Pentek GAC-20bb Granular Activated Carbon Whole House Water Filter Cartridge, 20" X 4.5" (item #155249-43)

Item #: 155249-43 (GAC-20BB)
Dimensions: 20" x 4.5" (Big Blue)
Media: Granular activated carbon (GAC)
Post-Filter: 20 micron (reduces carbon fines)
Pressure Drop: 5 psi @ 4 GPM
Capacity: 25,000 gallons @ 4 GPM
Certification: NSF/ANSI Standard 42 (material safety only)
Temp Rating: 40°F–125°F (4.4°C–51.7°C)
Compatible Housings: Pentek Big Blue, Culligan, Ametek, US Filter, Plymouth, Kleen Plus, American Plumber, Bruner, and most other 20" Big Blue housings

Improve the taste and smell of your whole house water supply with the Pentek GAC-20BB replacement cartridge (Item #155249-43). Sized for standard 20" Big Blue filter housings, this granular activated carbon (GAC) cartridge is engineered to effectively reduce bad taste and odor along with chlorine taste and odor, delivering cleaner-tasting water at every tap in your home.

The GAC-20BB's construction directs water in one end and through the entire length of the carbon bed before exiting the other end, maximizing contact time between water and carbon for optimal adsorption. An internal expansion pad minimizes channeling and bypass, while a permanently fastened 20-micron post-filter — secured to an innovative support basket — helps reduce carbon fines and other suspended particles from the filtered water before it reaches your tap.

Rated for a capacity of 25,000 gallons at 4 GPM with a 5 psi pressure drop, the GAC-20BB is a direct-fit replacement for most standard 20" Big Blue whole house filter systems, including Culligan, Ametek, US Filter, Plymouth, Kleen Plus, American Plumber, Bruner, and other compatible brands. Manufactured entirely from FDA-compliant materials, it's tested and certified by NSF International to ANSI/NSF Standard 42 for material safety, making it a reliable choice for residential, food service, commercial, and industrial applications — including addressing odor issues common in well water supplies.