US$300 to US$400 range.

3M Aqua-Pure 900 Series Installation (video)


3M gives a 25-year limited warranty on the stainless steel head component and a one-year limited warranty on the AP917HD-S filter cartridge component of the Aqua-Pure AP904 water filtration and softener system.


Most customer reviews of the 3M Aquapure AP904 Whole House Water Filtration and Softener System are strongly positive. Customers generally appreciate the sturdy build of the system, the good quality of water produced, the simplicity of installation and the low maintenance aspect of the system, as well as the ease with which filter cartridges can be replaced.​

There are, however, several complaints about the cartridge clogging up sooner than expected, but as is pointed out in some comments, the system is not meant for high sediment water sources such as well-water, or water with a high degree of hardness.

The solution suggested by most comments is to install a clear spin-down sediment filter, or a 5-micron sediment filter with cheap replacement cartridges, before the Aquapure system in the water input line in order to remove most of the larger sediment particles.

It is also recommended that a shut-off valve is installed on either side of the system to reduce the amount of water spilled when changing the filter cartridge.


The 3M Aquapure AP904 Whole House Water Filtration and Softener System is a robust, user-friendly water softener and filter that will protect your household plumbing and appliances from scale build-up, while providing you with soft, clean, odor-free drinking water with a minimum of fuss and bother.

It will suit people who want to avoid the burden of having to load salt into their water softener every week or so. Its sturdy construction, easy installation, and low maintenance features make it a great product for those who want to ‘set and forget’. The relatively long filter replacement intervals and Safe Quick Change (SQC) filter cartridge replacement procedure make it a pleasure to use.

If the replacement intervals appear to be shorter than expected, the lifespan of the filter can be extended by installing a spin-down or sediment filter in line ahead of the Aquapure system, but filter cartridges should be replaced at least once every 12 months.

3M is a world-recognized brand leader that provides a 25-year limited warranty on the filter head unit and a one-year warranty on the filter cartridge.
3M Aquapure AP904 Whole House Water Filtration and Softener System is a great option for those who would prefer to avoid sodium-based water softeners.

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Curtis is the founder and owner of softeningwater.com. He is the lead guy concerning all the water-softening accessories in this site's guides and reviews. If he is not writing a reviews, guides or any other useful tips, you will find him testing them to find out their suitability. He is passionate about softening water. You will find him extremely helpful and always willing to educate the general populace all there is concerning water and its effects on their health and appliances.