Bleach in your coffee. A pool smell when the shower runs. Ice cubes that taste like the tap. On treated city water those complaints usually trace back to chlorine or chloramine, the two disinfectants utilities add before water reaches your home.
This GAC filter cartridge is built for exactly that job. Inside is a three-media blend of coconut shell granular activated carbon, catalytic carbon GAC and ERA 6500 redox media that reduces the taste and odor of chlorine and chloramine along with volatile organic compounds (VOCs). It comes in four sizes, rated from 0.5 to 6 GPM, that drop into standard 2.5 x 10, 2.5 x 20, 5 x 10 and 5 x 20 inch housings, including Crystal Quest countertop, under-sink and whole house systems.
At a glance
- Handles both city disinfectants: chlorine and the harder-to-treat chloramine, by taste and odor
- Three media, three jobs: coconut shell GAC for VOCs, catalytic carbon for chloramine, ERA 6500 to keep the cartridge cleaner
- Built-in post-filter: a spun polypropylene layer holds back loose carbon fines before water leaves the cartridge
- Four sizes, 0.5 to 6 GPM, for countertop, under-sink and whole house housings
- Long service life: typically 12 to 24 months, about 18 months for most homes
What you are looking at
The photos show the cartridge as it ships: a rigid polystyrene casing with polystyrene end caps, packed with loose carbon granules and ERA 6500 granules. A polypropylene expansion pad keeps the bed packed tight so water cannot channel around the media, a spun polypropylene post-filter sits at the outlet, and a Buna-N gasket on top seals against the housing cap. Cartridge color can change between production runs; the media inside does not. Each end cap has 1-micron pads behind its openings.
How a GAC filter cartridge works
Adsorption on a huge internal surface
Activated carbon is carbon that has been steam-activated at very high temperature until it is honeycombed with microscopic pores. That internal surface is enormous, and many organic chemicals, including the compounds behind chlorine taste and odor and many VOCs, cling to it as water flows past. That is adsorption. Coconut shell is a hard, dense starting material that produces a high share of the very small pores that suit drinking water.
Catalytic carbon for chloramine
Many utilities now disinfect with chloramine, a longer-lasting blend of chlorine and ammonia. Ordinary carbon breaks chloramine down slowly. Catalytic carbon has a modified surface that speeds up that reaction, which is why Crystal Quest adds it to this blend to reduce more of the chloramine taste and odor than plain GAC would.
ERA 6500 redox media
ERA 6500 is Crystal Quest's Eagle Redox Alloy: high purity copper-zinc granules that work by oxidation and reduction, a direct exchange of electrons with contaminants in the water. Against free chlorine it converts the chlorine to harmless chloride. In this blend it shares the chlorine load with the carbon and helps limit bacterial growth inside the cartridge between uses.
Why the post-filter and expansion pad matter
Loose granules can shed fine carbon dust, and a loose bed lets water find shortcuts. The expansion pad keeps the granules packed so every drop passes through media, and the spun polypropylene post-filter catches fines at the outlet, so the water leaving the cartridge is clean as well as better tasting.
Contact time matters
The longer water stays in contact with carbon, the more the carbon can adsorb. Each size carries its own rated flow, from 0.5 GPM for the 2-7/8" x 9-3/4" to 6 GPM for the 4-5/8" x 20". Stay within the rated flow of your size and the blend has the contact time it was designed around.
What it reduces
Primary targets:
- Chlorine taste and odor
- Chloramine taste and odor
- Volatile organic compounds (VOCs)
Also reduced by activated carbon, where present (a capability of the media, not a separate tested rating for this cartridge):
- Some pesticides and herbicides
- Some disinfection byproducts, such as trihalomethanes (THMs)
- Other organic taste and odor compounds
Not designed to treat: bacteria and viruses in the water (ERA 6500 protects the cartridge, it does not disinfect your water), hardness minerals, fluoride, nitrate, total dissolved solids, or lead and other heavy metals. For those, Crystal Quest has dedicated stages such as the Lead Filter Cartridge, the Ultrafiltration (UF) Water Filter Membrane and reverse osmosis.
Why Crystal Quest
- A real blend, not a single carbon. Coconut shell GAC, catalytic carbon and ERA 6500 each do a different job, so one cartridge covers chlorine, chloramine and VOCs.
- Sized by real measurements. Every option is listed by actual cartridge diameter and length, with its own rated flow.
- Over 1,000,000 people served since 1994. Crystal Quest builds under ISO 9001 quality management and has made water filtration in the USA for over 30 years.
- Lifetime support. Call, email or chat with our water filtration team whenever you have a question.
Where it fits
- Systems that specify a GAC stage: Crystal Quest countertop, under-sink and whole house cartridge systems built around loose granular carbon
- Chloraminated city water: the catalytic carbon in this blend is there for chloramine taste and odor
- Keep the type your system specifies: this is a different cartridge from the Coconut Based 5-Micron Carbon Block Filter Cartridge, and the two are not interchangeable stages
Pick the size printed on your current cartridge or in your order history: 2-7/8" x 9-3/4" (CQE-RC-04103), 2-7/8" x 20" (CQE-RC-04105), 4-5/8" x 9-3/4" (CQE-RC-04104) or 4-5/8" x 20" (CQE-RC-04106).
Common questions
How is a GAC filter cartridge different from a carbon block?
This cartridge holds loose granules of coconut shell and catalytic carbon with ERA 6500 redox media, finished by a spun polypropylene post-filter. A carbon block is one solid block of carbon with a 5-micron particle rating. Keep the type your system specifies.
Does it remove chlorine and chloramine?
It reduces the taste and odor of both. The coconut shell GAC and ERA 6500 handle chlorine, and the catalytic carbon is in the blend to reduce more of the chloramine taste and odor than plain carbon can.
What does the ERA 6500 do?
ERA 6500 is Crystal Quest's Eagle Redox Alloy, high purity copper-zinc granules that react with chlorine through oxidation and reduction. In this blend it supports the carbon on chlorine and helps limit bacterial growth inside the cartridge.
Is coconut shell carbon better than other carbon?
Coconut shell makes a hard, dense activated carbon with a high share of very small pores, the size range that suits taste, odor and VOC adsorption in drinking water. That is why it is the base carbon in this blend.
Will it remove fluoride, lead or hardness?
No. Activated carbon does not remove fluoride, nitrate or hardness minerals, and this blend is not a heavy metal stage. Crystal Quest offers dedicated fluoride, lead and softening solutions.
How often should I replace a GAC filter?
Typically 12 to 24 months, about 18 months for most homes. Replace sooner if taste, odor, flow or pressure changes. Actual life depends on feed water quality, system configuration and usage.
Which size fits my housing?
Use the actual diameter and length on your current cartridge: 2-7/8" x 9-3/4", 2-7/8" x 20", 4-5/8" x 9-3/4" or 4-5/8" x 20". These fit 2.5" x 10", 2.5" x 20", 5" x 10" Big Blue and 5" x 20" Big Blue housings.
GAC cartridge specifications
Published ratings apply to the selected cartridge. Sizes are actual cartridge diameter x length.
| ITEM NUMBER | SIZE | FITS HOUSING | FLOW RATE | TYPICAL REPLACEMENT |
| CQE-RC-04103 | 2-7/8” x 9-3/4” | 2.5" x 10" | .5 gpm (1.9 lpm) | 12 to 24 months* |
| CQE-RC-04105 | 2-7/8” x 20” | 2.5" x 20" | 2.5 gpm (9.4 lpm) | 12 to 24 months* |
| CQE-RC-04104 | 4-5/8” x 9-3/4” | 5" x 10" Big Blue | 3 gpm (11.4 lpm) | 12 to 24 months* |
| CQE-RC-04106 | 4-5/8” x 20” | 5" x 20" Big Blue | 6 gpm (22.7 lpm) | 12 to 24 months* |
Media and filtration
| Media | Premium Coconut Shell GAC, Catalytic Coconut Shell GAC and Eagle Redox Alloy 6500 |
| Media form | Loose granular bed with polypropylene expansion pad |
| Post-filter | Spun polypropylene |
| End pads | 1-micron pads behind the end-cap openings |
| Reduces | Chlorine and chloramine taste and odor, VOCs |
| Not designed for | Hardness, fluoride, nitrate, TDS, heavy metals, microbiologically unsafe water |
Operating conditions
| Water temperature | 40°F to 145°F (4.4°C to 62.8°C) |
| Water quality | Use only on microbiologically safe water |
| Before first use | Flush as your system manual directs |
Construction Materials
- Fiber Media: Coconut Shell GAC, Catalytic Carbon GAC, Eagle Redox Alloy 6500
- End Caps: Polystyrene
- Post-Filter: Spun Polypropylene
- Outer Casing: Polystyrene
- Expansion Pad: Polypropylene
- Gasket: Buna-N (top)
- Temperature Rating: 40°F to 145°F (4.4°C to 62.8°C)
*Typically 12 to 24 months, about 18 months for most homes. Replace sooner if taste, odor, flow or pressure changes. Actual life depends on feed water quality, system configuration and usage.
*Cartridge color is subject to change without notice