Vertex FK-100 RO System Annual Filter Kit Standard GAC

PT-40 & PT-504 Reverse Osmosis Water Filtration Systems

SKU: FK-100 & FK-100-CAL

Vertex FK - 100 - Reverse Osmosis System Annual Filter Kit - Pure n Natural Systems

Vertex FK-100 RO System Annual Filter Kit Standard GAC

PT-40 & PT-504 Reverse Osmosis Water Filtration Systems

SKU: FK-100 & FK-100-CAL

$76.95
Stage 4 Filter:

Stage 4 Filter

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About this product

Replacement Filter Kit for PT-4.0 and PT-504 Vertex PureWaterMachine Reverse Osmosis System

The FK-100 Annual Filter Kit is designed to provide complete, once-per-year maintenance for PT-40 and PT-504 reverse osmosis water filtration systems. This kit replaces the primary pre-filtration and polishing stages that protect the RO membrane and maintain clean, great-tasting drinking water.

By replacing these filters annually, the FK-100 helps reduce sediment, chlorine, taste and odor issues, and other common contaminants before they reach the RO membrane. This protects system performance, supports consistent water quality, and helps extend the life of downstream filtration components.

The FK-100 is intended for routine preventative maintenance and is recommended for PT-40 and PT-504 RO systems operating in residential, office, and light commercial environments.

The FK-100 (Standard GAC) is the standard annual filter kit that restores pre-filtration and final carbon polishing in Vertex PT-40 and PT-504 RO systems, while the FK-100-CAL (GAC/Calcite) includes a calcite-enhanced post filter to remineralize RO water and help balance pH after filtration. 

Replace all filters annually.

(RO Membrane sold separately)

For use in the following models:

Best for
  • Annual maintenance of Vertex PT-40 and PT-504 reverse osmosis systems
  • Protecting the RO membrane from sediment and chlorine exposure
  • Maintaining consistent taste, clarity, and odor reduction
  • Homes, offices, and facilities using PT-40 or PT-504 systems year-round
  • Users following manufacturer-recommended annual service intervals

Specifications

What's in the box

FK-100 Filter kit includes:

  • (1) Sediment Filter - 5-micron poly-spun cartridge - The 5-micron poly-spun filter takes out suspended solids such as dirt, rust, sand, and pipe scale.
  • (1) Activated Carbon Block Filter - 10-micron - Activated carbon block filter removes chlorine, bad tastes, and odors.
  • (1) Granular Activated Carbon post-filter - When the faucet is opened, clean water from the storage tank flows through the final polishing filter of activated carbon and into the faucet for your use. This special faucet is installed on your sink to dispense safe, good tasting drinking water which is especially good for coffee, tea, and drinks.
  • (1) - Filter Wrench
  • (2) - "O" Rings
  • Instruction Manual

FK-100-CAL Filter kit includes:

  • (1) Sediment Filter -  5-micron poly-spun cartridge - The 5-micron poly-spun filter takes out suspended solids such as dirt, rust, sand, and pipe scale.
  • (1) Activated Carbon Block Filter - 10-micron - Activated carbon block filter removes chlorine, bad tastes, and odors.
  • *(1) GAC/Calcite Post Filter - *Optional Stage 4 GAC/Calcite filter - Brings the water pH back up to 7. Typically, reverse osmosis purification removes minerals which subsequently causes the pH level to drop. This optional post filter will replace the mineral and will raise the pH to (around) 7
  • (1) - Filter Wrench
  • (2) - "O" Rings
  • Instruction Manual

Installation tips
  • Shut Off Water Supply: Turn off the feed water to the system.
  • Relieve Pressure: Open the faucet to release system pressure.
  • Remove Used Filters: Unscrew each filter housing and remove the old cartridges.
  • Install New Filters: Insert the replacement filters in the correct order and orientation.
  • Check O-Rings: Inspect and lubricate O-rings if needed before reassembly.
  • Restore Water Supply: Slowly turn the water back on and check for leaks.
  • Flush the System: Flush the system for several minutes to clear air and carbon fines before use.
  • No special tools are required beyond a standard filter housing wrench, if needed.

Frequently asked questions

What is the FK-100 annual filter kit used for?
It is used for routine annual replacement of the sediment, carbon, and post-carbon filters in Vertex PT-40 and PT-504 reverse osmosis systems to maintain water quality and system performance.

Which systems is the FK-100 compatible with?
The FK-100 is compatible with PT-40 and PT-504 reverse osmosis water filtration systems that follow the standard filter configuration.

How often should this filter kit be replaced?
The filters in the FK-100 kit are typically replaced once per year, depending on water quality and usage.

Does this kit include the RO membrane?
No. The FK-100 kit does not include the RO membrane. The RO membrane is replaced separately based on performance and water conditions.

What is the difference between the FK-100 and the FK-100-CAL?
The difference is the post filter (Stage 4). The FK-100 includes a standard GAC (granular activated carbon) post filter for final taste and odor polishing. The FK-100-CAL includes a GAC/Calcite post filter option that adds calcite to help bring RO water pH back up (around 7) by reintroducing minerals after reverse osmosis.
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