Pentek EP-20BB Big Blue 20″ x 4.5″ Carbon Block Filter 5 Micron

The Pentek EP-20BB is a Big Blue 20-inch carbon block cartridge designed for whole-house or high-flow point-of-entry filtration where chlorine taste and odor reduction is a primary goal. Carbon block cartridges are commonly selected for city water applications to improve water taste and odor in showers, sinks, laundry, and kitchens. This cartridge installs in a compatible 20-inch Big Blue housing and is replaced on a schedule or when chlorine taste and odor return.

Model number: EP-20BB

Media type: carbon block cartridge

Cartridge size and housing compatibility

• Cartridge size: 20-inch Big Blue style (fits housings that accept 20-inch x 4.5 inch Big Blue cartridges)
• Housing compatibility: 20-inch Big Blue housings designed for 20-inch BB cartridges

What is the Pentek EP-20BB Big Blue 20″ x 4.5″ Carbon Block Filter Used For?

• Whole house chlorine taste and odor reduction for city water
• Point-of-entry carbon filtration where higher capacity and flow are needed
• Pretreatment to reduce chlorine exposure to downstream equipment (when applicable)
• Residential and light commercial applications where Big Blue cartridge capacity is preferred

Compatibility checks
Before ordering, confirm:

• Your housing is a 20-inch Big Blue housing (not a standard 10-inch or slimline housing)
• Your housing accepts 4.5-inch diameter Big Blue cartridges
• You have clearance below the housing to remove a 20-inch cartridge during service
• Your flow demand matches a Big Blue cartridge setup for your plumbing size and use

What’s included

• (1) Pentek EP-20BB carbon block cartridge
  Cartridges are sold individually unless the product page specifies otherwise.

Install difficulty: easy

Standard cartridge replacement in a compatible housing.

Installation Guidance for the Pentek EP-20BB Big Blue 20″ x 4.5″ Carbon Block Filter

1. Shut off water to the filter housing and relieve pressure using the housing pressure relief button if present.
2. Place a towel or pan under the housing to catch water.
3. Remove the housing sump using a housing wrench if needed.
4. Remove the used cartridge and clean the sump and O-ring groove.
5. Inspect the housing O-ring and replace it if worn, flattened, or nicked.
6. Insert the new EP-20BB cartridge and confirm it seats properly.
7. Reinstall the sump and hand-tighten. Do not overtighten.
8. Turn the water on slowly and check for leaks.
9. Flush the cartridge until water runs clear, then recheck for leaks.

Replacement Triggers
Replace the cartridge when:

• Chlorine taste or odor returns in showers, sinks, or drinking water
• Flow drops noticeably at fixtures
• Differential pressure increases across the housing (if monitored)
• You reach your planned service interval based on household use and water conditions

Maintenance Schedule for the Pentek EP-20BB Big Blue 20″ x 4.5″ Carbon Block Filter

• Inspect the housing O-ring and sealing surfaces at every cartridge change
• Replace the cartridge on a consistent schedule for best taste and odor performance
• Keep a spare cartridge on hand if chlorine taste and odor are a critical priority for the home

Common Questions on Carbon Block Cartridges

Q: What does the EP-20BB carbon block cartridge reduce?
A: It is commonly used to reduce chlorine taste and odor and improve overall water smell and comfort.

Q: What housing does the Pentek EP-20BB Big Blue 20-inch carbon block cartridge fit?
A: It fits 20-inch Big Blue housings designed for 20-inch x 4.5-inch cartridges.

Q: Is the Pentek EP-20BB Big Blue 20-inch for whole house use or under-sink use?
A: It is commonly used for whole house point-of-entry filtration in a Big Blue housing, but it can be used anywhere a compatible 20-inch Big Blue housing is installed.

Q: Will this soften water or remove hardness minerals?
A: No. Carbon filtration targets taste and odor, as well as certain chemicals. Hardness minerals require water softening or scale-focused treatment.

Q: How do I know when to replace the Pentek EP-20BB Big Blue carbon block cartridge?
A: Replace when chlorine taste or odor returns, flow drops, pressure drop increases, or you reach your planned replacement interval.

Q: Will a carbon block cartridge reduce my water pressure?
A: It can if the cartridge becomes loaded or if the housing setup is undersized for peak demand. Replacing on time helps maintain flow.

Q: Do I need a sediment prefilter before this cartridge?
A: If your water has noticeable sediment, a sediment prefilter can help reduce premature loading and extend carbon cartridge life.

Match your 20-inch Big Blue housing with the EP-20BB carbon block cartridge to keep chlorine taste and odor under control throughout your home.