---
product_id: 2858674
title: "Fluval U4 Underwater Filter, Freshwater and Saltwater Aquarium Filter, A480,Black"
brand: "fluval"
price: "6017040₫"
currency: VND
in_stock: true
reviews_count: 9
category: "Fluval"
url: https://www.desertcart.vn/products/2858674-fluval-u4-underwater-filter-freshwater-and-saltwater-aquarium-filter-a480
store_origin: VN
region: Vietnam
---

# 3-stage filtration system 3-way adjustable flow control flip-top cartridge access Fluval U4 Underwater Filter, Freshwater and Saltwater Aquarium Filter, A480,Black

**Brand:** fluval
**Price:** 6017040₫
**Availability:** ✅ In Stock

## Summary

> 🖤 Elevate your aquarium’s vibe with Fluval U4 — where sleek design meets powerhouse filtration!

## Quick Answers

- **What is this?** Fluval U4 Underwater Filter, Freshwater and Saltwater Aquarium Filter, A480,Black by fluval
- **How much does it cost?** 6017040₫ with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.vn](https://www.desertcart.vn/products/2858674-fluval-u4-underwater-filter-freshwater-and-saltwater-aquarium-filter-a480)

## 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

- • **Custom Flow Control:** Adjust output from top, middle, or bottom for perfect currents
- • **Triple-Stage Purity:** Mechanical, chemical & biological filtration for crystal-clear water
- • **Versatile Placement:** Horizontal or vertical setup adapts to any tank style or size up to 65 gallons
- • **Effortless Maintenance:** Flip-top lid for quick cartridge swaps without tank disruption
- • **Aquatic & Reptile Ready:** Engineered for freshwater, saltwater, and reptile environments alike

## Overview

The Fluval U4 Underwater Filter delivers advanced 3-stage filtration—mechanical, chemical, and biological—in a sleek, compact design. With customizable flow control and easy flip-top cartridge access, it’s perfect for freshwater, saltwater, and reptile tanks up to 65 gallons. Engineered for quiet, efficient operation, it adapts horizontally or vertically to fit your aquarium’s unique needs, making it the go-to choice for millennial aquarists who demand style and performance.

## Description

Fluval U4 Underwater Filter is ideal for use in all aquarium or reptile environments. Use the underwater filter as a primary filter in smaller aquariums or as a supplementary filter for larger aquariums. Fluval Underwater Filters with three-stage filtration are ideal for use in fresh, marine or reptile environments, and are also great for tanks with low water levels. Three-stage filtration with BioMax for superior aquarium water quality, flip-top access for quick and easy cartridge replacement, and three-way flow control make the new Fluval U Series the benchmark in underwater filtration. 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. 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: Internal vs. External Filters - There are many choices out there when it comes to filtration for your fish tank. Which of the many choices out there would make the best choice for you? Internal, or external? Are you looking for supplemental filtration, or primary filtration? In most situations, an external filter would be the better choice. Canister, power filter, wet/dry sump, refugium, all have the advantage of not taking up any space inside the fish tank. They are also all capable of holding more media than internal filters. However, some situations make it difficult to install an external filter on a fish tank. For example, if the tank is located in such a way that there are no available spaces behind, nor at the bottom, then your only choice might be to use an internal filter. For simple biological filtration, an air-driven sponge filter would suffice. However, a pump-driven internal filter offers increased circulation and better mechanical filtration. Let us say that you want an internal filter that is capable of providing complete filtration. Not just supplemental filtration but rather a single filter that can provide mechanical, biological, and chemical filtration. In that case, your choices will be limited. Most internal filters are designed to provide supplemental filtration. Most will provide mechanical and biological, but few of the designs will provide chemical filtration. The Fluval U-series of internal filters provide complete filtration, with the exception of the smallest model in the line up. This is the best internal filter that I have ever bought. An internal filter would not be my first choice. However, I was faced with a situation that would not have allowed the use of an external power filter. My choice then came down to between an internal vs. a canister filter. The tank will contain floating plants. Circulation needed to be gentle, and the surface of the water should be still. This filter met the requirements, without the maintenance hassle of having to use a canister filter. The filter was easy to install. The bracket system allows you to remove the filter, without having to remove the suction cups. The suction cups are attached to the bracket, and it is the bracket that holds the filter unit inside the tank. It is surprisingly quiet. You can adjust the output. Water can exit from the top, the middle, or the bottom of the unit. The middle output provides the most gentle flow. Mechanical filtration is provided by a coarse sponge, followed by a fine filter pad. The back of the filter pad is carbonized. This provides a little bit of chemical filtration. Biomax ceramic rings provide the biological portion of the filtration. All in all, a tidy, complete filter system. Disadvantages? It takes up a lot of space inside the tank. The small amount of carbon bonded to the filter pad is not enough to remove tannins from the water. And, it gets used up very quickly. It is possible that you may be able to remove the biomax and put pelleted carbon in its place. Another weakness is that the mounting bracket uses suction cups to attach to the tank wall. A truly modern filter design such as this should be using magnets instead of rubber cups. If you can use an external filter, that should be your first choice. They provide advantages at all three types of filtration (mechanical, biological, and chemical) over even the best internal filter out there. However, if you must have an internal filter, then this is the one that I would recommend. Any of the Fluval U-series, starting with the U2, all the way to the U4 will provide complete filtration. The smallest model, the U1, will not provide complete filtration. Highly recommended. This could be the best internal filter system available in the hobby, in the humble opinion of this reviewer. Please know that I do not own every model of internal filters out there. I am basing this on the ones that I have owned over the years, but there are a few models that I have not tried. However, I have researched the ones commonly available in the U.S., and this line appears to be the best out there. Consider your needs carefully before you decide. If ever Fluval were to discontinue this model, then you will find it difficult to find replacement media. It is not as easy to "create" your own media for this as it would be for an Aquaclear. But it can be done. You can buy bulk padding and cut them to the approximate size and shape of the plastic holder. For carbon, you can simply replace the biomax with large, pelleted carbon.
Review: Our Tadpoles *Love* It - I Posted a Photo - The Fluval 2 Water Filter is designed to work in a variety of configurations. This makes it absolutely perfect for tadpole tanks. You can put it sideways, just beneath the surface of the water. This creates a long "basking area" that the tadpoles absolutely love, while at the same time keeping their tank clean. I had no idea the Water Filter would be so ideal when I bought it. Sure, I knew it had a great reputation as a water filter, and that it could create a gentle stream. That is of course the big challenge with tadpole tanks. Tadpoles are MESSY - but they are also tiny and delicate. You want a filter that moves enormous amounts of water in order to keep the tank clean. At the same time, you don't want industrial-strength jets of water blasting into their swimming area. Especially when tadpoles are just developing their little arms and legs, getting hit with that water blast could cause all sorts of damage. The Fluval 2 Water Filter is very easy to set up. You decide what kind of output stream you want, set the speed, and voila. You stick the whole thing into your tank and you're set. I put it in sideways figuring it would take up the least amount of swimming space that way. I was completely shocked when I came back a few hours later and found six of the little tadpoles had wriggled their way on top of it and were soundly sleeping there. At first, I was worried. Would a little limb get stuck somewhere? Would the soft buzzing bother them? But no, it almost seemed soothing. They actively wrestle with each other to get onto that spot and, even if others come and pile on top of them, they lay there contented. It is really cute to watch them. They're like a pile of kittens. The water in the tank is absolutely much cleaner with this running. It does the best one could hope for against the output of these industrious little baby frogs. Highly recommended for tadpoles. Just install it sideways, just below the surface, so the little tadpoles can rest on top of it. There's lots of photos and videos of this in action all through the SuttonMass site. Ask if you have any questions!

## Features

- Use as a primary filter for smaller aquariums, or supplementary filter for larger aquariums
- Sleek design with easy grip water control panel and redesigned media cartridge to trap more debris
- Convenient flip-top lid allows for quick and easy access to filter cartridge for maintenance or replacement
- Position horizontally for shallow tanks, larger tanks with low water levels, or to create a decorative waterfall feature or vertically against aquarium wall to create currents or customized flow patterns
- Designed for freshwater, saltwater and reptile environments up to 65 gallons

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B001XRXY1G |
| ASIN  | B001XRXY1G |
| Age Range Description | All Life Stages |
| Best Sellers Rank | #14,188 in Pet Supplies ( See Top 100 in Pet Supplies ) #121 in Aquarium Filter Accessories |
| Brand Name | Fluval |
| Breed Recommendation | Medium |
| Color | Black |
| Country of Origin | Italy |
| Customer Reviews | 4.0 4.0 out of 5 stars (10,867) |
| Date First Available | August 19, 2004 |
| Date First Available  | August 19, 2004 |
| Department | men, women |
| Department  | men, women |
| Directions | Follow individual packaging instructions. |
| Is Discontinued By Manufacturer  | No |
| Item Dimensions LxWxH | 4.6 x 5.2 x 14 inches |
| Item Package Dimensions L x W x H | 14.02 x 5.2 x 4.49 inches |
| Item Weight | 2.46 pounds |
| Item model number | A480A1 |
| Item model number  | A480A1 |
| Manufacturer | Rolf C. Hagen (USA) Corp. |
| Manufacturer  | Rolf C. Hagen (USA) Corp. |
| Model Name | HAGEN FLUVAL U4 UNDERWATER FILTER |
| Number of Items | 1 |
| Product Dimensions  | 4.6 x 5.2 x 14 inches; 2.47 Pounds |
| Size | U4 |
| Specific Uses for Product | Indoor |
| Style | Underwater Filter |
| Target Audience Keyword | fish |
| 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… |

## Product Details

- **Brand:** Fluval
- **Capacity:** 240 Liters
- **Global Trade Identification Number:** 00015561104807
- **Included Components:** Filter
- **Item Weight:** 1.12 Kilograms
- **Manufacturer:** Rolf C. Hagen (USA) Corp.
- **Material:** Metal
- **Model Name:** HAGEN FLUVAL U4 UNDERWATER FILTER
- **UPC:** 015561104807 764999862437 155611048009 015561104784 015561104876 081175371515

## Images

![Fluval U4 Underwater Filter, Freshwater and Saltwater Aquarium Filter, A480,Black - Image 1](https://m.media-amazon.com/images/I/41T6Zfskp5L.jpg)

## 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

### ⭐⭐⭐⭐⭐ Internal vs. External Filters
*by C***I on February 22, 2014*

There are many choices out there when it comes to filtration for your fish tank. Which of the many choices out there would make the best choice for you? Internal, or external? Are you looking for supplemental filtration, or primary filtration? In most situations, an external filter would be the better choice. Canister, power filter, wet/dry sump, refugium, all have the advantage of not taking up any space inside the fish tank. They are also all capable of holding more media than internal filters. However, some situations make it difficult to install an external filter on a fish tank. For example, if the tank is located in such a way that there are no available spaces behind, nor at the bottom, then your only choice might be to use an internal filter. For simple biological filtration, an air-driven sponge filter would suffice. However, a pump-driven internal filter offers increased circulation and better mechanical filtration. Let us say that you want an internal filter that is capable of providing complete filtration. Not just supplemental filtration but rather a single filter that can provide mechanical, biological, and chemical filtration. In that case, your choices will be limited. Most internal filters are designed to provide supplemental filtration. Most will provide mechanical and biological, but few of the designs will provide chemical filtration. The Fluval U-series of internal filters provide complete filtration, with the exception of the smallest model in the line up. This is the best internal filter that I have ever bought. An internal filter would not be my first choice. However, I was faced with a situation that would not have allowed the use of an external power filter. My choice then came down to between an internal vs. a canister filter. The tank will contain floating plants. Circulation needed to be gentle, and the surface of the water should be still. This filter met the requirements, without the maintenance hassle of having to use a canister filter. The filter was easy to install. The bracket system allows you to remove the filter, without having to remove the suction cups. The suction cups are attached to the bracket, and it is the bracket that holds the filter unit inside the tank. It is surprisingly quiet. You can adjust the output. Water can exit from the top, the middle, or the bottom of the unit. The middle output provides the most gentle flow. Mechanical filtration is provided by a coarse sponge, followed by a fine filter pad. The back of the filter pad is carbonized. This provides a little bit of chemical filtration. Biomax ceramic rings provide the biological portion of the filtration. All in all, a tidy, complete filter system. Disadvantages? It takes up a lot of space inside the tank. The small amount of carbon bonded to the filter pad is not enough to remove tannins from the water. And, it gets used up very quickly. It is possible that you may be able to remove the biomax and put pelleted carbon in its place. Another weakness is that the mounting bracket uses suction cups to attach to the tank wall. A truly modern filter design such as this should be using magnets instead of rubber cups. If you can use an external filter, that should be your first choice. They provide advantages at all three types of filtration (mechanical, biological, and chemical) over even the best internal filter out there. However, if you must have an internal filter, then this is the one that I would recommend. Any of the Fluval U-series, starting with the U2, all the way to the U4 will provide complete filtration. The smallest model, the U1, will not provide complete filtration. Highly recommended. This could be the best internal filter system available in the hobby, in the humble opinion of this reviewer. Please know that I do not own every model of internal filters out there. I am basing this on the ones that I have owned over the years, but there are a few models that I have not tried. However, I have researched the ones commonly available in the U.S., and this line appears to be the best out there. Consider your needs carefully before you decide. If ever Fluval were to discontinue this model, then you will find it difficult to find replacement media. It is not as easy to "create" your own media for this as it would be for an Aquaclear. But it can be done. You can buy bulk padding and cut them to the approximate size and shape of the plastic holder. For carbon, you can simply replace the biomax with large, pelleted carbon.

### ⭐⭐⭐⭐⭐ Our Tadpoles *Love* It - I Posted a Photo
*by L***A on July 22, 2014*

The Fluval 2 Water Filter is designed to work in a variety of configurations. This makes it absolutely perfect for tadpole tanks. You can put it sideways, just beneath the surface of the water. This creates a long "basking area" that the tadpoles absolutely love, while at the same time keeping their tank clean. I had no idea the Water Filter would be so ideal when I bought it. Sure, I knew it had a great reputation as a water filter, and that it could create a gentle stream. That is of course the big challenge with tadpole tanks. Tadpoles are MESSY - but they are also tiny and delicate. You want a filter that moves enormous amounts of water in order to keep the tank clean. At the same time, you don't want industrial-strength jets of water blasting into their swimming area. Especially when tadpoles are just developing their little arms and legs, getting hit with that water blast could cause all sorts of damage. The Fluval 2 Water Filter is very easy to set up. You decide what kind of output stream you want, set the speed, and voila. You stick the whole thing into your tank and you're set. I put it in sideways figuring it would take up the least amount of swimming space that way. I was completely shocked when I came back a few hours later and found six of the little tadpoles had wriggled their way on top of it and were soundly sleeping there. At first, I was worried. Would a little limb get stuck somewhere? Would the soft buzzing bother them? But no, it almost seemed soothing. They actively wrestle with each other to get onto that spot and, even if others come and pile on top of them, they lay there contented. It is really cute to watch them. They're like a pile of kittens. The water in the tank is absolutely much cleaner with this running. It does the best one could hope for against the output of these industrious little baby frogs. Highly recommended for tadpoles. Just install it sideways, just below the surface, so the little tadpoles can rest on top of it. There's lots of photos and videos of this in action all through the SuttonMass site. Ask if you have any questions!

### ⭐ Can’t keep up with a turtle
*by T***A on November 20, 2025*

[UPDATE] I gave it one more try, did another full water change, cleaned the filter completely and put it in, the water was clean for 2 days then went right back to being murky. And no, this filter couldn’t even keep a 10 gallon tank clean, save your money and get a more reliable filter if you own a turtle I don’t know what I am doing wrong, but no matter what, water is always cloudy and smelly. First of all, this filter IS quiet, that is the one plus though. I clean it regularly, I have done water changes, but the water is never clear for long with this thing (and I mean more than a day). For reference I have a 44 gallon tank that is only filled about halfway. I have a turtle and a pleco. I thought this would be good since it says that it is also suitable for turtles, but it can’t keep up at all. I’ve adjusted the flow, checked if I installed something incorrectly, I even checked if it was an issue with the motor. It works perfectly fine, it just can’t keep up with a turtle. Maybe a smaller tank and a less messy pet.

## 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 Vietnam*
*Store origin: VN*
*Last updated: 2026-02-12*