PUREPLUS 5 Micron 20in x 4.5in Whole House Iron & Manganese Filter

In this review the PUREPLUS 5 Micron 20in x 4.5in RFN20BB replacement cartridge is evaluated for homeowners dealing with well water or visible iron staining. The bottom line: this cartridge is for anyone who needs targeted removal of iron and manganese from whole-house supply and values a reusable resin element that can be restored. The reviewer found the cartridge to be straightforward to install as a drop-in replacement in compatible 20in housings and particularly effective at lowering iron and manganese to very low levels when used as part of a three-stage system.

Key Features

• Iron and manganese removal: The reusable resin granule filter is designed to reduce iron from up to 3.0 ppm down to about 0.01 ppm and manganese from up to 1.0 ppm to about 0.01 ppm, improving water clarity and protecting plumbing fixtures.
• Reusable resin element: The inner resin granules can be regenerated by soaking in salt water for 12 hours, extending the cartridge life and reducing replacement cost.
• Long service life: The cartridge is rated for roughly 6 months or 4,000 gallons of use before replacement, whichever comes first, for predictable maintenance scheduling.
• Quality tested: Manufactured under ISO9001 standards and subjected to multiple production checks, 400 PSI pressure tests, and 10,000 water hammer tests for durability under household conditions.
• Whole house compatibility: Built for use in 20in x 4.5in whole-house housings and intended for a 3-stage filtration arrangement to protect downstream appliances and taps.

Who It's For

This cartridge is well suited for homeowners with private well water or municipal supplies showing elevated iron or manganese, and for families who want a whole-house solution rather than a point-of-use cartridge. Installers or DIYers who maintain a three-stage system will appreciate the targeted chemistry of the resin granules for iron and manganese reduction.

It is less appropriate for users needing multi-contaminant filtration in a single cartridge (for example sediment plus chlorine taste/odor combined) or for systems that require a different cartridge dimension or micron rating. Buyers should confirm compatibility with their 20in whole-house housings before ordering.

Pros & Cons

Pros

• Effectively reduces iron and manganese to very low levels when used as directed.
• Reusable resin can be regenerated with a salt soak, lowering lifetime costs.
• Manufactured and tested under ISO9001 processes with robust pressure testing.
• Designed to fit standard 20in x 4.5in whole-house filter housings used in three-stage systems.

Cons

• Not a multi-contaminant cartridge-primarily targets iron and manganese, so additional stages are required for sediment or chlorine removal.
• Regeneration requires time and access to salt water, which may be inconvenient for some users.

Specifications

Filter type	Reusable resin granule iron & manganese reducer
Micron rating	5 micron
Size	20in x 4.5in
Useful life	Approximately 6 months or 4,000 gallons
Reduction capability	Iron up to 3.0 ppm to ~0.01 ppm; manganese up to 1.0 ppm to ~0.01 ppm
Quality standards	Produced under ISO9001 with pressure and water hammer testing

Our Verdict

The PUREPLUS RFN20BB cartridge is a solid choice for whole-house iron and manganese reduction when used as part of a three-stage filtration system; its reusable resin and clear service life make it good value for homeowners with well water concerns. Those who need broad-spectrum contaminant removal or who cannot perform periodic regeneration should consider additional stages or a different cartridge.

Frequently Asked Questions

Can the resin be regenerated?
Yes. The inner resin granule filter can be soaked in salt water for about 12 hours to restore iron and manganese reduction performance.

How long does one cartridge last?
The cartridge is designed for about 6 months of use or up to 4,000 gallons, whichever comes first.

Will this fit my whole-house system?
It fits standard 20in x 4.5in whole-house filter housings and is intended for use in a 3-stage protection arrangement; verify housing compatibility before purchase.