Having the best canister filters for your aquarium can make all the difference to your tank setup. However, most aquarium canister filters in the market are poorly built, difficult to maintain, and loud, making them a poor investment for your aquarium.

It can be rather challenging to find a suitable option for your 100-gallon aquarium. This is why we have curated a list of high-quality filters that will save you the trouble of manually cleaning your aquarium.

Let’s begin.

Comparison Chart

Product Name Ideal For Tank Size (in gallons) Flow Rate (in GPH) Type of Filter
The Fluval-FX6

400 563 canister filter
Penn-Plax Cascade 1000 Elite

100 265 canister filter
Marineland Magniflow Canister Filter

100 360 canister filter
SunSun HW703B 370GPH Pro Canister Fish Tank Filter Kit 


150 370 canister filter
Polar Aurora 4-Stage External Canister Filter

200 325 canister filter
EHEIM Classic External Canister Filter

66 116 canister filter
Finnex PX-360 Compact Canister Aquarium Filter

25 95 canister filter

Best Filter For 20-Gallon Aquariums – Handpicked Reviews

Here is the list of the best small tank canister filters in the market :

1. The Fluval-FX6 Filter


  • 400-gallon capacity
  • High flow rate
  • Sturdy design
  • 3-year warranty
  • Adjustable valves


  • Slightly expensive
  • Bulky body that is not ideal for tight setups

If you have a large aquarium that demands constant maintenance, the Fluval FX canister filter is a great option to consider. It is crafted with top-notch Italian architecture, high-quality parts, and a stunning design that makes it durable and attractive to look at.

It can pump up to 563 gallons of water per hour with a steady stream, which makes it ideal for keeping large fish, as they produce a lot of waste. Moreover, the Fluval FX canister filter has one of the highest storage volumes in the market, which makes it suitable for fish tanks with up to 400 gallons of capacity.

It is equipped with twin-emission nozzles that allow you to customize the flow rate so that you can use it in multiple-sized tanks without any trouble. Additionally, it has a silent yet heavy-duty motor designed to take up 10 percent less electricity while working at full efficiency.

It is also straightforward to set up, thanks to its intelligent self-priming design. All you need to do is add water and plug it in. The pump will monitor your water flow and adapt accordingly to keep a steady flow rate and expel the trapped air in the canister every 12 hours.

Cleaning the Fluval FX filter is also very simple. It comes with a multi-functional drain valve that allows you to empty the canister and drain your tank water for cleaning. Additionally, you also get a vacuum attachment to remove any gravel stuck inside the device conveniently.


The Fluval FX is a large canister filter that can cater to sizable tanks with up to 400 gallons of capacity. It is a fully automated and self-priming pump that is very easy to set up, making it ideal for office workers who cannot tend to their aquarium at all times, and beginners.

2. Penn-Plax Cascade 1000 Elite


  • High flow rate
  • Efficient media baskets
  • Simplistic design
  • Quick and easy monthly maintenance
  • Swimming pool style rotating valves with flow controls


  • Filter media is not readily available everywhere
  • It can be a bit noisy

Penn-Plax is one of the oldest and trustworthy brands in the market that makes premium products for aquarium enthusiasts. Even though they have several canister filters, the Cascade 1000 Elite is their best offering.

It is equipped with a soft sponge that provides a great surface for bacterial colonization and biological filtration. The filter also comes with a floss pad that captures minute dirt particles from the water and carbon media that remove contaminants.

Moreover, it is compatible with all types of filter media, so you can refill your canister without going through the trouble of finding specific supplements. You also get tubing interconnects that allow you to control the pump speed and rate of filtration inside your setup.

The Penn Plax Cascade 1000 strikes an appropriate balance between size and durability. It weighs only 12 pounds, and its tiny form factor allows you to easily carry it to the sink for quick cleaning.

You also get a set of all the required media included with every package. The installation process is extremely simple, and it doesn’t take longer than 20 minutes to set this thing up.


The Penn-Plax Cascade 1000 Elite is a compact and lightweight canister filter for 100-gallon aquarium with a flow rate of 265 GPH. It is one of the most silent filters in the market and offers a nice blend between high-end features and durability, making it worth checking out.

3. Marineland Magniflow Canister Filter


  • 3-year warranty
  • The auto-shutdown feature makes for quick cleaning
  • Quiet operation
  • Easy to clean
  • Simple setup


  • No valve switches to adjust the flow
  • It only comes with one type of media

The Marineland Magniflow Canister Filter is a heavy-duty and long-lasting device that ensures you get the best filtration for your fish tank. It has a rapid flow rate that can filter up to 100 gallons of water in no time.

It offers a versatile three-stage filtration system that is suitable for both saltwater and freshwater aquariums. The canister lid has an easy latch design that makes changing the media very simple but maintains a water-tight seal when submerged. One of the features we liked the most was its quick-release technology that isolates the motor for fast and easy cleaning.

The Magniflow has a stack and flow filter tray that prevents the water flow from entering the other stages of filtration, and it also includes bio-calls as the starting media. It also makes the best use of its polishing filter pads and filter foam pads to filter out even the smallest dirt particles from your aquarium.

Additionally, it has an effortless installation as you can easily latch it to the bottom of your aquarium. The top, on the other hand, is simple to take off for cleaning.


The Magniflow canister filter by Marineland is another excellent option to consider for 100-gallon fish tanks. It makes maintaining your fish tank effortless with its high flow rate of 360 GPH. And to make the deal even sweeter, you also get bio-balls as the starting media that works with its padded foam filters to make the water crystal clear.

4. SunSun HW703B 370GPH Pro Canister Fish Tank Filter Kit


  • It comes with a spray bar.
  • Simple and easy to clean
  • Three-stage filtration plus UV filter
  • High flow rate
  • Great features for a reasonable price


  • Poorly written labelings
  • It comes with only one type of media

The SunSun HW-703B kit is designed for filtering large-sized fish tanks with water capacities of up to 150 gallons. It has a speedy purification process, with an overall capacity of 370 GPH.

This filter has a built-in UV sterilizer that is ideal for killing microbial contamination that can pollute your aquarium water. In addition to that, it also features mechanical, chemical, and biological filtration with its carbon cushions, ceramic rings, and bio-balls that come included in the package.

It comes with four adjustable media trays, allowing you to tailor the filter setup to your fish tank’s specific requirements. This filtration system is packed with all of the expected accessories (nozzles, hoses, etc.) and has a self-priming piston, eliminating the need for manual tank siphoning.

The dirty water of your filter goes in through the inlet tube, and clean water is expelled out through its outlet tube, which also increases oxygen aeration levels within your tank. Additionally, the filter comes with the option to remove both these tubings and expel out the water inside for more accessible transportation and cleaning.

The HW-703B model includes a simple command and installation system. If you’ve never worked on setting up one before, that shouldn’t be an issue because the SunSun provides an excellent user-friendly manual with detailed instructions.



If you are looking for a high-powered filter for your 150-gallon fish tank, the SunSun HW-703B will not disappoint. It offers a multi-stage filtration system with a UV sterilizer that ensures proper hygiene within your aquarium. Furthermore, it is easy to set up and maintain, making it ideal for people with tight schedules.

5. Polar Aurora 4-Stage External Canister Filter


  • Compatible with all types of filter media
  • Self-priming pump
  • No manual siphoning required
  • UV sterilizer to kill bacteria and algae
  • Ultra-large capacity


  • Complex instructions
  • It can be a little noisy

Next, we have the Polar Aurora 4-Stage External Canister Filter that can fill up to 200 gallons of water at a remarkable filtration flow rate of 525 gallons per hour (GPH). With this sizable freshwater canister filter, you never have to be concerned about keeping your fish healthy.

The filter is manufactured to be fully automatic, so you won’t need to siphon the water manually for it to work. Its self-priming pump follows a simple plug-and-play design that is very easy to use, making it beginner-friendly.

The highlighting feature of this filter is the inclusion of UV lights and a 9-watt sterilizer. They help in keeping a check on algal and bacterial growth in your tank, so your fish never catch any diseases.

Additionally, it comes equipped with three flexible media trays that allow you to customize and add other filtration media. You can use activated carbons, ceramic rings, or bio-balls filter media to achieve excellent mechanical, chemical, and biological filtration. It also includes an adjustable spray bar, which helps shift the filter’s output flow.

Another noteworthy feature of this filter is its leak-proof design. The filter comes with a handy O-ring that sits tightly in a circular opening under the lid. Although it may seem like a minor feature, it is critical to ensure that dirty water inside the filter does not seep back into the aquarium.


The Polar Aurora canister filter is designed to keep large aquariums with up to 200 gallons of capacity clean, with its high flow rate of 525 GPH. Similar to the SunSun HW-703B, it also features UV sterilization technology for full-scale maintenance of your aquarium. What sets this filter apart is that you can get all these features without breaking your bank.

6. EHEIM Classic External Canister Filter


  • Quiet
  • One-chamber design
  • Compact build
  • Energy efficient
  • Durable


  • Unaesthetic looks
  • Complex instructions

The EHEIM Classic External Canister Filter is an excellent option for cleaning small tanks with up to 66 gallons of capacity. It delivers a 116 GPH pump output that can clean your 66-gallon tank two times in an hour. It is also cost-efficient, with an energy consumption of only 8-watt per hour and an overall filter volume of 34 gallons.

The package also comes with four filtration media— the Ehfi Synth, Ehfisubstrate, Ehfifix, and Ehfimech. They help give a large surface area for beneficial bacteria to grow in your tank. And since all these are Eheim-branded media, you will not experience any compatibility issues.

This filter is famous for its durable one-chamber design, which lets users mix-match and customizes the desired set of filtration media they want in the filter. This compact filter is designed to prevent water bypass, and even with the media installed, it can handle a reasonable volume of water. It runs very steadily and creates no noise at all.

It has a premium design quality, and its plastic architecture is exceptionally well built. It can withstand accidental drops and regular wear and tear. All the hoses are well-made, and you will not have to worry about any leaks and breaks. The pump head is compact and has a secure locking mechanism that holds it tight to the filter body.

When it comes to maintenance, this filter is relatively easy to clean. You can dismantle the unit into its individual parts and wash them separately. However, it requires priming to get it up and running.


If you’re looking for a small canister filter, the EHEIM canister filter is only 14 inches tall and weighs just 4.5 pounds for easy installation. It can clean small-sized tanks with up to 35 gallons of capacity, and its sturdy design and compatibility with different media will let you get the most out of it.

7. Finnex PX-360 Compact Canister Aquarium Filter


  • Compact and versatile
  • High build quality
  • Whisper-quiet operation
  • It can also function as a HOB Filter


  • Hoses are not long enough to put underneath your aquarium
  • It only comes with 90-degree connectors

The Finnex PX-360 is a compact and affordable canister filter that is ideal for tanks up to 25 gallons in size. It has a decent flow rate of 95 GPH, which is strong enough to keep small saltwater or freshwater aquariums clean.

This filter also packs two stackable media trays that include filter media and an extra sponge strainer. Additionally, the PX-360 is compatible with all types of filter media, so you don’t have to be concerned about finding suitable options for media replacement.

Even for a filter that costs less than $50, the Finnex PX 360 is a complete package, and you won’t have to make any aftermarket purchase to get it up and to run. What’s even better is that it can be configured to function as a HOB filter, which makes it affordable and versatile.

The PX-360 also lets you use the included spray bar to disperse water flow across the aquarium or a spray nozzle for a greater flow.


The Finnex PX-360 filter is a compact and budget-friendly option ideal for small tanks that can hold up to 25 gallons of water. However, don’t let its small size fool you into thinking that you’re missing out on anything. This filter offers well-rounded cleaning, and it can even function as a HOB filter for more versatile use.

Buying Guide: Best Canister Filters For Aquariums

Here is a buying guide to help you assess what you’re exactly looking for in a canister filter. Consider the parameters below before choosing the best option for your tank.

– Size of your Aquarium

Perhaps the most underlooked criteria, the size of your aquarium, is crucial in identifying which filter suits you the best. An ideal rule of thumb is to get a filter that can process four times the capacity of your fish tank in an hour. This figure is called the GPH (gallon per hour) rating of your filter.

It is always preferable to get a filter that can handle water capacities more extensively than your aquarium. That is because you can always tweak the flow rate of an overpowered filter to best suit your aquarium. However, an underpowered option will be restrictive and not be able to clean your aquarium correctly.

– The Valves

Canister filters typically come with two valves: one for intake and one for output. You should search for valves that can be sealed completely. This confirms that the water will remain in the hoses and that you will not have to prime your filter again whenever you dismantle it for servicing.

Another helpful advantage is being able to detach the intake and output hoses. This way, you can connect a gravel vacuum or adapter to the filter. Also, see if your filter can help with fluid changes, removing the need to fill buckets every time.

– The Motor

Your filter will be active 24 hours a day, seven days a week. Therefore, you need a long-lasting motor that also shouldn’t be a blow to your electricity bills. The best thing to do is to look for a motor with a UL approval rating, which assures that it has been tested to perform up to standards.

There are two kinds of motors to keep an eye out for – epoxy-sealed motors and magnet-driven motors.

Epoxy-sealed motors are by far the most popular and silent type of canister filter motor. They are installed in the head with the turbine flip side, which is advantageous because it restricts moisture, dust, or debris from damaging the impeller.

On the other hand, magnet-driven motors are self-priming, which avoids the hassle of manually siphoning the water but aren’t entirely sealed like their counterparts.

– Noise

While canister filters usually are quieter than other units, they still create some noise. The noise levels in the aquarium can have a massive impact on the health of your fish. This is true, especially if you have lots of small fish that are stressed easily.

A lot of companies provide decibel ratings for their filters. You should not dismiss this detail. The real noise levels will be affected by the location of the filter and the style of your tank cabinet. However, decibel ratings can provide a good indication of what to expect.

– Cleaning Convenience

Cleaning and maintenance is another important consideration you must give while selecting a canister filter. Based on the biological load of the tank, most filters will require regular maintenance about four times a year or so.

To keep things simple, look for canister filters that can be conveniently closed off and opened. Some filters include shutoff valves and other functions that will be extremely useful for cleaning the device. Look out for such filters and consider investing in them.

Why Should You Get a Canister Filter for Your Aquarium?

Canister Filters is a self-contained unit that pumps water from the fish tank using a siphon. It then circulates the water across several filtration media, including mechanical, biological, and chemical filter media to capture the basics. After all kinds of pollutants and bacteria are filtered out, the pump directs the purified water out. You can also get yourself a canister filter with heater functionality if you live in a cold region.

If you’re still not sure why a Canister filter would be the ideal choice for your aquarium, here’s a list of the benefits these fantastic units bring along.

– They are Versatile

Canister filters are highly versatile and can be paired up with a wide variety of fish tanks, irrespective of their size. It doesn’t matter if you want a canister filter for freshwater aquarium or salt water, as it can work seamlessly with both.

Your aquarium can be freshwater or saltwater-based, and this filter will work seamlessly with both.

Additionally, it also works excellent with turtle tanks which are a lot messier than standard fish tanks. In conclusion, no matter what type of marine life you wish to put inside your aquarium, you won’t have to look for another filter every time.

– Canister Filters Can Take Out Ammonia from Water Using Their Biological Filtration

One of the most common causes of pet fish death is the accumulation of ammonia in the water.

The decomposition of organic material produces ammonia, and the mechanical filtration in your tank may not be able to filter out the fish waste and uneaten food quickly enough to avoid the buildup of ammonia.

Luckily, a majority of canister filters come with biological filter media included in the package itself. These media host good bacteria that convert ammonia into lesser dangerous nitrogen compounds. It ensures that your fish are safe from ammonia poisoning.

– They are Quiet

Aquariums are soothing to look at, and that’s precisely why we set them up in our working and living spaces. But an aquarium with a constant loud buzzing sound can spoil the attractiveness of the entire setup. The unwanted noise can be irritating at times.

Moreover, it is also not healthy for your fish, especially if you have newborns in your tank. It can disorient and cause stress in them, which can develop health issues in your marine life.

Unlike regular filters, canister filters have a more silent functioning. They are a perfect option to install in your bedroom or workspace aquarium.

– Effective Chemical as well as Mechanical Filtration

Aquariums can quickly build up a lot of dirt from uneaten food and waste created by your fish. As mentioned earlier, it’s more of an issue with turtle tanks than ordinary fish tanks. Regardless, it is essential to have a mechanical filtration system set up in your aquarium to remove the larger particles that can contaminate the water’s quality.

Furthermore, we generally use tap water to fill up our aquarium, and it can have a lot of hard chemicals in it, such as chlorine, which can degrade your tank environment. To efficiently filter out the toxins and make the water crystal-clean, you also need a layer of chemical filtration.

That is why a majority of canister filters offer both mechanical and chemical filtration for the well-rounded maintenance of your aquarium.

– Easy to Setup

Canister filters are usually quite simple to install and maintain, particularly when compared to other types of fish tank filters. They are designed to be dismantled easily so that they can be cleaned. It is also generally straightforward to remove a filtration media and install a new one.

Even though it is not a pleasant task, cleaning water filters is considered a part of regular aquarium maintenance. However, with the best canister filters, cleaning will be neither difficult nor time-consuming.

Frequently Asked Questions

Here are a few commonly asked questions related to canister filters for aquariums:

1. What Size Canister Filter Do You Need?

When selecting the size of the filter, a good rule of thumb you can follow is that the larger your tank, the larger your filter should be. The exact potential and flow rate of a filter slightly drops when it is filled with the filter media completely.

For this reason, you may want to look into getting a canister filter with performance ratings that exceed your tank’s capacity. A more oversized and powerful filter is also advantageous because it results in cleaner water.

2. What Exactly Are Filter Media and Which Ones Do I Need?

Filter media is vital to clean the water in your tank. There are many options for each stage, but the most important ones are filter pads and floss, ceramic rings and bio-balls, and activated carbon.

For an advanced cleaning through canister filters, you also need to include ion exchange resins, phosphate absorbing media, and protein skimmers. It can further optimize their ability to clean the tank water.

3. How Often Should Your Canister Filter be Cleaned?

It all depends on your bioload and the fish you keep, but you should try replacing or cleaning your chemical and mechanical filter media at least once every month. To keep things running smoothly, you should clean the canister and motor at least once every 3-6 months.

We recommend running foam or sponges over consumable mechanical media like filter floss to save maintenance costs and retain extra beneficial bacteria.

4. Are Internal Filters Superior to External Filters?

Depending on your setup, either one of the two can be helpful in your aquarium.

Internal filters are typically less expensive than external units. On the other hand, external filters are much more efficient when it comes to sanitizing your aquarium water. However, if you own a mid-size tank, we recommend investing in an internal filter.

Depending on the type of filter media used, external filters are typically more expensive to operate, simply because the more extensive your canister filter is, the more filtration media it’ll need.

5. Do Canister Filters Make a Lot of Noise?

Canister filters are generally extremely quiet as compared to other filter system types. That is because they do not vibrate and creak as much as other filtration setups and separate pumps.

Furthermore, the filter’s architecture and the use of tubes to flow the water restrict noisy splashing. So if your canister filter is making an unusually loud noise, it might not be functioning correctly.

Final Thoughts

All the filters mentioned on our list are efficient, quiet, and work discreetly without being an obstruction in your tank. However, we think one canister filter stands out from the list.

The Fluval-FX6is the best performer on our list, delivering crystal clear water quality with its high flow rate and excellent filter media.

We recommend you evaluate what exactly your requirement is, using our buying guide, and then select the most fitting choice for yourself.

5/5 - (17 votes)


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