Woder WD-G4-REP Advanced Filtration Cartridge (New WD-S-8K)

WQA-Certified Woder Advanced filters are certified by WQA to NSF/ANSI 42 for Chlorine taste, odor and NSF/ANSI 372 for lead free compliance as verified and substantiated by test data.

Removal Capabilities: Woder’s Advanced Filtration cartridge WD-G4-REP (Replaces the WD-S-8K / WD-S-8K-REP / WD-Gen3) removes 99.9% of lead, heavy metals, chlorine, chromium 6, mercury, volatile organic compounds, carcinogens, and other contaminants, turbidity, odor and bad tastes. (claims tested by CLB Labs and are not certified by WQA)

The WD-G4-REP cartridge, also known as WD-G4-L or WD-G4-2512TC, is a single stage replacement cartridge for:

Woder WD-G4-DC Water Filter.
Woder WD-G4-JG Water Filter.

The WD-G4-L is the second (last) stage replacement cartridge for the following dual stage systems:

Woder WD-D-FRM-G4-DC Water Filtration System.
Woder WD-D-FRM-G4-JG Water Filtration System.
Woder WD-D-HM-G4-DC Water Filtration System.
Woder WD-D-HM-G4-JG Water Filtration System.
Woder WD-D-20M-G4-DC Water Filtration System.
Woder WD-D-20M-G4-JG Water Filtration System.

Cartridge lifespan: 1 year under warranty.

Selective Filtration™
Our proprietary Selective Filtration™ technology removes 99.9% of contaminants while leaving in all essential minerals. Reverse Osmosis (RO) filters also remove 99.9% of contaminants, however, RO also remove ALL the minerals found in tap water – including minerals your body needs. RO systems can waste thousands of gallons of water annually while flushing out contaminants down the drain.

Gen4 Advanced Filtration Replacement Cartridge (WD-G4-REP)

The WD-G4-REP is our standard advanced filtration cartridge, the replacement most Woder customers order when it’s time to refresh their system. If you’re a returning customer, you may know this cartridge by its earlier name, WD-S-8K, from our Gen3 generation. It’s now built on Gen4 Advanced Selective Filtration media, and it fits the same housings that took the earlier cartridge, so upgrading doesn’t mean replacing your whole system.

From Gen3 to Gen4: What Changed

The move from Gen3 to Gen4 wasn’t a rebrand, it reflects real upgrades to the filtration media itself, with improved reduction across the same core contaminants: lead, chlorine, PFAS, and chromium-6, while still keeping beneficial minerals in your water. If you’ve been running the older cartridge and are wondering whether the new one is a meaningful step up, it is, and it drops into your existing housing without any hardware changes on your end.

This cartridge carries WQA Gold Seal certification, the same third-party verification standard across our Gen4 Advanced product line. That certification means an independent lab has confirmed the contaminant reduction claims rather than us simply stating them, which matters if you’re relying on this cartridge as your household’s primary filtration.

Certification and Replacement

Replacing it is straightforward: depending on your housing type, it’s either a push-to-connect swap or a quick unscrew-and-replace under the sink. Our install guides walk through both processes, and most people are back up and running in a matter of minutes. This filter is designed and packaged in the USA. It fits housings across both our Advanced Filtration (Inline) and Advanced Filtration (Under-Sink) lineups.

Frequently Asked Questions

Is this the same as the old WD-S-8K cartridge?

It’s the Gen4 successor to that cartridge, sized to fit the same housings while running on upgraded Selective Filtration media with improved contaminant reduction.

Which Woder systems is this cartridge compatible with?

It’s built for our standard Gen4 Advanced housings, both inline and under-sink, including systems originally set up with the earlier WD-S-8K Gen3 cartridge.

Is this cartridge WQA certified?

Yes, it carries WQA Gold Seal certification, confirming its contaminant reduction performance through independent third-party testing.

How often should I replace it?

Cartridge life depends on usage and water quality, and the product page lists expected capacity so you can plan replacements ahead of a noticeable flow-rate drop.