Coconut Based 5-Micron Carbon Block Filter Cartridge
That swimming-pool smell when you fill a glass. Coffee that tastes a little off. A chemical note in the shower. On chlorinated city water, that is usually chlorine, and activated carbon is the classic fix.
This replacement carbon block water filter is one solid block of acid-washed coconut shell activated carbon, rated at 5 microns. It reduces chlorine taste and odor, volatile organic compounds (VOCs) and fine sediment, so the water from your Crystal Quest countertop, under-sink, reverse osmosis or whole house system tastes clean again.
At a glance
- Better-tasting water: reduces chlorine taste and odor and VOCs, the targets printed on every cartridge label
- Two jobs in one stage: carbon adsorption plus mechanical filtration of particles down to 5 microns
- Acid-washed coconut shell carbon formed into a solid block with a low pressure drop, so flow stays strong
- Four sizes, 0.5 to 6 GPM, for countertop, under-sink, RO 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 dark carbon block inside a polyolefin wrap and polypropylene netting, closed with polypropylene end caps and a Buna-N gasket on top that seals against the housing cap. The label carries the part numbers, the pressure range and the replacement steps, so the next change is easy.
How a carbon block filter works
Adsorption on a huge internal surface
Activated carbon is carbon that has been treated with steam at very high temperature until it is full of tiny pores. That internal surface is enormous. As water passes through, many organic chemicals and the compounds behind chlorine taste and odor are attracted to the carbon and held on its surface. Chemists call this adsorption.
Why coconut shell, and why acid-washed
Crystal Quest specifies coconut shell carbon for this block and has it acid-washed, an extra processing step used to enhance how well activated carbon removes contaminants. The result is a clean, dense carbon made for drinking water.
Why a solid block
Loose granular carbon (GAC) adsorbs, but it does not strain. Because this carbon is one solid block, it does both: it adsorbs chemicals and it catches particles down to its 5-micron rating. You get carbon treatment and fine sediment filtration in a single housing.
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". Taste and odor compounds take relatively little carbon to handle, which is a big reason a carbon block keeps water tasting clean for many months.
What it reduces
Primary targets (printed on the cartridge label):
- Chlorine taste and odor
- Volatile organic compounds (VOCs)
- Sediment and fine particles down to 5 microns
Also reduced by activated carbon, where present (a capability of the media, not a separate tested rating for this cartridge):
- Some pesticides and herbicides, such as atrazine
- Some disinfection byproducts, such as trihalomethanes (THMs)
- Other organic taste and odor compounds
Chloramine: activated carbon can reduce it, but a standard carbon block is less effective on chloramine than catalytic carbon. If your city uses chloramine, pair this block with a SMART Filter Cartridge, whose blend includes catalytic carbon.
Not designed to treat: bacteria and viruses, 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, SMART cartridges and reverse osmosis.
Why Crystal Quest
- Specified for our own systems. This is the carbon block stage in Crystal Quest double and triple cartridge systems, Thunder under-sink RO systems and whole house RO pre-filtration, so a replacement matches what your system was designed around.
- Sized by real measurements. Every option is listed by actual cartridge diameter and length, not a loose nominal size.
- 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
- Double cartridge systems: first stage, ahead of SMART
- Triple cartridge systems: last stage, after sediment and SMART
- Specialty triple systems: first stage, ahead of SMART and the specialty cartridge
- Thunder under-sink RO: third pre-filter, after UF and SMART, protecting the membrane
- Whole house RO with three pre-filter housings: after sediment and SMART
- Metal Removal triple cartridge systems: last stage, after the iron cartridge and SMART
Pick the size printed on your current cartridge or in your order history: 2-7/8" x 9-3/4" (CQE-RC-04000), 2-7/8" x 20" (CQE-RC-04014), 4-5/8" x 9-3/4" (CQE-RC-04035) or 4-5/8" x 20" (CQE-RC-04036).
Common questions
How is a carbon block different from a GAC cartridge?
A carbon block is one solid block of carbon with a 5-micron rating, so it also filters fine particles. Crystal Quest's GAC cartridge holds loose granules of coconut shell and catalytic carbon blended with ERA 6500 redox media. Keep the type your system specifies.
Does a carbon block filter remove chlorine and chloramine?
It reduces chlorine taste and odor, its primary job. Activated carbon can also reduce chloramine, but a standard carbon block is less effective on it than catalytic carbon, so on chloraminated city water pair it with a SMART cartridge.
Will it remove fluoride, lead or hardness?
No. Activated carbon does not remove fluoride, nitrate or hardness minerals, and a standard carbon block is not a heavy metal stage. Crystal Quest offers fluoride, lead and softening solutions for those jobs.
Which size carbon block 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. Each size has its own flow rate, from 0.5 to 6 GPM.
How often should I replace a carbon block 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.
Why is the first water gray after a change?
A new carbon block can release fine carbon particles at first. Run the water for 5 to 10 minutes before first use, as the cartridge label directs, and it clears.
Where does the carbon block go in a multi-cartridge system?
In Crystal Quest's double systems it comes first, ahead of SMART. In triple systems it is the last stage, after sediment and SMART.
Carbon block specifications
Published ratings apply to the selected cartridge. Sizes are actual cartridge diameter x length.
| SKU | SIZE | FITS HOUSING | FLOW RATE | TYPICAL REPLACEMENT |
| CQE-RC-04000 | 2-7/8” x 9-3/4” | 2.5" x 10" | .5 gpm (1.9 lpm) | 12 to 24 months* |
| CQE-RC-04014 | 2-7/8” x 20” | 2.5" x 20" | 2.5 gpm (9.4 lpm) | 12 to 24 months* |
| CQE-RC-04035 | 4-5/8” x 9-3/4” | 5" x 10" Big Blue | 3 gpm (11.4 lpm) | 12 to 24 months* |
| CQE-RC-04036 | 4-5/8” x 20” | 5" x 20" Big Blue | 6 gpm (22.7 lpm) | 12 to 24 months* |
Media and filtration
| Media | Acid-washed coconut shell activated carbon, solid carbon block |
| Micron rating | 5 micron |
| Reduces (cartridge label) | Chlorine taste and odor, VOCs, sediment |
| Not designed for | Hardness, fluoride, nitrate, TDS, heavy metals, microbiologically unsafe water |
Operating conditions
| Pressure range | 30 to 60 psi (2.1 to 4.1 bar) |
| Water temperature | Cold water only, 40°F (4.4°C) minimum |
| Water quality | Use only on microbiologically safe water |
| Before first use | Run water 5 to 10 minutes |
Construction Materials
- Fiber Media: Acid-Washed Coconut Shell Granular Activated Carbon
- End Caps: Polypropylene
- Inner/Outer Casing: Polyolefin
- Netting: Polypropylene
- Gasket: Buna-N (top)
*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.
A little checking. A better fit.
Compare the number on your current filter with the compatibility details above.
Confirm dimensions, connections and equipment model. A similar appearance does not confirm fit.
Check the selected size, pack quantity and included items before adding to your cart.