When we considered all the product features that would make up the best aquarium filter we thought about a few things like;
Healthy clean water
Maintenance & Cleaning
Depending on the type of filters you want to choose, keep in mind that some are best suited for different types of uses. Some are great for saltwater tanks while others are great for larger size aquariums over 100 gallons.
We decided to take a closer look at some of the best aquarium filters available to find the best models out there. Of the many models we’ve seen, these are the best aquarium filters to buy in 2021:
At the end of the day, whether you set up an internal fish tank filter or a canister, you want to know that the pump provides enough air and water flow through the filter media to encourage beneficial nitrifying bacteria growth, all while removing harmful waste and debris from your tank.
There are a lot of products out there, and we hope this article helps you pick a filter that’s just right for you.
Not everyone likes meticulously researching and cross-referencing features between different filters.
If you’re more interested in simply getting your tank up and running, take a look at these three filters–they’re three of the most popular aquarium filters on the market today and have many features included:
Top Pick #1: Fluval FX6 Canister Filter – Best Aquarium Filter For Large Tanks
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Easily the best aquarium filter (spoiler alert: this is still my opinion) is the Fluval FX6. The Fluval FX6 won’t make sense for a ten gallon tank. But if you have a serious fish tank setup going and you want an excellent canister filter, the Fluval FX6 will give you the clean water you’ve always wanted, and your life a lot easier than other filters. This thing is a durable and well-built powerhouse for beneficial bacteria growth and biological filtration because of the amount of media this thing can house. Priming is a breeze, and giant media baskets with media are included.
Lastly, let’s not forget that it can filter tanks up to 400 gallons of water — one of the best fish tank filters around and suitable for large tanks. The Fluval FX series of the filter is available in two models that are more than suitable at removing any impurities in your freshwater or marine aquarium.
Watch this video from Fluval that details all the great options the Fluval FX series has to offer:
Of course, we live in a free-market society! We, the people, need options! And just like with filter brands, there are many great filters available…
Top Pick #2: Marineland Emporer Penguin Power Filter
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Crystal clear water and healthy fish are a hallmark of this Marineland Power Filter. This well built and durable filter has a high water flow rate, efficient filtration, and dual Bio-wheels combine to make this one of the best multi-stage filters on the market.
One thing I don’t like about this HOB is that you need to buy Marineland filter cartridges to see it run at it’s best. If you’re looking for efficiency, high water flow that is easily the best in biological filtration available, then you should be looking at the Marineland Emperor 400 Pro Series Bio-Wheel Power Filter. They have models that are suitable for most marine and freshwater tanks.
Watch this great video from Big Al’s about the Marineland Penguin HOB Filters:
Top Pick #3: Aqueon QuietFlow Internal Filter – Best Internal Aquarium Filter
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The Aqueon is a great small filter that has a motor with the ultra-quiet operation, has great water flow, and its easy installation and design can easily fit discreetly into any tank. It will also work in as little as 2 inches of water, so it would be great for a wide variety of uses.
Based on its low price, it’s the ability to filter 66 gallons per hour, quiet operation, and great reviews from all users, the Aqueon QuietFlow Internal Filter would be a suitable choice for any 10-15 gallon tank setups.
For a small fish tank filter, it has a lot of room for biological filtration, mechanical filtration, and chemical filtration. The filter cartridges that you insert are filled with activated carbon media. One of the best fish tank filters around.
Watch this unboxing of the Aqueon Internal filter from life with pets:
If you’re someone who wants to look at all the options before making the best choice for your filter, you’ll want to keep reading. We break it all down for you while we compare the best filters on the market–and we recommend our top picks in each category!
Looking For An Internal Filter?
If you know you want an internal tank filter, these reviews can help you make the right decision (the first time!):
So far, we’ve looked at what makes a good aquarium filter, the different types of filters, the best brands for tank filters, and we’ve seen a few of the most popular aquarium filters.
It’s now time for the main event–Buckle up for our look at the 29 best aquarium filters and stick with us as we recommend the best fish tank filter from each of the following types of fish tank filters:
Hang On Back (HOB) Filters
Small Tank Filters
You’ll continue to see helpful links to all our reviews for the filters shown in each category. When you see a filter you like, click the link to get the full scoop!
You’ll also learn the different functions and the pros and cons of each type of filter. And you’ll get our expert recommendation for the top filter in each category!
Let’s dive in!
Our Pick For The Best Canister Filter Fluval FX6 Canister Filter
External canister filters pack some serious punch in the filtration department. We went whole hog and reviewed 10 of the best canister filters, just for you.
If you read the Most Popular Fish Tank Filters section earlier in the guide, you already know how we feel about the Fluval FX6. It should come as no surprise that the Fluval FX6 is our number one pick.
Just in case you missed it, there are seven reasons why the Fluval FX6 is easily the best on the market (their nifty self-start feature is just the tip of the iceberg). Get the full scoop with our Fluval FX6 review.
Here’s the difference between the two Fluval FX models.
For all you small-tankers out there looking for a powerhouse canister filter for the ultimate clean tank, this article is the one for you.
About Canister Filters
The Canister filter is the most popular option for larger aquariums (40 gallons or larger.) Although, you can find them for smaller aquariums as well.
This filter type does not enter the water and is typically kept below the aquarium in the tank stand.
Canister Filter Pros:
Canister filters provide the best mechanical, chemical, and biological filtration. They also offer superior filtration as most canister filters are pressurized, so water is forced through a fine material that traps smaller particles. This helps improve overall water quality and the health of your fish.
These filter types often allow for the adjustment and addition of accessories like UV sterilizers, gravel filters, or a spray bar.
It easily has the best biological filtration on the market. The quiet operation, durability, and affordability make it an easy pick. That’s just the beginning–Read our full Marineland Emperor HOB filter review to learn everything you need to know about this HOB filter powerhouse.
There’s more to HOB power filters than just the Marineland Emperor Power Filter. Here’s the rest of the lineup:
This is an excellent buy if you want an affordable HOB filter that’ll still keep your tank clean and your fish happy
About HOB Filters
The Hang on Back Power Filter is the most common filter you will find because it’s easy to set up, and it’s easy to use and maintain. Plus, it does a great job filtering your aquarium.
How HOB Filters Work:
The filter itself never enters the water. As the name suggests, HOB filters hang on the back of your aquarium and suck tank water up a long tube. The water then goes through the filtration media. There are typically three chambers in HOB filters where nitrate and other toxins are removed from the water. The filter then sends the water back into the tank, clean and clear of toxins.
HOB Filter Pros:
It provides excellent three-stage filtration of aquarium water. It’s simple to assemble and relatively easy to maintain. Plus, with the HOB filter hanging outside your tank, they take up less space, so there’s no bulky filter to incorporate into your tank’s internal aesthetic and no bulky filter to hide in a cabinet underneath your tank. Most power filters will have an adjustable flow rate so you can set it specifically for your aquarium, and some power filters can be used on both freshwater and saltwater aquariums.
HOB Filter Cons:
You remove the good bacteria colony every time you replace the filter cartridges. It will always grow back, but it takes time. HOB filters have multiple cleaning steps, so they do take a little more maintenance than some other types of filters (like sponge filters, for example). And one of the most common complaints about HOB filters is the noise (They have gotten much quieter over the years, there’s still hope!).
While I love the benefits of a hang on the back filter, if you have 150 gallons or even 200 gallons of water to filter, then you should be adding multiple power filters or upgrading to a canister filter.
If you missed our HOB filters review link earlier, you’d want to check it out now.
Internal filters are quiet, inexpensive, and great for a smaller beginner’s tank. If that sounds like what you’re looking for, check out our other links to get a complete look at the best internal tank filters.
The standout feature that makes the Rio an excellent internal filter option, especially at its current price
Seven reasons why the Rio 90 Mini internal filter comes so highly recommended
A few of the things you should be aware of before you invest in the Rio
About Internal Filters
An internal filter is typically used in aquariums holding 20 gallons or less. The filter is mounted inside the aquarium with suction cups that keep the filter in place (like we mentioned–this is great if you want your aquarium to be flat against the wall).
Internal filters typically sit at the bottom of the aquarium and intake the impurities and help prevent debris from building up or settling on the bottom of the tank. If you have a larger tank and there’s a spot that your current filter doesn’t quite reach (known as a “dead spot”), an internal filter is a great way to bring water circulation to that area.
Internal Filter Pros:
If you do your research, you can find great internal filters for a great price. They are ideal for smaller aquariums with small numbers of fish.
Some versions of internal filters use air pumps and airlines, which help produce oxygenated bubbles (a good thing!).
Internal Filter Cons:
Internal filters are only recommended for smaller aquariums (unless you have a dead spot). So if you have a lot of fish in a large aquarium, you’ll have to spring for a bigger filter. If you have a really large aquarium, take another look at these excellent canister filters.
Our Pick For The Best Small Fish Tank Filter Aqueon QuietFlow 10 Power Filter
When it comes to “small” tanks, we’re referring to any tank under 20 gallons. The smaller the tank, the faster the toxins build-up–which means having a good tank filter is really important.
One of the biggest pitfalls most new Betta owners experience–and the surprising cause
The unfortunate tradeoffs of not using a filter in your small Betta Fish tank
The five best filters for small Betta fish tanks
Our Pick For The Best Sponge Fish Tank Filter Hydro 3 Sponge Filter
About Sponge Filters
The Sponge filter is the most simple to use and the easiest filter to understand. Its most common use is for small sensitive fish like the Betta. Its gentle performance is also perfect for newborn fry after breeding. It can really come in handy when your fish is sick, and you set up a hospital tank.
A sponge filter is used with an air pump, which pulls water through the sponge capturing debris.
Sponge Filter Pros:
The sponge filter is relatively cheap and very easy to set up. The design of the sponge filter allows good bacteria to live on the sponge. This means that, in addition to the mechanical filtration taking place, your tank is getting biological filtration, too.
Sponge Filter Cons:
Sponge filters can look large and bulky in your tank. Some air pumps can be pretty noisy, too. Most sponge filters are rated for tanks up to 10 gallons in size, which limits options for larger tanks. But there are solutions out there–multiple sponge filters in a single tank could provide adequate filtration rates. And some sponge filters pair well with certain HOB filters.
The 6 (surprisingly simple) things you need to build your own sponge pump
The 9 easy to set up steps to building and installing your very own sponge filter
Best Under gravel Fish Tank Filter Penn-Plax Premium Undergravel Filter
About Under gravel Filters
Under gravel, filters sit below the gravel (yet another filter name that leaves nothing to the imagination) and suck water and debris through the gravel. The idea is that the debris will get trapped in the gravel. Then the debris-free water passes up through the tubes. An airstone and air pump are attached to the top of the tube to create the suction.
Under Gravel Filter Cons (getting right to the point):
With under gravel filters, most beneficial forms of filtration don’t even occur. It’s a hard filter to clean and typically results in debris build-up at the bottom of your tank. That can lead to high levels of hydrogen sulfide…which you don’t want. Another con is that some with the use of an air pump you’ll be adding to the noise levels. Basically, you don’t even get the typical benefits of the three stages of filtration being mechanical biological and chemical.
Typically we don’t recommend this type of filtration for large community tanks or tanks with live plants.
Who makes the best aquarium filter? And why is it considered “the best”?
Most people consider clear water to be the number one indicator of a good filter. And while water clarity serves as the most obvious indicator of the filter doing its job, there are many other factors that you should consider when deciding which filter is the best for your fish tank.
We’ve got you covered.
Here’s what we recommend you look for during your fish tank filter search (in no particular order):
The price of the filter
The type of filter (i.e., HOB, internal, canister, sponge, undergravel…There are others but these are the most popular)
The types of filter media used (i.e., mechanical, biological, chemical, or a combination of these)
The ease of installation
How quiet or loud the filter is
The ease of maintenance (How complicated is the cleaning/maintenance process, and how often do you need to do that process?
The flow rate, input, output, and media parameters for the filter
The filter’s flexibility and customization options for flow rate and media
The recommended application of the filter (some filters perform better in specific environments/tanks and with certain fish)
“Quality of life” features that make the filter stand out from others in the market
A quiet filter is better than a loud filter… But what about the harder questions that you might not know the answers to? What about differences in flow rate? Which media types are best? How do you know which type of filter is best for your specific tank?
Those questions (and more) are answered throughout this guide. By the end, you’ll know:
If you should use a sponge or HOB filter, or spring for a canister filter
Which media filter combination is best
Which filters have worked for us and come highly recommended
And more–the answers are in this fish tank filter guide
Fish use the oxygen in water to breathe and, therefore, ensuring the quality of the water in the tank is of paramount importance. Use a filter or pump to ensure that the water contains enough oxygen for your fish. You may need to test the water for ammonia, nitrites and ph levels. – The Kernow Veterinary Group
The Filtration Process
Before you go ahead and select your ideal filter system, there are two things you should know.
Why you need a good aquarium filtration system
What does it do?
Let’s start with number 1 -Why you need a good filter system?
A good Filtration system is one of your most significant investments and can be the difference between an enjoyable hobby and a nightmare.
But selecting the right system can be tough since there are so many options.
Here are 9 Of the Most Common Aquarium Filter System Types:
Box or corner filters
Canister filters – Are used for large aquarium filter systems.
Fluidized Bed Filters
Power, HOB or Hang on Back Filters
Trickle (Wet/Dry) Filters – are a filtration system located under your tank.
Under Gravel Filters
We’ll go into each on in more detail below, but as you can see, if you don’t know the difference between a canister filter or a power filter, the decision can be a scary one.
Now let’s talk about the second thing you should know.
What Do They Do? How Do Fish Tank Filter Systems Work:
There is something about pictures that make things easy to understand.
Below you will see a diagram of a basic filtration system and how your aquarium water travels from the tank into your filter, through the media and back into the tank.
Note: The system or type of filter shown in this diagram is a HOB or Hang on Back Power filter.
However, some of us learn better by reading…
Aquarium filters help keep your tank clean and clear by eliminating harmful waste from your tank as the water pass through the filter media.
Solid Waste: The sponge or filter floss you place in your filter help trap any Dirt & debris that is floating around in the water. This is your mechanical filtration.
Organic waste: When you place activated carbon in your filter system, you are hoping it takes care of anything that is dissolved in your water that could be causing odor or discoloration. This is called your chemical filtration.
Biological Waste: Lastly, the most harmful toxins that are a result of the nitrogen cycle. Such as ammonia and nitrate are eliminated by your biological filtration, something like Seachem Biomax.
How to Set Up the Best Freshwater Aquarium Filtration System:
There are a lot of ways to set up a perfect filtration system, but there are also a lot of tips and tricks that pro fish keepers use.
Lucky for you, one of the best in the aquarium industry has compiled a video showing exactly how he sets up his fish tank filtration system.
The video is rather long.
However, I suggest you watch the whole thing before you decide on a filter for your tank to ensure you get the best system for your needs.
Here’s the video from Aquarium Co-Op and his take on setting up an aquarium filter system.
Now that you know a bit more about your aquariums filtration process. You should also know about a few of the other main functions of your filter before you buy a new filter.
The 3 Main Functions Of Your Fish Tank Filter System
Let’s start with the first.
1. Biological Function
The waste produced by your fish, uneaten food, decaying plants will create ammonia. In order to sustain life in your aquarium you must remove ammonia and your filters biological filtration provides a place for beneficial bacteria to grow, which in turn will turn your ammonia into nitrite and then nitrate as part of the nitrogen cycle.
2. Mechanical Function
Your filter floss or sponge is used to remove large particles and debris from your water. This helps to keep the water clean and clear.
3. Chemical Function
Water that you get from your tap, which most of us use for our aquariums will contain minerals, chemicals, and hard metals that can be bad for fish. Your chemical filtration, like carbon, will help remove some of these contaminants. Carbon can also help remove discoloration and odor from your tank.
What Are The Best Aquarium Filter Types [Video]
We get it–not everyone wants to read these days. If videos are your thing, this video from Howcast will scratch you where you itch.
It briefly describes what you can expect from certain filter types, and also has some handy, actionable tips for picking a filter you’ll be happy with.
It’s a quick watch (just two and a half minutes–even a goldfish could watch it), and it’ll prepare you for what’s to come in the rest of this guide!
Which Aquarium Filter Is Best For My Tank?
So how do you choose the right Aquarium Filter?
You want to do your research up front, so you aren’t wasting time and money with multiple filters. We’ve done that part for you!
Every filter has its pros and cons.
Canister filters typically cost the most but are the most effective at all three types of filtration and best suited for larger tanks. An under gravel filter may be the cheapest way to go, but it requires the most amount of maintenance and only provides biological filtration.
The money vs. maintenance tradeoff is just the beginning–the world of fish tank filters is full of tradeoffs and sacrifices (depending on how dramatic you are).
This simple table can give you a quick idea of what you can expect from each type of aquarium filter. But this isn’t an exhaustive list–don’t assume all HOB filters or all canister filters are made equal.
Additionally, there are two more considerations you should think about before you get a new filter for your aquarium.
Recommended Aquarium Tank Size & Water-Flow Rate For The Filter.
All filter types are not made equal. Some are made for large tanks and some for small tanks. When looking at the box for your filter, you will see that the manufacturer has indicated a recommended tank size.
Another thing shown on the filter box will be the GPH or Gallons Per Hour. This means how many gallons of water will pass through your filter every hour.
Depending on the type of fish and how many you intend to keep, I always recommend you filter the entire volume of your tank at least four times each hour.
A 20 gallon tank would need at least a filter rated for 80 gallons per hour. (4×20=80). However, I typically always go a little bigger just to be safe.
Best Fish Tank Filter Brands
Time to be candid–In my opinion, a great aquarium filter brand is Fluval. That’s 20 years of fishkeeping talking….
But, ultimately, it’s still just a personal preference. What works best for my tank setup and my fish might not work for yours. There are many excellent aquarium filter brands out there. This guide takes a look at a selection of the best options.
When looking at offers for a filter, be sure that the filter you get is equipped with a few of the following features or at least has some options and add on devices that might be included with higher-end models.
When looking at the filter motor, look for one that is energy efficient. Your filter will be running 24-7 all year long, so you don’t want something that will raise your power bill.
To be sure, look at the power cord; most will have a label with a UL approval rating. It might look something that looks like this:
Intake and Outtake Tubes:
When looking at the intake pipe, you want one that is adjustable so it can be made suitable for your specific needs. Nothing is worse than installing a filter that has an intake pipe that isn’t long enough to reach the bottom of your aquarium or worse way too short.
Another thing to look for is that some intake tubes have the ability to suck the oils and debris from the surface of the water, which helps ensure that your aquarium is getting the full benefits of the oxygen exchange.
Here you should look for an impeller that is protected from debris that could jam the impeller and damage the motor. The cover should come with a seal, gasket, or O-ring to ensure a proper seal.
Media Baskets Included
Chemical Mechanical Biological Media Included
Filter Cartridge Included
The filter is built well and durable
Easily Maintained and Setup
Accessories like surface skimmers
How much space does the filter need
Can it be used on a marine or freshwater tank
This isn’t an exhaustive list of what you would require, but if you’re at your local pet store, make sure that the filter you select includes many of the features listed above.
The biggest thing for me is how well the filter is at removing the impurities from the water column keeping the water fresh, clean, and suitable for the inhabitants of your aquarium.
The brand really doesn’t matter whether it’s an Aquaclear or a Tetra filter most models of filter will have at least a few of the features included and have no keeping the conditions in your tank filtered and clean.
What size filter should I get for my tank?
The simple way is to look at the manufacturer’s tank size, which is typically shown on the box. However, this is just a general guideline, and depending on your fish, you may need more or less. That said, I always start with a filter than can turn over my tank water volume at least 10x per hour. So for a 10 gallon tank, I would want something that is rated with at least 100 gallons per hour.
Is a bigger aquarium filter better?
You can never over filter an aquarium, and the more filtration you can provide is always a good thing. Just be aware that the larger the filter, the more powerful the flow rate will be, which can cause a powerful current that may be stressful for your fish. The most important thing to consider when looking for a filter is how much biological filtration and beneficial bacteria can be housed. Additionally, mechanical filtration should also be considered — lastly, chemical filtration, which arguably may not be required at all.
Should aquarium filters always be on?
Yes, if you have a filter, it should be running. As water moves through the filter, it is exposed to beneficial bacteria, it removes toxins, which helps keep your water healthy for your fish. The filter also provides a current in your tank to keep dead spots from forming in your aquarium, which could be deadly to your fish.
Can a filter be too strong for a fish tank?
Yes, depending on the size of the filter, the size of your tank, and the types of fish you keep. If your filter is too large, it could be creating too much current and flow, causing your fish to look for hiding places to rest. Some filters come with adjustable flow options included, which make the models suitable for a wider range of aquariums.
The Best Fish Tank Filter Survey
There was an interesting and enlightening survey from ThePetPlace.com and decided to include it (just for the halibut).
What good is an opinion if it’s not coming from an expert?
The survey asked for responses from 100 customers on which fish tank filter they prefer, which fish tank filter brand they prefer, and their top 3 recommendations.
On average, over 50% of those surveyed had between 5-10 years of experience.
This is awesome because we know we are getting some solid advice from experienced aquarists–when you’re looking for a great aquarium filter, go with the guidance of people who’ve set up their own tanks!
More than 60% had a freshwater tank size of 35-100 gallons with a medium bio-load.
This means that the preferred filters were strong enough for large tanks with the ability to handle dirty aquariums (that’s what we like to see).
75% of those surveyed preferred either a HOB Power Filter(35%) or a Canister Filter (40%).
Here are the results from the survey;
The Top 5 Preferred Filter Brands Were;
Marineland (Almost 50%)
Best Fish Tank Filters – The Top 3 Picks;
Marineland C-360 Canister Filter
Marineland Power Filter
Fluval 306 Canister Filter
Looking For More Filter Options?
There’s always more to *sea*! Check out these other articles on TFCG: