Pentek RFC-BB Radial Flow Carbon Filter - 10" Jumbo 4.5", High Flow GAC NZ

A high-flow granular activated carbon cartridge for Jumbo (Big Blue) 10" x 4.5" housings — low pressure drop with significantly reduced carbon fines.

The Pentek RFC-BB is a radial flow GAC cartridge designed for point-of-entry and high-flow whole-house applications. The unique radial flow design passes water through a bed of granular activated carbon from the outside in, reducing chlorine, taste, and odour at high flow rates while keeping pressure drop low. The 70-micron porous polyethylene outer shell contains the carbon bed and significantly reduces the release of carbon fines into the filtered water — a common issue with standard GAC cartridges.

NSF/ANSI Standard 42 certified for material requirements only. Chlorine reduction figures are manufacturer-stated.

Key specs at a glance

• Filter media: granular activated carbon (GAC)
• Size: 4.5" x 9.75" (114mm x 248mm) — Jumbo / Big Blue 10"
• Chlorine reduction capacity: >189,270L @ 7.6 L/min (manufacturer-stated)
• Initial pressure drop: 0.06 bar (0.90 psi) @ 7.6 L/min
• Temperature range: 4.4–51.7°C
• NSF/ANSI 42 certified — material requirements only
• Suits point-of-entry and high-flow whole-house installations

How it works

Standard GAC cartridges can release carbon fines — fine carbon particles — into filtered water, particularly when flow rate varies. The RFC-BB uses a radial flow design: water enters through the 70-micron porous polyethylene outer shell and flows radially inward through the carbon bed to the polypropylene core. This construction contains the carbon bed and substantially reduces fines in the filtered water while keeping pressure drop low — making it well suited to high-flow whole-house applications where consistent water quality matters.

Full specifications

What's in the box

• 1 x Pentek RFC-BB radial flow carbon cartridge

Frequently asked questions

What is a radial flow carbon cartridge and how is it different from a carbon block?

A radial flow cartridge uses loose granular activated carbon packed between an outer shell and an inner core. Water flows radially inward through the carbon bed. Unlike a carbon block, the GAC design offers very low pressure drop and high flow capacity — better suited to main water line and whole-house applications where flow rate is more important than fine particulate filtration.

Why does the radial flow design reduce carbon fines?

The RFC-BB's 70-micron porous polyethylene outer shell contains the carbon bed and acts as a barrier that substantially reduces the release of carbon fines into the filtered water — a common issue with standard loose GAC cartridges.

What does NSF/ANSI 42 certification mean for this cartridge?

The NSF/ANSI 42 certification on the RFC-BB covers material requirements only — it confirms the materials in contact with drinking water are safe. It does not certify the chlorine reduction performance claim. That figure is manufacturer-stated based on internal testing.

Will it fit my existing housing?

Yes, if your housing is a standard Jumbo (Big Blue) 10" x 4.5" size. If you're unsure, check your housing's internal diameter before ordering.

How often should I replace it?

Replacement depends on water quality and usage. The manufacturer states a chlorine reduction capacity of over 189,270 litres at 7.6 L/min. Replace when chlorine taste or odour returns, or when flow drops noticeably.

Can I use this on tank or bore water?

Yes, as a chlorine, taste, and odour reduction stage on disinfected supplies. This cartridge does not filter fine sediment — pair with a sediment pre-filter on tank or bore supplies.