---
product_id: 228949125
title: "U4 Underwater Filter"
brand: "fluval"
price: "A$289"
currency: AUD
in_stock: true
reviews_count: 8
category: "Fluval"
url: https://www.desertcart.com.au/products/228949125-u4-underwater-filter
store_origin: AU
region: Australia
---

# 3-stage filtration system ultra-quiet operation 3-way adjustable flow control U4 Underwater Filter

**Brand:** fluval
**Price:** A$289
**Availability:** ✅ In Stock

## Summary

> 💧 Elevate your aquarium game with crystal-clear confidence!

## Quick Answers

- **What is this?** U4 Underwater Filter by fluval
- **How much does it cost?** A$289 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.com.au](https://www.desertcart.com.au/products/228949125-u4-underwater-filter)

## 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

- • **Versatile & Reliable:** Ideal for 34-65 gallon tanks, perfect as a stand-alone or supplemental filter where external filtration isn’t an option.
- • **Whisper-Quiet Efficiency:** Operates silently to maintain a peaceful aquatic environment without disturbing your workspace or home.
- • **Crystal Clear Water, Fast:** Advanced 3-stage filtration removes debris, impurities, and optimizes biological balance for pristine aquariums.
- • **Customizable Flow Control:** 3-way adjustable output lets you tailor water flow perfectly for your fish’s comfort and tank setup.
- • **Effortless Setup & Maintenance:** Simple installation and easy-to-replace foam and carbon cartridges keep your aquarium thriving with minimal hassle.

## Overview

The Fluval U4 Underwater Filter delivers superior 3-stage filtration combining foam, poly/carbon cartridges, and biomax media to ensure optimal water clarity and biological balance. Designed for 34-65 gallon tanks, it features ultra-quiet operation and a 3-way adjustable flow control, making it perfect for fresh, marine, or reptile environments. Easy to install and maintain, this Italian-engineered filter is backed by a 3-year warranty, ensuring reliable performance and peace of mind.

## Description

Fluval U4 underwater filter with three stage filtration is ideal for use in fresh, marine or reptile environments. Stage 1 foam removes large particles. In stage 2, the poly/carbon cartridge traps fine debris, improves water clarity and removes impurities. In stage 3, biomax provides optimal biological filtration efficiency.

Review: An excellent filter - I had a cloudy aquarium with a filter priced 400 rs. It had to run for a week to make the water clear and the water flow was strong which made the fish hard to swim on their own. But this filter does magic. With in some hours after installation, the water became crystal clear. The flow is very smooth too.
Review: Worth evry penny! - Seller is amzing ! Fluval very good at making these stuffs ,I like seller response she was so good to solve issues etc.Price is good too!

## Features

- Filters debris and provides optimal biological filtration
- Simple to install and maintain
- Silent and efficient
- Ideal supplemental or stand-alone filter or for installations where external filtration is not possible
- Comes with 3-way flow control with adjustable output, 2 foam pads, 2 poly/carbon cartridges and 90 grams biomax
- Ideal for 34-65 gallon environments

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B001XRXY1G |
| Best Sellers Rank | #16,921 in Pet Supplies ( See Top 100 in Pet Supplies ) #304 in Filters (Pet Supplies) |
| Brand | Fluval |
| Brand Name | Fluval |
| Capacity | 240 litres |
| Container Type | Solid |
| Country Of Origin | Italy |
| Customer Reviews | 4.1 out of 5 stars 10,865 Reviews |
| Global Trade Identification Number | 00015561104807 |
| Included Components | Filter |
| Installation Type | Freestanding |
| Item Type Name | HAGEN FLUVAL U4 UNDERWATER FILTER |
| Item Weight | 1.12 Kilograms |
| Manufacturer | Rolf C. Hagen (USA) Corp., Rolf C. Hagen (USA) Corp. |
| Manufacturer Contact Information | Rolf C. Hagen (USA) Corp. |
| Material | Metal |
| Material Type | Metal |
| Model Name | HAGEN FLUVAL U4 UNDERWATER FILTER |
| Model Number | A480A1 |
| Package Information | Solid |
| Packer Contact Information | Rolf C. Hagen (USA) Corp. |
| Power Source Type | Corded Electric |
| Purification Method | Biological Filtration |
| Supported Water TDS Level Maximum (PPM) | 350 |
| UPC | 015561104807 764999862437 155611048009 015561104784 081175371515 |
| Unit Count | 1 Count |
| Warranty Description | 3 years; Fluval U Series Power Filters are guaranteed against defects in material or workmanship under normal aquarium usage and service for 3 years. We offer a 3 year guarantee on all nonreplaceable parts which means that the filter will be repaired or replaced at the manufacturer's discretion, free of charge, when the complete pump is returned with proof of purchase and postage paid. This warran… |
| Whats in the box? | Filter |

## Product Details

- **Brand:** Fluval
- **Material:** Metal
- **Capacity:** 240 litres
- **Included Components:** Filter
- **Installation Type:** Freestanding

## Images

![U4 Underwater Filter - Image 1](https://m.media-amazon.com/images/I/41T6Zfskp5L.jpg)
![U4 Underwater Filter - Image 2](https://m.media-amazon.com/images/I/519+9qLRuCL.jpg)
![U4 Underwater Filter - Image 3](https://m.media-amazon.com/images/I/51Lo1ZDpAfL.jpg)
![U4 Underwater Filter - Image 4](https://m.media-amazon.com/images/I/515zW-PSyTL.jpg)
![U4 Underwater Filter - Image 5](https://m.media-amazon.com/images/I/51qIoV6D6lL.jpg)

## Available Options

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

## Questions & Answers

**Q: Currently have a 10gallon but will upgrade shortly to a 30ish for a yellow eared turtle.  Does this sit on the bottom where it could suck in the food and waste that collects on the bottom where my river rocks are?  It has proven hard to get that out and the pleccu is not cleaning it up as of now.**
A: Mine is laying on the bottom of my tank and i have never had it sitting upright. I can tell you it does pretty well sucking everything up. However, i usually have one spot in the tank, right underneath the filter where debris sits. When I need to water change I just make sure I get the debris out with a fish net. That seems to work pretty well. It is the best filter I have had so far (with a turtle that has killed 4 filters), just make sure to clean the motor fan with every water change or filter media change.

**Q: Does the U4 filter have space to add activated carbon pellets?**
A: Yes it can, in the center of the filter there a removeable plastic cage. I put a small Chemi Pure bag in it. But I didn't care for this filter and not cause it didn't work. But I was wanting something more as a skimmer type filter and I wasn't getting enough flow out this filter unit. But it did work, if your running this on a smaller tank say no 30 gal freshwater ok. I was running it on a 29 gal reef tank with lots of live rock and it couldn't push enough water around it. But it did filter the water good.

**Q: Do all 3 outputs work at the same time?**
A: No, you have to pick a setting. I use mine for moving water in the bottom of my tank. It also seems to be he strongest setting out of the 3 choices

**Q: Can I change the direction of the water coming out of the nozzles? For example directing it upwards instead of horizontal.**
A: There's a small directional piece on the end of each nozzle you can turn to minimally direct the flow - but not nearly that much.

## Customer Reviews

### ⭐⭐⭐⭐⭐ An excellent filter
*by R***N on 13 March 2017*

I had a cloudy aquarium with a filter priced 400 rs. It had to run for a week to make the water clear and the water flow was strong which made the fish hard to swim on their own. But this filter does magic. With in some hours after installation, the water became crystal clear. The flow is very smooth too.

### ⭐⭐⭐⭐⭐ Worth evry penny!
*by S***L on 10 July 2022*

Seller is amzing ! Fluval very good at making these stuffs ,I like seller response she was so good to solve issues etc.Price is good too!

### ⭐⭐⭐⭐ Good, not great
*by V***S on 10 July 2020*

Underwhelming. Had read a lot of great reviews. But not delighted. Good design, no doubt. Easy to install, clean etc. Powerful motor. U3 working well in a 25 Gallon In my opinion, filter media volume is just too small. Mechanical filtration is inadequate and bio media is too small in volume. Sponge filter choked up in a week and when I pulled the tray out it spilled a lot of muck back into the water. Again, good product, but not great.

## Frequently Bought Together

- Fluval U4 Underwater Filter, Freshwater and Saltwater Aquarium Filter, A480,Black
- Fluval U4 Bio-Foam Pad, Replacement Underwater Aquarium Filter Media, A488
- Fluval U Underwater Filter BioMax

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*Product available on Desertcart Australia*
*Store origin: AU*
*Last updated: 2026-03-30*