Weddell Duo Shower Filter (WD-100)

Checked against its certification listings: what they cover, what the maker claims, and what it costs over five years.

Shower

Listings checked Oct. 16, 2026

Certified to

NSF/ANSI 177NSF listingchecked Oct. 16, 2026

Certified for: Chlorine

Maker’s list price

$90

as of Oct. 16, 2026

Each replacement, at list price

Replacement cartridge set (WD-100F, sediment and carbon): $30

Five years, 40 gallons of showers a day

$420

0.6¢ per gallon

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Price on Amazon The maker’s page

List price from the maker’s site, checked Oct. 16, 2026. Prices change; the maker’s page is the final word.

What the listings say

Standard	Certifier	Claims	Listing
NSF/ANSI 177	NSF	Free Available Chlorine Reduction	Read the listing checked Oct. 16, 2026

Certified for, and claimed

Certified, by a listing

Chlorine

Claimed by the maker only

PFAS
particulates

Certification claims we could not find on a listing

Weddell says the Duo is "NSF certified and verified to reduce harmful PFAS and particulates", citing 2023 tests by an IAPMO lab against NSF/ANSI 53 and NSF/ANSI 42. NSF lists it under NSF/ANSI 177 for free available chlorine only, and no listing for PFAS or particulates was found at NSF, WQA or IAPMO on Oct. 16, 2026.

What it costs over five years

40 gallons of showers a day, EPA WaterSense’s figure for the average family, all through this one shower. Installation not included.

Item	Replaced	Count	Amount
System, with first media	—	1	$90
Replacement cartridge set (WD-100F, sediment and carbon)	Every 5 monthsmonth rating	11	$330

Five-year total$420

Per gallon0.6¢

Run it for your household

Worth knowing

NSF lists the WD-100 in black, white and pink (WD-100BL, WD-100WH, WD-100PN), which Weddell sells as the original Duo. A redesigned Duo, also $89.99, takes only redesigned cartridges, which were out of stock on Oct. 16, 2026. Weddell says to change the cartridges every 5 to 6 months or at their rated capacity, which its specifications give as 10,000 gallons, the figure NSF lists; 5 months is recorded, the first limit reached. Prices are the $89.99 and $29.99 regular prices; Weddell showed $79.99 and $24.99.

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