This cartridge (CT-5020-0640RD-F11) fits any Enpress PIONEER 8" x 40" cartridge tank - including our Pioneer Arsenic Removal System in both the standard bypass and metered tank versions. It does not fit Big Blue housings or standard 4.5" x 20" filter housings. If you're not sure what you have, text a photo of your tank to 443-277-2204 and we'll confirm before you order.

It's rated for 125,000 gallons of arsenic reduction (reducing 0.050 mg/L below the EPA's 0.010 mg/L limit, tested to NSF/ANSI 53 in the complete system). At a typical household's 200-300 gallons per day, that's roughly 12-20 months. The metered tank version counts your actual gallons and signals when replacement is near; with the bypass version, set a calendar schedule from your usage and test treated water annually.

Yes. That's the defining feature of ATOMUS F11 media. Most arsenic medias (including ion exchange resins) only remove arsenate (As V) effectively, and arsenite (As III) must first be converted with chlorine or aeration. ATOMUS F11's binary mixed metal formulation captures both forms simultaneously, which is why the Pioneer system needs no oxidizer, no air-injection valve, and no chemical feed. If your water test shows arsenite, this is the simplest path to compliant water.

Yes. Put the tank in bypass, press the red pressure-relief button, pull the snap ring, lift the cap, exchange the cartridge, reassemble, and flush for 10 minutes. Most homeowners finish in about 10 minutes the first time and 5 minutes every time after. We'll walk you through your first swap on the phone if you'd like.

In most jurisdictions, normal household trash. The arsenic bond in ATOMUS F11 is non-leachable - it passes the USEPA TCLP and California WET tests, which are the standards for landfill-safe waste. Some states have stricter local rules, so check your municipality or call us and we'll help you verify.

Because the cartridge IS the treatment. The PIONEER tank is a pressure vessel you buy once; the engineered media inside the cartridge is what actually captures arsenic, and ATOMUS F11 media is expensive to manufacture (binary mixed metal formulation, powder processing, NSF certification). You're replacing the entire treatment bed every swap - the equivalent of a full media change-out on a tank system, but without the labor.

We recommend it. Arsenic breakthrough is invisible - no taste, color, or smell - so you don't want your protection gap to be 'however long shipping takes.' Keep one sealed spare on the shelf (it stores for years in a cool dry place), swap when the meter signals or your schedule says, and reorder the spare.