Calcium GAC Fluoride Reduction Filter Cartridge

Fluoride reaches tap water two ways: many cities add it, and it also occurs naturally from the erosion of mineral deposits. If you want less of it in the water your family drinks, the media inside the filter is what matters most.

This bone char fluoride filter cartridge is filled with Crystal Quest Calcium GAC: black granular bone char made by calcining cattle bones until only a mineral framework of hydroxyapatite and a carbon surface remain. That mineral framework is what captures fluoride.

At a glance

• Targets fluoride in municipal water, with capacity stated for each size
• Real bone char: 70 to 76% hydroxyapatite and 9 to 11% carbon, per Crystal Quest's media data sheet
• A natural mineral reaction locks fluoride into the media as fluorapatite
• Bonus adsorption: the carbon and mineral surfaces also adsorb some heavy metals, such as lead
• Four sizes, 0.5 to 6 GPM, for countertop, under-sink and whole house housings

What you are looking at

Each cartridge is a sealed shell packed with Calcium GAC granules, closed with polypropylene end caps and Buna-N gaskets. The label shows the flow direction, the part number for each size and the replacement steps. The granules themselves are black, like charcoal. Each end cap has 1-micron pads behind its openings.

How bone char removes fluoride

The chemistry: a swap inside the crystal

Hydroxyapatite holds hydroxide (OH) groups in its crystal structure. Fluoride carries the same charge and is almost the same size, so it can take the hydroxide's place. The result is fluorapatite, a stable, insoluble mineral that stays locked in the media instead of returning to your water. At higher fluoride levels, some fluoride also precipitates as calcium fluoride.

A carbon surface, too

Unlike aluminum oxide fluoride media, bone char also carries carbon. Calcium GAC has a total surface area of about 200 m²/g, about 50 m²/g of it carbon. Bone char has proven itself in purifying sugar syrups, and in your water its carbon surface adds adsorption of some dissolved organic and colored compounds.

Why pH and contact time matter

Bone char takes up the most fluoride in slightly acidic water, near pH 6, and works less efficiently as pH rises. Fluoride uptake is also gradual, so contact time matters: slower flow gives the media more time to work, which is why each size has its own rated flow.

What it reduces

Primary target (printed on the cartridge label): fluoride, specifically inorganic fluoride in municipal water.

Also adsorbed by bone char (a capability of the media, not a separate tested rating for this cartridge):

• Heavy metals such as lead, which Crystal Quest's media data sheet lists among bone char's strengths
• Some dissolved organic and colored compounds, through its carbon surface

Not designed to treat: bacteria and viruses, nitrate, hardness, or chlorine and chemical tastes as a dedicated stage. For those, Crystal Quest pairs it with a SMART Filter Cartridge and other stages.

Is it right for my water? It is built for inorganic fluoride in municipal water. If your fluoride is organic or comes from a well or another natural source, talk to a Crystal Quest specialist first. Capacity is rated at hardness below 100 ppm. Bone char is animal-derived; if you prefer a non-animal media, choose the Aluminum Oxide Fluoride Reduction Filter Cartridge.

Why Crystal Quest

• Our default fluoride media. Calcium GAC is the standard fluoride cartridge media across Crystal Quest's cartridge systems. The Aluminum Oxide Fluoride Reduction Filter Cartridge (activated alumina) is an interchangeable alternative for people who prefer it.
• A published media spec. Hydroxyapatite and carbon content, surface area, pore structure and hardness are listed in the Specifications tab, from Crystal Quest's own data sheet.
• Clear scope. We tell you the water it is built for and the conditions behind every capacity figure.
• 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

• Single specialty systems: the fluoride stage on its own
• Double specialty systems: after a SMART cartridge
• Triple specialty systems: last stage, after a carbon block and SMART

Only have one housing? The SMART + Calcium GAC Fluoride Reduction Cartridge combines both in one cartridge. Choose the size printed on your current cartridge or in your order history: 2-7/8" x 9-3/4" (CQE-RC-04126), 2-7/8" x 20" (CQE-RC-04127), 4-5/8" x 9-3/4" (CQE-RC-04128) or 4-5/8" x 20" (CQE-RC-04129).

Common questions

Calcium GAC fluoride cartridge specifications

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

Calcium GAC media (Crystal Quest data sheet)

*Capacity is an estimate only and is dependent on influent water contaminants and filter usage. Rated at hardness below 100 ppm.

*Cartridge color is subject to change without notice.

*Use only on water that is microbiologically safe. Run water 5 to 10 minutes before first use.