Companion Undersink Replacement Filter Pack

• Complete replacement pack:
  Includes the filters required for your
  selected Companion system configuration.
• Complementary filtration:
  Combines carbon block, electropositive
  nanofiber, and advanced carbon
  filtration technologies.
• Contaminant reduction:
  Designed to address chlorine,
  fine particulates, certain microbial
  contaminants, and other unwanted substances.
• Improved taste and odor:
  Carbon filtration helps reduce chlorine
  and substances that affect drinking
  water’s taste and smell.
• Flexible configurations:
  Available for three-stage systems
  and four-stage systems with additional
  carbon or dedicated nitrate filtration.
• Mineral preservation:
  Designed to retain naturally occurring
  dissolved minerals.
• Convenient maintenance:
  Recommended filter replacement every
  6–12 months, depending on household
  size, water quality, and usage.

Select the configuration that matches
your existing Companion Undersink system
using the product options above.

• 3-Stage System:
  Standard Companion Undersink configuration.
• 4-Stage with Additional Carbon:
  Companion system with an additional
  carbon filtration stage.
• 4-Stage with Nitrate Filter:
  Companion system with a dedicated
  nitrate reduction cartridge.

If you’re uncertain which configuration
you have, contact our team with a photo
of your system. We’re happy to help
identify the correct replacement pack.

Your replacement pack includes the
filtration cartridges needed for
the configuration selected above.

Stage 1 — Carbon Block Filtration

Premium carbon block filtration
designed to reduce chlorine and
improve drinking water’s taste
and odor.

Stage 2 — Electropositive Nanofiber Filtration

Advanced electropositive nanofiber
technology designed to capture
bacteria, viruses, cysts, and
ultrafine particles while maintaining
strong water flow.

Stage 3 — Advanced Carbon Filtration

Advanced carbon filtration provides
additional chemical contaminant
reduction and final water quality
refinement.

Stage 4 — Additional Filtration (Where Applicable)

Four-stage configurations include
either an additional carbon filter
or a dedicated nitrate reduction
cartridge, depending on the
option selected.

Together, these complementary
filtration stages help maintain
clean, great-tasting drinking
water while preserving naturally
occurring dissolved minerals.

Companion replacement packs combine
complementary filtration technologies
selected for contaminant reduction,
strong water flow, and reliable
household performance.

The electropositive nanofiber stage
uses specialized filtration technology
designed to capture bacteria, viruses,
cysts, and extremely fine particles
while maintaining low pressure drop.

The carbon filtration stages provide
chlorine reduction, improved taste
and odor, and additional chemical
contaminant reduction.

Manufacturer technical documentation
provides information about filtration
capabilities under defined conditions.
Actual performance and filter life
can vary depending on incoming water
quality, contaminant concentrations,
flow rate, and household usage.

Explore the available technical
documentation below.

Nanofiber Performance Data

Carbon Block Performance Data

For optimal performance, we recommend
replacing your Companion Undersink
filters approximately every
6–12 months.

Replacement frequency depends on
household size, water consumption,
incoming water quality, and
overall system usage.

Larger households or homes with
higher water consumption will
often benefit from replacement
closer to every 6–8 months,
while smaller households with
lighter usage may be able to
go longer.

These recommendations reflect
our experience supporting
Greenfield filtration systems
in real-world household conditions.

Replacement and sanitization
guides are available to help
you maintain your Companion
Undersink system.

Replacement Guide (PDF)

Sanitization Guide (PDF)

Questions about replacement,
compatibility, or maintenance?
Our team is happy to help.