---
product_id: 3678874
title: "Pentair Pentek GAC-20BB Big Blue Carbon Water Filter, 20-Inch, Heavy Duty Granular Activated Carbon (GAC) Replacement Cartridge, 20\" x 4.5\""
brand: "pentek"
price: "33558 som"
currency: KGS
in_stock: true
reviews_count: 13
category: "Pentek"
url: https://www.desertcart.kg/products/3678874-pentair-pentek-gac-20bb-big-blue-carbon-water-filter-20
store_origin: KG
region: Kyrgyzstan
---

# 25,000 gallon capacity Fits all 20" Big Blue housings NSF certified for safety Pentair Pentek GAC-20BB Big Blue Carbon Water Filter, 20-Inch, Heavy Duty Granular Activated Carbon (GAC) Replacement Cartridge, 20" x 4.5"

**Brand:** pentek
**Price:** 33558 som
**Availability:** ✅ In Stock

## Summary

> 💧 Elevate your hydration game with Pentair’s powerhouse carbon filter!

## Quick Answers

- **What is this?** Pentair Pentek GAC-20BB Big Blue Carbon Water Filter, 20-Inch, Heavy Duty Granular Activated Carbon (GAC) Replacement Cartridge, 20" x 4.5" by pentek
- **How much does it cost?** 33558 som with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.kg](https://www.desertcart.kg/products/3678874-pentair-pentek-gac-20bb-big-blue-carbon-water-filter-20)

## 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

- • **Advanced Carbon Tech:** Granular Activated Carbon maximizes contaminant adsorption for superior water quality.
- • **Post-Filter Perfection:** Built-in post-filter reduces carbon fines and suspended particles—no gritty surprises.
- • **Heavy-Duty Compatibility:** Seamlessly fits all 20" Pentair Big Blue and similar housings—upgrade without hassle.
- • **Long-Lasting Performance:** Filters up to 25,000 gallons—replace only every 6 months for uninterrupted freshness.
- • **Pure Taste, Zero Compromise:** Effectively eliminates chlorine taste & odors for crisp, clean water.

## Overview

The Pentair Pentek GAC-20BB is a 20-inch heavy-duty granular activated carbon water filter cartridge designed to fit all standard 20" Big Blue housings. NSF certified for safety and tested for performance, it effectively reduces chlorine taste and odors, delivering up to 25,000 gallons of clean, great-tasting water. Its integrated post-filter minimizes carbon fines, ensuring smooth, particle-free hydration. Ideal for professionals who demand reliable, long-lasting water filtration with minimal maintenance.

## Description

Pentair Pentek GAC Series Cartridges effectively reduce unwanted taste and odors, including chlorine taste & odor from your drinking water. Designed to allow maximum contact between the water and carbon ensuring optimal adsorption. The construction of the cartridge allows water to enter at one end and pass through the entire length of the carbon bed before exiting the other end of the cartridge, while an internal expansion pad minimizes channeling or bypass. Before the water exits the cartridge, a post-filter helps reduce carbon fines and other suspended particles from the filtered water. The post-filter is permanently fastened eliminating any potential for bypass. For best results, especially in high flow/high sediment applications, we suggest you team up a GAC post-filter with a Fibredyne pre-filter (Pentair Pentek FloPlus-20BB, EP-20BB, or C1-20BB) or an Extruded Carbon Block pre-filter (Pentair Pentek RFC-20BB or NCP-20BB).

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

- EFFECTIVE REDUCTION OF BAD TASTE & ODORS to provide good general-purpose drinking water
- FITS ALL 20" Pentair Pentek Big Blue or other 20" heavy duty housings and can replace any 20" x 4.5" carbon filter cartridge
- POST-FILTER HELPS REDUCE CARBON FINES and other suspended particles from the filtered water
- NSF INTERNATIONAL tested and certified for your peace of mind
- 25,000 GALLON CAPACITY. Replace every six months or when you notice a drop in water pressure or water quality

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B0014C067K |
| Assembled Diameter | 4.5 Inches |
| Batteries Included? | No |
| Batteries Required? | No |
| Best Sellers Rank | #7,023 in Tools & Home Improvement ( See Top 100 in Tools & Home Improvement ) #60 in Replacement Under-Sink Water Filters |
| Brand | Pentek |
| Color | Blue |
| Customer Reviews | 4.6 4.6 out of 5 stars (1,269) |
| Cutting Diameter | 4.5 Inches |
| Date First Available | December 17, 2001 |
| External Testing Certification | NSF, ANSI |
| Global Trade Identification Number | 00051678249437 |
| Included Components | filter |
| Is Discontinued By Manufacturer | No |
| Item Package Quantity | 1 |
| Item Weight | 5 pounds |
| Item model number | GAC-20BB |
| Manufacturer | Pentair Industries |
| Material | Pleated Carbon-Impregnated |
| Number Of Pieces | 1 |
| Number of Items | 1 |
| Part Number | 155249-43 |
| Pattern | Filter |
| Product Benefits | Reduces Chlorine |
| Product Dimensions | 4.57"D x 19.58"W x 4.57"H |
| Size | Pack of 1 |
| Style | 20" x 4.5" |
| UPC | 851905124281 051678249437 |
| Unit Count | 1.0 Count |

## Product Details

- **External Testing Certification:** NSF, ANSI
- **Item Weight:** 5 Pounds
- **Material:** Pleated Carbon-Impregnated
- **Product Benefits:** Reduces Chlorine
- **Product Dimensions:** 4.57"D x 19.58"W x 4.57"H

## Images

![Pentair Pentek GAC-20BB Big Blue Carbon Water Filter, 20-Inch, Heavy Duty Granular Activated Carbon (GAC) Replacement Cartridge, 20" x 4.5" - Image 1](https://m.media-amazon.com/images/I/21AKJjp5-wL.jpg)
![Pentair Pentek GAC-20BB Big Blue Carbon Water Filter, 20-Inch, Heavy Duty Granular Activated Carbon (GAC) Replacement Cartridge, 20" x 4.5" - Image 2](https://m.media-amazon.com/images/I/41legXLQnZL.jpg)
![Pentair Pentek GAC-20BB Big Blue Carbon Water Filter, 20-Inch, Heavy Duty Granular Activated Carbon (GAC) Replacement Cartridge, 20" x 4.5" - Image 3](https://m.media-amazon.com/images/I/41t7y57SGFL.jpg)
![Pentair Pentek GAC-20BB Big Blue Carbon Water Filter, 20-Inch, Heavy Duty Granular Activated Carbon (GAC) Replacement Cartridge, 20" x 4.5" - Image 4](https://m.media-amazon.com/images/I/51-4azPeWDL.jpg)
![Pentair Pentek GAC-20BB Big Blue Carbon Water Filter, 20-Inch, Heavy Duty Granular Activated Carbon (GAC) Replacement Cartridge, 20" x 4.5" - Image 5](https://m.media-amazon.com/images/I/517IL9S27DL.jpg)

## Questions & Answers

**Q: How come 1 is 50 dollars and a 2 pack is 200 dollars ?**
A: I haven't purchased this item lately, the $200 2 pack may be a for 2 2 packs.

**Q: Will it fit a culligan installed filter housing - a bb gac 20 ??**
A: The one I received was for a cullingan big blue filter collapsed blocking flow  and putting a lot of charcoal granules through out system. I have used these filters for years with little problem ,it may have been a fluke

**Q: What does bb mean? is it different from the gac-20?**
A: BB means that it is designed to fit our Big Blue housings which hold a 4 inch diameter cartridge rather than the standard 2.4 or 2.5 inch diameter cartridges. If you have additional questions, please reach out to our technical support team (USA based) at 800-279-9404.

**Q: How do you know when to change this filter?**
A: Vincent, If this is a residential application this filter should be replaced approx. every 6 months - 1 year. Never past 1 year. If you smell or taste chlorine or have an odor in your water the filter should be replaced. Let us know if this helps. Thanks, Paul.

## 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.

### ⭐⭐⭐⭐⭐ Awesome filter !
*by A***O on August 17, 2025*

There is a reason why they cost a bit more than most. They have a lot of granular carbon. You get what you pay for.. I have yet to install them in my 5 stage watts RO system. which has been resulting in 4ppm. for one year prior to changing all filters... The RO dow tech membrane i only replace every 5 years... my pre sediment is 1 micron ...

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*Product available on Desertcart Kyrgyzstan*
*Store origin: KG*
*Last updated: 2026-01-31*