Whole House Water Filter Cartridge 4.5x20 CTO, 2 Pack

Whole house water filter replacement cartridge helps reduce chlorine, bad taste, and odor so every tap delivers fresher-smelling water. This 4.5" x 20" CTO carbon block cartridge is designed for high-capacity whole home filtration, supporting steady flow while trapping fine sediment down to 5 microns. Made with coconut shell activated carbon, it’s a practical fit for most standard “Big Blue” style housings.

• Delivers noticeable taste and odor improvement by reducing chlorine and common tap-water smells


• Fits most standard 4.5" x 20" whole house filter housings for fast, no-modification replacement


• Filters fine particles with a high-density carbon block design rated to 5-micron filtration


• Supports long service intervals with up to 100,000-gallon capacity (water quality dependent)


• Includes 2 cartridges for fewer reorders and easier maintenance scheduling

Keep your whole-home system performing at its intended level with a dependable CTO carbon block swap. The coconut shell carbon media targets chlorine taste and odor while the dense block structure helps capture small particles that can affect water clarity. Each cartridge is built for consistent performance and straightforward changes during routine upkeep. If you’re noticing off-tastes, lingering odors, or it’s time for your scheduled change, grab yours today and refresh your water at the source.

• Type: CTO activated carbon block replacement cartridge (whole house)


• Size: 4.5" x 20" (115 x 115 x 507 mm)


• Filter media: Coconut shell carbon block


• Filtration rating: Up to 5 microns


• Capacity: Up to 100,000 gallons


• Service life: 9–12 months (varies by water quality and usage)


• Quantity: 2-pack


• Net weight: 3.5 lb (1.6 kg) each