Arsenic Removal Filter Cartridge

Arsenic has no taste, no odor and no color. Water can look perfect and still carry it, and the only way to know is a water test. Arsenic is highly toxic and has been classified by the EPA as a carcinogen, and the drinking water limit is just 10 parts per billion.

The Crystal Quest Arsenic Removal Filter Cartridge is a dedicated arsenic stage for well water and other sources where a test has found arsenic. It is filled with Eagle Arsenic Oxide, Crystal Quest's iron hydroxide arsenic media, designed to capture both forms of arsenic found in water, arsenic V (arsenate) and arsenic III (arsenite), in a standard drop-in cartridge.

At a glance

• Targets arsenic, both arsenic V and arsenic III
• Capacity with conditions: 1,000 to 60,000 gallons by size, rated at under 100 ppm hardness
• No electricity, drain line or chemicals: it works in a standard filter housing
• Four sizes, 0.5 to 6 GPM, for countertop, under-sink and whole house housings
• A dedicated stage, or pair it with SMART for broad filtration

What you are looking at

Each cartridge holds a bed of arsenic-selective media in polyolefin inner and outer wraps and polyethylene netting, closed with polypropylene end caps and sealed with Buna-N gaskets. Water flows through the media bed, where the arsenic stays behind. Each end cap has 1-micron pads behind its openings.

How an arsenic filter cartridge works

Where arsenic comes from

Arsenic does not dissolve easily, so when it turns up in a water supply it usually traces back to natural mineral deposits, mining and metal processing, or runoff from land where arsenic compounds were once used as pesticides. Private wells carry the highest risk because no utility tests them for you.

Two forms, two behaviors

Arsenic V (arsenate) is the oxidized form. At normal water pH it carries a negative charge, so selective media grab it quickly and hold it tightly. Arsenic III (arsenite) is common in low-oxygen groundwater. At normal pH it carries no charge, so it is slower to capture. Media designed for both forms still work best when most of the arsenic is arsenic V, which is why a well with mostly arsenic III may benefit from an oxidation step ahead of the cartridge.

What competes for the media

Arsenic and phosphate are chemical look-alikes and easily substitute for one another, so phosphate in the water competes for the same sites. Other anions, such as sulfate, compete too. The more of them your water carries, the sooner the media fills. That is why the capacity table states its condition, and why your full water test matters as much as the arsenic number.

Why capacity has conditions

Every microgram of arsenic the cartridge captures uses part of its capacity. Crystal Quest rates each size at under 100 ppm hardness instead of quoting a bare gallon number. Higher arsenic, phosphate or flow uses capacity faster.

What it reduces

Primary target: arsenic, both arsenic V (arsenate) and arsenic III (arsenite). Capacity is rated for each size in the Specifications tab.

Not designed to treat: bacteria and viruses, nitrate, fluoride, hardness, iron, or chlorine and chemical tastes. Use it only on microbiologically safe water.

Is it right for my water?

Start with a lab test for total arsenic, and ask the lab to report arsenic III and arsenic V separately if it can. Add phosphate, sulfate, iron and pH to the same test. With those numbers, Crystal Quest can tell you which size fits your arsenic load and whether an oxidation stage ahead of the cartridge will help.

If you want arsenic reduction and broad chemical filtration from one stage, the Arsenic Removal + SMART Filter Cartridge combines arsenic-selective media with carbon and redox media. For a whole home, ask us about an arsenic tank system.

Why Crystal Quest

• Built for both forms of arsenic, with the chemistry explained so you know what to test for.
• Numbers you can plan with. Every size carries a gallon rating and the hardness condition behind it.
• A complete arsenic lineup: this dedicated cartridge, the SMART combination and whole house arsenic systems.
• Over 1,000,000 people served since 1994. Crystal Quest builds under ISO 9001 quality management, has made water filtration in the USA for over 30 years and offers lifetime support by phone, email or chat.

Where it fits

• Countertop and under-sink systems that take the 2-7/8" x 9-3/4" size, for arsenic-reduced drinking and cooking water.
• Whole house cartridge systems with slim 20" or Big Blue housings.

Choose the size printed on your current cartridge or in your order history: 2-7/8" x 9-3/4" (CQE-RC-04008), 2-7/8" x 20" (CQE-RC-04021), 4-5/8" x 9-3/4" (CQE-RC-04067) or 4-5/8" x 20" (CQE-RC-04070).

Common questions

Arsenic filter cartridge specifications

Published ratings apply to the selected cartridge and listed conditions. Capacity is an estimate that depends on incoming water contaminants and usage.

Media and treatment

*Capacity is an estimate at under 100 ppm hardness. Actual life depends on incoming water contaminants and usage.