Fluval FX4 Review

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Fluval Fx4 Canister Filter Unbxoing

The Fluval FX4 is a high-performance filtering solution that’s easily one of the best when it comes to canister filters. Whether you’re talking to a beginner or a seasoned, Since its predecessors dominated the market for years, this filter has been on the shortlist for the best canister filters on the market and has developed quite a name for itself. 

This model more than makes up for its hefty price tag in terms of the quality it delivers and the ease with which it can be set up and then provide enough value to be used for years.

TypeExternal / Canister filter
Aquarium CapacityUp to 250 Gallons
Sutiable forAquariums
Filter Circulation450 GPH
Filtration TypeMulti-stage Filter
Biological Volume1 gallon
Mechanical Area217 in2
Pump Output700 GPH
Filter media includedMechanical, chemical and biological
Head height6.9 feet
Size15.75 x 15.75 x 16.5"
ExtrasSmart Pump Technology
for optimum filter performance,
efficiency and management

Fluval FX4 Overview

If you’re searching for a filter for your aquarium, which I’m guessing you are if you’re reading this, you’ve probably heard of Fluval and their line of aquatic goods, which includes the incredible Fluval FX4 and Fluval FX6 filters. 

Fluval Fx4 Canister Filter Unbxoing

They are considered one of the best in the aquatic community, and they outsell most other brands by a wide margin. And on that note, the newest member of Fluval’s FX Series comes with its elegant design and Smart Pump function, the Fluval FX4 high performance aquarium canister filter, which combines efficiency and practicality at an affordable price point. 

This product was made with care and much thought to the customer to the point where Fluval mentioned it as the smaller sibling of Fluval FX6. Fluval is quite a company, and its success stems from the fact that they have consistently developed high-quality goods that set the industry standard in many cases. 

Visibly, the Fluval FX4 is a fantastic example of this, confidently being shown off by Fluval as one of their best products, but will it live up to that expectation?

What is in the Box?

These products are all included with the filter and come with it when purchased. These products are all valuable and greatly appreciated because you’d have to purchase them separately if they weren’t included.

Fluval Fx4 Canister Filter Parts

Together with Fluval FX4 you will get:

  • Multi-directional output nozzles (which are great for helping you control the flow rate).
  • Utility valve and drain hose.
  • A connection port that allows you to attach the Fluval Fx gravel vacuum easily.
  • Anti-clog telescopic strainer.
  • Rubberized Feet
  • 2 Stackable Baskets.
  • Mechanical, biological, and chemical filter media.
  • Leak-proof valves.
  • Smart Pump (auto-evacuates air and makes sure it’s always running as efficiently as possible).

How to Set Up

Setting up this filter is the same as setting up any other filter. You assemble the media you’ll need and tweak everything to match your aquarium. The first thing to consider is the location. To get the most out of the canister filter, place it just beneath the tank and start adjusting the intake and output components.

Fluval Fx4 Canister Filter Set up

Click-fit connections, link them, and the locking clamps included in the package hold them in place. After that, you should set out the input and output nozzles, stretching from the canister, and cut the latter to extend one inch below the waterline on your tank. 

It’s also a good idea to cut the intake tube around 6 inches below the top of the aquarium and the stem should be cut 1 inch below the water’s surface. Most of the work is completed after the multi-directional output nozzle is secured to the end of the tube using a locking clamp. It’s now only a matter of filling the media baskets while avoiding leaks by leaving some room on top of each. 

Fluval Fx4 Canister Filter Set It up

After restacking the baskets, place them in the canister and hand tighten the screws to secure the filter’s cover. We placed a high value on ease of use in our review. The setup method is an excellent example of how the Fluval FX4 filter shines in both directions aside from overall performance, which is unmatched by any product.

Features of Fluval FX4

The Fluval FX4 Canister Filter has a long list of characteristics that allow aquarium owners to relax knowing that their tanks are in good hands by being sure that this filter will offer excellent performance and simplicity of maintenance.

Smart Pump Technology

As humans strive to have as few things as possible to worry about with the help of technology, the more prominent brands need to keep up with that in order to stay relevant to the market. Fluval “understood the assignment” and brought you a filter that’s way over the industry standard by being able to maintain itself without the need for your input. 

Fluval Fx4 Canister Filter Smart Pump

This might seem straight out of a sci-fi movie, but don’t worry, unlike the movies, these filters won’t hurt you in your sleep. On the contrary, they will help you to sleep better by giving you fewer things to worry about. This technology allows the trapped air to escape every 12 hours and then restart again. 

This will maintain the filter as if it’s performing on its first day, and you will barely have to even think about it. You’ll be surprised at how much effect this has on the overall health and performance of the filter and the tank itself.

Energy Efficient

We all know that energy just keeps getting more expensive every year, and it’s important to calculate the things in your home that might rack up that bill. A powerful filter might contribute to that by taxing on energy and only making that bill add digits. 

However, the Fluval FX4 external filter will gladly do the opposite by using a staggering 10% less than the model last year. This will save energy that is always good for the environment and save you money, which might seem like a bit of difference, but that translates to a surprisingly alarming sum at the end of the year.

Three-Stage Filtration

Fluval FX4 filter keeps adding to the list of impressive features with these three stages, which even though they are a must on every excellent filter- some don’t even bother. A three-stage filtration enables a correct cleaning of the water by taking care of grime and impurities and chemicals that are harmful to your fish and might even cost you their lives if you do not address the problem as soon as possible. 

Fluval Fx4 Canister Filter after Cleaning

Besides this, this filter can handle an astounding 700 hours of water per hour, which allows you to let the filter work all day adds up to 16800 gallons per day. I mean, those numbers are insane, and with the fantastic quality Fluval FX4 provides, your fish might even have a safer and cleaner environment than they would have in nature.

Water Changes and Gravel Cleaning

If you’re anything like me, you must be exhausted by the heavy lifting whenever it’s time to change the water. Apparently, Fluval also thought of this as a problem to be taken care of since this filter conducts the water changes with ease by refilling directly from the utility valve.

Besides the convenience of not having to channel your inner Paul Anderson with that heavy-lifting, there’s also another problem that needs solving, and that’s gravel cleaning. You’d be shocked by the number of impurities your little fish can produce, and all that waste gets accumulated between the little bits of gravel at the bottom of the tank. 

Don’t forget that that waste is multiplied by whatever amount of gravel you have on your tank. Hand cleaning hundreds of gallons of gravel doesn’t sound like the perfect weekend. That’s why Fluval thought of this too.

All of this is done by Fluval FX4 filter, so when its hose is connected to the utility valve at the base, does all the dirty work for you and you can spend your weekend staring at your phone like normal people.

Quiet Operation

It’s always a concern when picking an exterior canister filter that they’ll be noisy. After all, attempting to rest while sitting in a room with a continual groan or loud hum must be somewhat annoying, and if you’re part of the “I need complete silence in order to focus or sleep” group; in which case, welcome; a noisy filter will be a nightmare. 

However, with the Fluval FX4, you won’t have to worry about this because they are almost silent to the point where you have to be close to it even to tell it’s working. Fluval has used precision engineering to develop the quietest of motors combined with the use of bigger rubber feet, which reduce vibration noise and allow you to enjoy your aquarium and relaxation without being bothered by nerve-racking hums and vibrations.

Cleaning: How do You Clean a Fluval FX4?

The only time cleaning a filter is acceptable is when the flow remarkably slows down. For filters in general but especially this one, it’s advised not to be cleaned often, especially on a newly cycled tank. The recommended frequency would be 6 to 12 months, depending on the flow. 

Fluval Fx4 Canister Filter Cleaning

Filters like this work much better when left alone, and your interference might cause destroying your cycle rather than fixing anything. It rarely needs cleaning more than twice a year, especially with the Fluval FX4, that’s big and has quite a lot of media space. I

t takes quite a while to get clogged up, and even if you hit that 6-month mark unless you notice a visible change in its flow which is highly unlikely, we’d advise not to disturb it.

However, if you do have to clean it up, the cleaning is pretty straightforward. After opening it, make sure to be really gentle when squeezing the sponges in a bucket of tank water. You wouldn’t want to disturb the bacteria colony even more.


Just like Fluval FX6, this one makes the list of the best filters up to date and will definitely show its worth from the moment you unbox it to the months of usage after. Fluval FX4 filter also does most of what the Fluval FX6 does just in a smaller size. It’s a wise choice if you need a somewhat smaller filter in comparison that maintains the quality that the Fluval brand never fails to deliver.

However, besides the good things, it has similar to its predecessor it also has some of its negatives, like that price tag. Don’t get me wrong, for the value, it offers and considering it’s a one-time purchase, this one offers great value. However, for some people, the price point might be a little too much and that’s completely fine. 

We have a cheaper alternative by maintaining most of the features you must have in a filter. The Fluval 407 is the product that since it’s made by the same company offers that same quality of manufacturing that will provide you peace of mind when used. This one won’t break the bank and offer a similar approach to the Fluval FX4. 

It’s not easy to choose a filter, especially if you’re new to this. The important thing to keep in mind is those good quality products, usually come at a somewhat higher price-point due to the materials and masterfulness behind them.

This product seems like the perfect case of a “centerpiece” product of a company, considering that it’s made with much thought behind it and regardless of the cost, will definitely pay off by delivering unmatched performance.


The right canister filter can transform your aquarium water into a healthy one. Choosing the best external filter is often the hardest part. Read on for some frequently asked questions and answers on Fluval FX4 specification and operation.

Q: Is the Fluval FX4 loud?

As mentioned earlier, Fluval FX4 isn’t loud at all and will definitely not be a problem if you’re trying to relax near your fish. It’s built, in such a way, to minimize all noises coming from it and you won’t even know it’s on unless you’re close to the tank.

Q: Is Fluval 407 or FX4 better?

Each product has its own ups and downs. That’s why manufacturers come with different items so you are able to choose either based on your personal preference, budget, and needs of you and your fish. 

Where the Fluval 407 excels in smaller tanks, the Fluval FX4 is the obvious choice for tanks larger than 70 gallons due to the bigger flow rate and the filter circulation. So again, in case you’re striving for the most powerful filter of the two, go with the Fluval FX4. If you need just a general usage filter and you’re somewhat on a budget the 407 would be the way to go.

Q: How much power does a Fluval FX4 use?

The power-efficient technology has reduced the power usage to a surprising 30W power consumption for 2650l/h. Incredible statistics for such a powerful and well-built product.

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I am Mario, a experienced fish keepr and the editor-in-chief of Epic Aquarium.

At Epic Aquarium, we take our commitment to providing comprehensive and unbiased reviews very seriously. Our team carefully reviews each product, and we only recommend the very best in terms of quality. We also consult with leading fish keeper experts to ensure that each article is based on the most reliable and up-to-date information available.

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