---
product_id: 510577798
title: "- Pentair Pentek GAC-20BB Big Blue Granular Activated Carbon Water Filter, 20\" x 4.5\", Chlorine Taste Odor Reduction, NSF Certified, Pack of 4"
brand: "pentek"
price: "€ 739.24"
currency: EUR
in_stock: true
reviews_count: 13
category: "Pentek"
url: https://www.desertcart.gr/products/510577798-pentair-pentek-gac-20bb-big-blue-granular-activated-carbon-water
store_origin: GR
region: Greece
---

# 25,000 gal chlorine reduction 20" x 4.5" Big Blue drop-in fit NSF/ANSI Standard 42 certified - Pentair Pentek GAC-20BB Big Blue Granular Activated Carbon Water Filter, 20" x 4.5", Chlorine Taste Odor Reduction, NSF Certified, Pack of 4

**Brand:** pentek
**Price:** € 739.24
**Availability:** ✅ In Stock

## Summary

> 💧 Elevate your water game — because your home deserves the best sip!

## Quick Answers

- **What is this?** - Pentair Pentek GAC-20BB Big Blue Granular Activated Carbon Water Filter, 20" x 4.5", Chlorine Taste Odor Reduction, NSF Certified, Pack of 4 by pentek
- **How much does it cost?** € 739.24 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.gr](https://www.desertcart.gr/products/510577798-pentair-pentek-gac-20bb-big-blue-granular-activated-carbon-water)

## Best For

- pentek enthusiasts

## Why This Product

- Trusted pentek brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Certified Confidence:** NSF/ANSI Standard 42 certification guarantees safety and premium material quality.
- • **Seamless Integration:** Precision-engineered 20" x 4.5" size fits Big Blue housings for effortless replacement.
- • **Long-Lasting Performance:** Up to 25,000 gallons of chlorine reduction keeps your water fresh with fewer filter swaps.
- • **Advanced Filtration Design:** Internal expansion pad and post-filter trap carbon fines and prevent channeling for consistent flow.
- • **Pure Hydration, Zero Compromise:** Granular activated carbon slashes chlorine, taste, and odor for crisp, clean water.

## Overview

The Pentair Pentek GAC-20BB is a 20" granular activated carbon water filter cartridge designed for Big Blue housings. Certified to NSF/ANSI Standard 42, it effectively reduces chlorine, taste, and odor, delivering up to 25,000 gallons of cleaner water at a steady 4 gpm flow rate. Its advanced internal design minimizes channeling and carbon fines, ensuring consistent, high-quality filtration. This 4-pack offers extended, reliable performance for whole-house or commercial water systems.

## Description

The Pentair Pentek GAC-20BB delivers reliable granular activated carbon filtration for whole-house and commercial systems equipped with Big Blue 20-inch housings. Each cartridge reduces chlorine, taste, and odor using a proven GAC media bed, providing cleaner water at a steady flow rate with only 10 psi of pressure drop at 4 gpm.Engineered for consistent performance, the GAC-20BB features an internal polypropylene expansion pad that minimizes channeling and bypass, ensuring water passes evenly through the carbon bed. A spun polypropylene post-filter captures carbon fines before they reach your tap. Polystyrene end caps and outer casing provide structural integrity, while Buna-N and Santoprene gaskets ensure a secure, leak-free seal.Each cartridge is NSF/ANSI Standard 42 certified for material requirements and delivers up to 25,000 gallons of chlorine reduction capacity at 4 gpm. This 4-pack provides extended coverage for households and facilities that depend on dependable water filtration year-round.

Review: perfect fit - perfect repacement, good price for this filter, it was 2x the price at dealer, no issues.
Review: What a difference - I had a DIY dual filter setup with Pentek 158643 3/8" #10 3G Slim Line Clear Filter Housings for my cold sink water. A while back I downgraded to the cheap generic filters, and noticed a huge downgrade in taste. It was not drinkable water. So to fix it, I added a third Pentek filter housing, and went back to what worked- genuine Pentek filters. The sediment filter I had didn't seem to fit properly, I don't think it sealed at all, so I ditched that completely and used a cheap but working DuPont WFPFC8002 Universal Whole House Carbon Wrap 2-Phase Cartridge as a sediment filter. Second in line I swapped the $6.50 DuPont with the $9.63 Pentek CBC-10 Carbon Block Filter Cartridge, 9-3/4" x 2-7/8", 0.5 Micron, a solid secondary filter w/ a perfect fit. The Pentek feels like it weighs 3x as much as the Dupont, no question it's worth the few extra dollars. The third and final filter was the hardest decision. I have tried both the Pentek ChlorPlus 10 Carbon Block Filter Cartridge, 10" x 2-1/2", 1 Micron, and the Pentek CC-10 Coconut Carbon Drinking Water Filters (9.75" x 2.875"), both of which were fantastic, make a noticeable difference to the taste of the water, and costs about $15-20. Instead, I went with a $12 option, the Pentek GAC-10 Drinking Water Filter (9-3/4" x 2-7/8"), hoping it would deliver similar results, especially considering the town water is fairly clean to begin with, ppm around 48. Would probably go with the CC-10 next time, but I'm very happy with the current results. The Pentek filter and housing combo really restored my drinking water back to amazing. Neighbors knock at my door with 5 gallon jugs because they can taste the difference too.

## Features

- CLEANER, BETTER-TASTING WATER - Granular activated carbon effectively reduces chlorine, unwanted taste, and odor for improved water quality throughout your home or facility
- MINIMIZED CHANNELING AND CARBON FINES - Internal polypropylene expansion pad prevents water from bypassing the carbon bed, while a spun polypropylene post-filter traps loose fines
- NSF/ANSI STANDARD 42 CERTIFIED - Tested and certified by NSF International for material requirements, giving you confidence in the safety and quality of every cartridge
- FITS 20" PENTAIR PENTEK BIG BLUE HOUSINGS - Designed as a direct drop-in replacement cartridge (4.50" x 20") for Big Blue filter systems; operates at 40-125 degrees F
- 25,000-GALLON CHLORINE REDUCTION CAPACITY - Extended filter life at 4 gpm flow rate; this convenient 4-pack keeps your system running with fewer reorder interruptions

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B0BMFGX9JR |
| Best Sellers Rank | #8,643 in Tools & Home Improvement ( See Top 100 in Tools & Home Improvement ) #62 in Replacement Under-Sink Water Filters |
| Brand | Pentek |
| Brand Name | Pentek |
| Customer Reviews | 4.6 out of 5 stars 1,313 Reviews |
| External Testing Certification | NSF |
| Global Trade Identification Number | 30051678249438 |
| Item Dimensions D x W x H | 4.5"D x 4.5"W x 20"H |
| Item Type Name | GAC Carbon Water Filter |
| Item Weight | 20 pounds |
| Manufacturer | Pentair |
| Manufacturer Part Number | 155249-43 |
| Material | Activated Carbon,Carbon |
| Material Type | Activated Carbon,Carbon |
| Model Number | GAC-20BB |
| Number of Items | 4 |
| Product Benefits | Reduces Chlorine |
| Product Dimensions | 4.5"D x 4.5"W x 20"H |
| Set Name | 4 |
| Unit Count | 4 Count |

## Product Details

- **External Testing Certification:** NSF
- **Item Weight:** 20 pounds
- **Material:** Activated Carbon,Carbon
- **Product Benefits:** Reduces Chlorine
- **Product Dimensions:** 4.5"D x 4.5"W x 20"H

## Images

![- Pentair Pentek GAC-20BB Big Blue Granular Activated Carbon Water Filter, 20" x 4.5", Chlorine Taste Odor Reduction, NSF Certified, Pack of 4 - Image 1](https://m.media-amazon.com/images/I/71OBYDaBmAL.jpg)

## Available Options

This product comes in different **Size, Style** options.

## Customer Reviews

### ⭐⭐⭐⭐⭐ perfect fit
*by K***E on November 6, 2025*

perfect repacement, good price for this filter, it was 2x the price at dealer, no issues.

### ⭐⭐⭐⭐⭐ What a difference
*by P***E on March 24, 2019*

I had a DIY dual filter setup with Pentek 158643 3/8" #10 3G Slim Line Clear Filter Housings for my cold sink water. A while back I downgraded to the cheap generic filters, and noticed a huge downgrade in taste. It was not drinkable water. So to fix it, I added a third Pentek filter housing, and went back to what worked- genuine Pentek filters. The sediment filter I had didn't seem to fit properly, I don't think it sealed at all, so I ditched that completely and used a cheap but working DuPont WFPFC8002 Universal Whole House Carbon Wrap 2-Phase Cartridge as a sediment filter. Second in line I swapped the $6.50 DuPont with the $9.63 Pentek CBC-10 Carbon Block Filter Cartridge, 9-3/4" x 2-7/8", 0.5 Micron, a solid secondary filter w/ a perfect fit. The Pentek feels like it weighs 3x as much as the Dupont, no question it's worth the few extra dollars. The third and final filter was the hardest decision. I have tried both the Pentek ChlorPlus 10 Carbon Block Filter Cartridge, 10" x 2-1/2", 1 Micron, and the Pentek CC-10 Coconut Carbon Drinking Water Filters (9.75" x 2.875"), both of which were fantastic, make a noticeable difference to the taste of the water, and costs about $15-20. Instead, I went with a $12 option, the Pentek GAC-10 Drinking Water Filter (9-3/4" x 2-7/8"), hoping it would deliver similar results, especially considering the town water is fairly clean to begin with, ppm around 48. Would probably go with the CC-10 next time, but I'm very happy with the current results. The Pentek filter and housing combo really restored my drinking water back to amazing. Neighbors knock at my door with 5 gallon jugs because they can taste the difference too.

### ⭐⭐⭐⭐⭐ Smell and bad taste begone!
*by W***S on July 12, 2026*

The best 10” filter to get for taste and smell elimination. How often you need to change it depends entirely on how bad your water is.

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---

*Product available on Desertcart Greece*
*Store origin: GR*
*Last updated: 2026-09-02*