Description
Coconut Shell Big Blue Carbon Block Filter for Whole House Chlorine, Taste, and Odor Reduction
Overview
The Franklin FWCB Big Blue is a 4.5" OD carbon block filter cartridge manufactured from 100% coconut shell activated carbon. It reduces dissolved chlorine, taste, and odor in whole house, commercial, and industrial water systems. Available in 10" and 20" Big Blue lengths, with 0.5 and 5 micron ratings. Chlorine reduction capacity ranges from 60,000 to 150,000 gallons depending on size and micron. NSF 42 and NSF 61 certified for material safety requirements.
Specifications
| Specification | Detail |
|---|---|
| Series | FWCB (Big Blue) |
| Filter Type | Carbon block (adsorption filter) |
| Carbon Media | 100% Coconut Shell Activated Carbon |
| Sizes | 4.5" x 10" and 4.5" x 20" (Big Blue) |
| Micron Ratings | 0.5 and 5 |
| End Caps | Polypropylene |
| Wrap / Netting | Polypropylene |
| Gasket | Natural rubber |
| Operating Temperature | 4-50°C (40-120°F) |
| Max Operating Pressure | 10 Bar (150 psi) |
| Nominal ΔP for Replacement | 1.5 Bar (22 psi) |
| Certifications | NSF 42, NSF 61 (material requirements) |
| Housing Compatibility | Standard 4.5" OD Big Blue housings |
| Box Qty | 12 (10" BB) / 6 (20" BB) |
| Box Dimensions | 26 x 40 x 55 cm (10.2 x 15.8 x 21.7 in) |
| Box Weight | 14.0 kg / 30.6 lbs (10" BB) | 14.6 kg / 32.2 lbs (20" BB) |
Chlorine Reduction Capacity by Model
| Part # | Size | Micron | Chlorine Capacity | Initial ΔP | Box Qty |
|---|---|---|---|---|---|
| FWCB10B05 | 4.5" x 10" | 5 | >60,000 gal @ 3 GPM | 3 psid @ 3 GPM | 12 |
| FWCB10BP5 | 4.5" x 10" | 0.5 | >70,000 gal @ 3 GPM | 4.5 psid @ 3 GPM | 12 |
| FWCB20B05 | 4.5" x 20" | 5 | >120,000 gal @ 4 GPM | 4 psid @ 4 GPM | 6 |
| FWCB20BP5 | 4.5" x 20" | 0.5 | >150,000 gal @ 4 GPM | 5 psid @ 4 GPM | 6 |
Standard 2.5" vs Big Blue 4.5" Carbon Block
Cleanflow carries the FWCB carbon block in both standard 2.5" OD and Big Blue 4.5" OD formats. The Big Blue version provides dramatically higher chlorine capacity and flow rates:
| FWCB 2.5" x 10" | FWCB 4.5" x 10" (Big Blue) | |
|---|---|---|
| 5µ chlorine capacity | >17,000 gal @ 1 GPM | >60,000 gal @ 3 GPM |
| 0.5µ chlorine capacity | >20,000 gal @ 1 GPM | >70,000 gal @ 3 GPM |
| Rated test flow | 1 GPM | 3 GPM |
| Best for | Under-sink, POU, countertop | Whole house, commercial, high-throughput |
The Big Blue format handles 3x the flow rate and 3-4x the chlorine capacity of the standard 2.5" cartridge. For whole house systems, commercial installations, or any application above 1 GPM, the Big Blue is the right format.
Key Features
- 100% coconut shell activated carbon provides higher chlorine adsorption capacity and fewer carbon fines than coal-based carbon, with high sediment-holding capability.
- Carbon block construction eliminates channeling by forcing water through the full carbon matrix, providing consistent chlorine reduction across the cartridge's rated life.
- Big Blue 4.5" OD format handles flow rates from 3 to 4 GPM with chlorine capacity up to 150,000 gallons, supporting whole house and commercial systems that standard 2.5" cartridges cannot serve.
- NSF 42 and NSF 61 certified by NSF International for material safety requirements.
Applications
- Whole house chlorine, taste, and odor reduction
- Pre-filtration and post-filtration for reverse osmosis systems
- Commercial and industrial water treatment
- Food and beverage processing
- Potable and process water purification
- Residential POE/POU filtration
Cross-Reference: Waterite CBC to Franklin FWCB (Big Blue)
Franklin Water Treatment Canada now produces the former Waterite CBC carbon block line. The FWCB Big Blue cartridges replace the legacy Excelpure CBC Big Blue series with identical performance and specifications.
| Old Waterite/Excelpure Part | Franklin Replacement | Size | Micron |
|---|---|---|---|
| CBC10B05 / CBC10B05NX | FWCB10B05 | 4.5" x 10" | 5 |
| CBC20B05NX | FWCB20B05 | 4.5" x 20" | 5 |
If your system previously used a Waterite or Excelpure CBC Big Blue carbon block, order the corresponding Franklin FWCB part number above. For the 0.5 micron Big Blue variants, contact Cleanflow to confirm the legacy part number mapping.
Buy Big Blue Carbon Block Filters from Cleanflow
Cleanflow Utility Supply Company carries the Franklin FWCB Big Blue carbon block filter in both 10" and 20" lengths, 0.5 and 5 micron. Browse the full Big Blue Water Filters collection or explore the complete Franklin Water lineup. Sold individually, in packs of 6, or packs of 12.
Need the standard 2.5" format? The FWCB 2.5" x 10" and FWCB 2.5" x 20" fit slimline housings. Looking for a complete kit? The Big Blue Triplex Replacement Kit bundles this carbon block with two sediment pre-filters. Free shipping on orders over $199. 30-day return policy. Email info@cleanflow.ca for volume pricing.
Frequently Asked Questions
What is the difference between the 0.5 micron and 5 micron versions?
The 0.5 micron provides finer particle removal and higher chlorine reduction capacity (70,000+ vs 60,000+ gallons for the 10" BB). The trade-off is higher initial pressure drop (4.5 psid vs 3 psid at 3 GPM). Choose 0.5 micron for RO pre-filtration or where maximum chlorine removal matters. Choose 5 micron for general whole house use where lower pressure drop is preferred.
How long do Big Blue carbon block filters last?
Depends on the variant and your daily water usage. The 10" BB at 5 micron lasts 60,000+ gallons. At 200 gallons per day, that's roughly 10 months. The 20" BB at 0.5 micron lasts 150,000+ gallons. Replace sooner if chlorine taste returns or pressure drop rises to 1.5 Bar (22 psi) above the clean-cartridge baseline.
Are these filters safe for drinking water?
Yes. NSF 42 and NSF 61 certified for material safety requirements. The certifications confirm the materials are safe for contact with potable water. The chlorine reduction capacity is based on the manufacturer's own laboratory testing.
Do these filters remove bacteria?
No. Carbon block filters reduce dissolved chlorine, taste, and odor through chemical adsorption. They are not microbiological purifiers. Franklin recommends multiple disinfection barriers where raw water may contain pathogens.
What sediment filter should I use before this carbon block?
Install a FWPS melt blown sediment filter upstream to protect the carbon block from premature loading. A 5 or 20 micron sediment pre-filter catches sand, silt, and rust before they reach the carbon media. The Big Blue Triplex Kit includes both sediment stages and this carbon block as a ready-to-install set.
Can this filter be used with RO systems?
Yes. Use before the RO membrane to reduce chlorine (which damages membranes) and after the membrane to polish taste. The 0.5 micron variant provides the tightest pre-filtration for membrane protection.
Manuals & Documentation
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