---
product_id: 2221488
title: "U4 Poly-Carb Cartridge, Replacement Underwater Aquarium Filter Media, 2-Pack, A492"
brand: "fluval"
price: "€ 24.93"
currency: EUR
in_stock: true
reviews_count: 13
category: "Fluval"
url: https://www.desertcart.hr/products/2221488-u4-poly-carb-cartridge-replacement-underwater-aquarium-filter-media-2
store_origin: HR
region: Croatia
---

# Fresh & saltwater compatible Dual-sided chemical filtration 2-pack replacement convenience U4 Poly-Carb Cartridge, Replacement Underwater Aquarium Filter Media, 2-Pack, A492

**Brand:** fluval
**Price:** € 24.93
**Availability:** ✅ In Stock

## Summary

> ♻️ Keep your tank thriving with Fluval’s dual-action filter power!

## Quick Answers

- **What is this?** U4 Poly-Carb Cartridge, Replacement Underwater Aquarium Filter Media, 2-Pack, A492 by fluval
- **How much does it cost?** € 24.93 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.hr](https://www.desertcart.hr/products/2221488-u4-poly-carb-cartridge-replacement-underwater-aquarium-filter-media-2)

## Best For

- fluval enthusiasts

## Why This Product

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

## Key Features

- • **Compact Yet Powerful Design:** Small 2.8 x 2.8 x 1.8 inch cartridges pack a punch in maintaining optimal water quality.
- • **Trusted Legacy of Innovation:** From the pioneers of 3-stage filtration technology, Fluval guarantees industry-leading performance and reliability.
- • **Effortless Maintenance Upgrade:** Includes two cartridges designed specifically for Fluval U4 filters, ensuring seamless replacements.
- • **Precision Dual-Action Filtration:** Polyester side traps fine debris while carbon side eliminates odors and harmful substances for crystal-clear water.
- • **Versatile Aquarium Compatibility:** Engineered for freshwater, saltwater, and reptile tanks—perfect for any aquatic ecosystem.

## Overview

The Fluval U4 Poly-Carb Cartridge 2-Pack offers advanced dual-sided chemical filtration combining polyester and carbon media to remove fine debris, contaminants, odors, and harmful substances. Compatible with freshwater, saltwater, and reptile tanks, these compact cartridges are designed exclusively for Fluval U4 filters, ensuring easy replacement and superior water clarity backed by Fluval’s decades-long innovation legacy.

## Description

Fluval U4 Poly-Carb Cartridges has two unique filtering sides that combine to provide thorough chemical filtration, the crucial second stage in the filtration process. The polyester filter pad side filters out fine debris and contaminants. The carbon side filters out harmful liquid substances, colorants and odors. The Fluval Poly-Carb Cartridge helps keep your aquarium healthy and clean. For more fish tank accessories, check out other Fluval products including aquarium filters, aquarium heaters, aquarium air pumps, aquarium lights, aquarium rocks, aquarium thermometers, and aquarium stands. Fluval has a wide variety of products that are perfect for your pet fish to enjoy in any large fish tank, small fish tank, saltwater tank or freshwater tank. Fluval broke onto the aquatic scene in 1975 by introducing the world’s first 3-stage filter with synchronous motor technology – a breakthrough that is still applied in the industry today. Since then, Fluval has built a legacy around this pioneering spirit, relentlessly adapting in a changing world to launch innovative aquarium products that remain at the forefront of technology, and which set the bar in quality, style and functionality. Fluval’s mission is not just about building products that mimic the natural world, but inspiring aquarists of all skill levels to enjoy and respect the hobby for generations to come.

Review: Works great! - Works great!
Review: Fluval filter change - Comes with 2 filters, Fluval official media, Fluval filters work well for my fish tank needs.

## Features

- Chemical filter media with two unique filtering sides that combine to provide thorough chemical filtration
- Polyester side filters out fine debris and contaminants
- Carbon side filters out harmful liquid substances, colorants and odors
- Suitable for freshwater, saltwater or reptile environments
- Includes two cartridges designed for use with the Fluvial U4 Underwater Filter

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B001XRVX8C |
| ASIN  | B001XRVX8C |
| Age Range Description | all ranges |
| Best Sellers Rank | #22,116 in Pet Supplies ( See Top 100 in Pet Supplies ) #212 in Aquarium Filter Accessories |
| Brand Name | Fluval |
| Color | No Color |
| Customer Reviews | 4.7 4.7 out of 5 stars (1,899) |
| Date First Available | August 19, 2004 |
| Date First Available  | August 19, 2004 |
| Department | Unisex-Adult |
| Department  | Unisex-Adult |
| Directions | Fluval Poly/Carbon Cartridges features two sides for effective chemical filtration, the crucial second stage in the filtration process. The polyester filter pad side filters out fine debris and contaminants. The Carbon side filters out harmful liquid substances, colorants and odors. For freshwater, marine or reptile environments. For U series filter model: U4 |
| Included Components | Fluval U4 Filter Poly/Carbon Cartridge |
| Is Discontinued By Manufacturer  | No |
| Item Dimensions LxWxH | 2.8 x 2.8 x 1.8 inches |
| Item Package Dimensions L x W x H | 10.55 x 2.64 x 1.42 inches |
| Item Weight | 0.05 Kilograms |
| Item model number | A492 |
| Item model number  | A492 |
| Manufacturer | Rolf C. Hagen (USA) Corp. |
| Manufacturer  | Rolf C. Hagen (USA) Corp. |
| Material | Plastic |
| Model Name | Fluval U4 Poly-Carb Cartridge, Replacement Underwater Aquarium Filter Media, 2-Pack, A492 |
| Number of Items | 1 |
| Product Dimensions  | 2.8 x 2.8 x 1.8 inches; 1.8 ounces |
| Size | 2 Count (Pack of 1) |
| Specific Uses for Product | Indoor |
| Style | Poly-Carb |
| Target Audience Keyword | fish |
| Warranty Description | Warranty |

## Product Details

- **Brand:** Fluval
- **Item Form:** Cartridge
- **Item Weight:** 0.05 Kilograms
- **Manufacturer:** Rolf C. Hagen (USA) Corp.
- **UPC:** 015561104920

## Images

![U4 Poly-Carb Cartridge, Replacement Underwater Aquarium Filter Media, 2-Pack, A492 - Image 1](https://m.media-amazon.com/images/I/519t8soBffL.jpg)

## Customer Reviews

### ⭐⭐⭐⭐⭐ Works great!
*by L***S on April 25, 2025*

Works great!

### ⭐⭐⭐⭐⭐ Fluval filter change
*by F***S on May 27, 2025*

Comes with 2 filters, Fluval official media, Fluval filters work well for my fish tank needs.

### ⭐⭐⭐⭐⭐ Go with the name brand and save a headache.
*by D***. on November 7, 2025*

If you don’t go with fluval name brand you have a 50/50 chance the filters are the correct length. I did this for a while to save a little money but more often than not I would have to double up the filters because they were the improper length. Also, not really worth it to fight with someone on a return like that. Go with the name brand

## Frequently Bought Together

- Fluval U4 Filter Carbon Cartridge
- Fluval U4 Internal Filter Foam Pad
- Fluval U Internal Filters Clean and Clear Cartridge, White

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**Shop now:** [https://www.desertcart.hr/products/2221488-u4-poly-carb-cartridge-replacement-underwater-aquarium-filter-media-2](https://www.desertcart.hr/products/2221488-u4-poly-carb-cartridge-replacement-underwater-aquarium-filter-media-2)

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*Product available on Desertcart Croatia*
*Store origin: HR*
*Last updated: 2026-02-24*