Fluval is known for being one of the leading brands on the market due to its high-quality products. However, before you buy any of their equipment it’s always important to make sure you’re getting something that’s going to last for years. This Fluval Fx4 Canister Filter review is going to let you know EXACTLY what you can expect!
Table of Contents
The Fluval Fx4 Canister Review (Is It Worth It?)
There’s a lot to know about the Fluval Fx4 before making an informed decision. So make sure you read the whole article before you buy to make sure it’s the right fit for you.
What’s Comes With The Fluval Fx4
There’s a lot to unpack when you open the Fluval Fx4, but don’t let that worry you. Setting it up is incredibly easy. Here’s everything you’re going to get
Smart Pump (auto-evacuates air and makes sure it’s always running as efficiently as possible).
2 Stackable Baskets.
Mechanical, biological and chemical filter media.
Anti-clog telescopic strainer.
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 easily attach the Fluval Fx Gravel Vac.
As you can see, the Fluval Fx4 has a lot of great features that come with it. But what does it all mean? Here are some of the most important questions answered.
What Is The Fluval Fx4 Flow Rate?
The Fluval Fx4 is able to pump 450 gallons of water per hour. If you have an aquarium you want the filter to be able to circulate four times the amount of water in the aquarium.
But don’t let this deter you if you have a smaller tank. The increased circulation in your tank will only help make it cleaner.
How To Slow The Flow Rate
If you plan on putting this in a smaller tank (I wouldn’t go smaller than 50 gallons) then you may need to slow the flow rate depending on the fish, like bettas for example. However, thankfully there are a few things you can do.
Angle The Output Into The Sides
One of the easiest things you can do is angle the output nozzles so they’re flowing into glass. This is what I do in my tank and it slows the rate of flow down quite a bit. It’s a simple solution and it’s not going to cost you any money.
Attach Filter Sponge To The Output Nozzles
Another thing you can try is adding filter sponge to the output nozzles. This is going to be a DIY job however, it’s fairly simple to do. You just need to find some filter sponge that’s big enough to fit around the nozzles and then cut a hole in it.
Once you’ve cut a hole in it, simply place the sponge over the nozzles and it will reduce the flow rate out.
Add A Spray Bar
This is one of the best options and it’s also incredibly cheap if you make one yourself. Adding a spray bar is going to dilute the flow from one or two strong currents, to a lot of weaker currents. You can even make flow bars yourself if you’re feeling inventive.
Close The Output Valve Slightly
Closing the output valve dramatically could damage the inside of your canister filter over time. However, if you close it ever so slightly, you’re going to be able to reduce the flow of water out of the filter and into your tank.
As you can see there are a lot of different methods to slowing the flow of water out of your tank. And if you use some of them in unison with each other then they’re going to work even better!
What’s The Minimum Size Tank You Should Use This For?
This tank can suit aquariums up to 200 gallons in size, however, if you have a smaller tank you may be wondering whether it’s right for you. It all depends on the fish you have and how creative you’re willing to get.
This filter would be good for any tank as small as 75 gallons and if you have the right fish then you could use it in a tank as small as 50 gallons.
Obviously, the key is making sure your fish are going to be happy with the flow rate. Bettas, for example, don’t like a strong flow, so if you use this for a 50 gallon with a betta in, then you’ll need to adjust the flow accordingly.
What Makes The Fluval Fx4 So Great?
This is a great little filter, and there are so many things that make it so great. Here are some of the best features, and the real reason you’re going to get it.
The Filter Media
The way the Fluval Fx4 has been made means that it has 5 stages of filtration in it. There’s mechanical filtration on the outside which water passes through, removing any debris. And then after this, it passes through the biological media. And lastly, you have the option of adding chemical filtration of some kind at the bottom of the filter.
(You always want chemical filtration to be last, because it’s the one that needs to be changed most often, and putting it at the end is going to keep it cleaner for longer.)
When you open the filter you’ll notice that there’s some extra space for more filter media, so what you want to add really depends on you. I’d recommend more Biomax media (it’s a shame more didn’t come with the tank). Or possibly an ammonia remover, or water polisher.
The only downside with the filter baskets is the lack of space. Even when you jam pack the baskets with biological media you may not have enough to take care of a 220-gallon tank. So you should only use it for smaller tanks.
The Self Primer
One of the best parts of the Fluval Fx4 and what makes it stand out from most other filters is the self-primer. Instead of priming this thing yourself, it’s going to take care of it all for you. Decreasing your workload even more!
(If you don’t prime a filter before using it, then it could end up causing the motor to burn out.)
With the Fx4 you just need to fill it up with water before you turn it on and then it’s going to be good to go. After that, it’s sort of set and forget as it’s smart pump technology takes care of the rest.
While it’s great that pump readjusts every 12 hours, you do need to check what time this happens. The readjusting is quite loud, so it’s going to wake you up if it happens at the wrong time.
If you’ve never had a self-priming tank before then don’t be alarmed when it happens. It can be quite unnerving the first time it happens, but it’s only going to last for a couple of minutes.
When it happens you’ll hear your filter stopping and starting as it makes sure any air in the filter has been emptied out. This will only last for 2 minutes.
The Purge/Utility Valve
Another great feature of this filter is the purge valve. Not only are you going to be able to attach the Fluval Fx Gravel Vac to it but it also makes it a lot easier to perform water changes.
Instead of having to slowly move buckets of water backward and forwards when you’re emptying the tank, you can just connect a hose to the utility valve and run it into your yard or anywhere you can get rid of the water.
The only downside is, that you’ll still have to add water back to your tank manually. While you could use a hose to fill the tank up by the filter, if the water hasn’t been treated then you’re going to kill any beneficial bacteria in your tank with the chlorine.
If you do plan on using the utility valve to empty your tank, make sure you turn your filter off first. And then all you have to do is let gravity do the rest.
How Does It Look?
The Fluval Fx4 is nice and compact, and it’s been made to fit into aquarium stands and small spaces. The exact measurements are 15.6 x 15.6 x 17.7, so if you’re not sure you’re going to have space it’s worth double checking.
And while you won’t be looking at the filter much, it does look exceptionally nice. It has a professional look, and while no filter is going to be the centerpiece of any home, if it does have to be on show then it’s going to fit in nicely.
How Easy Is The Fluval Fx4 To Maintain?
Maintaining and cleaning the Fluval Fx4 is incredibly easy as well. To get into the filter you just need to unscrew 8 screw clamps to take the lid off.
Once the lid is off you pull up two red levers which are on either side of the filter baskets, and then you’re able to pull out all of the filter media to change and clean as necessary.
If you want to get to the actual pump, then you’re going to need a crosshead screwdriver. To get to the pump you just have to remove 3 screws. Once the screws are out, simply pull it away, and you’ll get to the filter. Just make sure you don’t lose the sealing ring!
(And of course, you’re going to want to the canister to be empty of water first, otherwise, you’ll ruin the pump.)
The filter has been made with ease of maintenance in mind, so you’re not going to have to do anything difficult, labor-intensive or time-consuming. And it even has a dial that shows you when maintenance of the filter is required!
Is Setting Up The Fluval Fx4 Easy?
Just like with everything to do with the Fluval Fx4, setting up the canister isn’t going to require much brain power or effort on your part. In fact, it comes with extremely detailed instructions for what you’re going to need to do!
These instructions are so easy, that even if you’ve never set up a filter before you’re going to feel like a pro doing it.
The most difficult part of setting up the Fluval Fx4 is the inlet and outlet tubes. If they’re too long then you’re going to have to cut them to a size that’s right.
Make sure that you double check where you’re going to cut them beforehand because the last thing you need is to cut them too short.
But apart from that, the setup couldn’t be simpler.
Unpack and wash all the media in conditioned tap water.
Place the bottom canister basket into the filter and add the media, and then place the top one in and fill with media. Once you’ve done this use the red handles to lock them in place.
Add water to the canister and close the lid. Make sure when you’re screwing the lid in place you don’t screw them up in a circle but rather you go from opposite ends. This is going to stop the filter lid from being out of place or bending in certain areas.
Attach the inlet and outlet tubes and then place them in your tank. At this point, if you plan on using a spray bar you should also add it to the end of the outlet tube.
Once you’ve done this, your filter is going to be set up and ready to go! Just make sure that you’re following the step by step instructions that come with the filter though!
How Noisy Is The Fx4?
For the size of the canister, you’ll be surprised at how quiet it runs. The only time it’s going to make a lot of noise is when it’s clearing itself of air every 12 hours. However, when this occurs most of the noise will be coming from your tank, not the filter itself.
While it’s not going to be dead silent due to its powerful filter, it’s still quiet enough that it’s not going to be noticeable in your home.
Fluval Fx4 Canister Filter Review Recap
Now that the Fluval Fx4 Canister Filter has been reviewed, you should have a good understanding of what you’re going to get. For the most part, it’s a solid piece of equipment that you’re going to be happy with! Here’s a quick recap of the main points.
The flow rate on the Fluval Fx4 is very powerful, so if you plan on adding it to a tank with a betta or other fish who like a slow flow, you’re going to need to adapt it. There are a couple of ways you can do this including angling it against the sides of the tank, attaching a filter sponge to the nozzles, adding a spray bar, and closing the output valve slightly.
While this tank suits aquariums up to 220 gallons in size you can put it on a tank as small as 50 gallons.
The self primer feature is unique and it’s going to require less effort on your part.
The purge utility valve is a great way to make water changes a lot easier for you as well.
To maintain the Fluval Fx4 is nice and easy, the only difficult part is getting to the pump itself which will require you to use a screwdriver.
Anyone can set up the Fluval Fx4 and if you’ve never set up a canister filter it comes with simple instructions to show you how.
When you’re setting up the Fluval Fx4 make sure you don’t cut the input and output hoses too short or you will have to buy more.
The Fx4 can be quite noisy when it’s evacuating any air from itself. However, this only happens for about 2 minutes every 12 hours. Because of this, it might be a good idea not to keep it in your bedroom.
If you liked this review then you can go find more information about the Fluval Fx4 below. Otherwise, have a great day!
About the author
Hey there! I'm Antonio, the passionate owner and chief editor of Betta Care Fish Guide. With over half a decade of hands-on experience, I've become your go-to expert for all things betta and tropical fish.
Over the past 5 years, I've not only kept bettas and other tropical fish but also connected with a diverse network of hobbyists, seasoned fishkeepers, and even veterinarians.
Now, I want to help other beginner fish keepers who had the same questions as me when they were just starting out! So they can save themselves a ton of time and keep their fish happy and healthy!