10 Best Fish Tank Filters

BEST OVERALL

Polar Aurora Free Media 4-Stage External Canister Filter

PREMIUM CHOICE

Marineland Magnum Polishing Internal Canister Filter

GREAT VALUE

Penn Plax Aquarium Cascade Canister Filter

When it comes to searching for a filter for your aquarium, there are many things to consider and research. Not all filters are made the same or similar to one another. They come in many different shapes and sizes and will do various tasks for your fish tank. That’s why we’ve taken the time to look at the best fish tank filters to save you some research.

Table of Contents

BEST OVERALL

Polar Aurora Free Media 4-Stage External Canister Filter

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This external canister filter from Polar Aurora is a powerful option. It can handle fish tanks that are as large as 200 gallons and has a flow rate of 525 gallons-per-hour (GPH). It comes with everything needed for an easy setup, maintenance, and cleaning when required, making it a perfect filter for beginner fish keepers. It comes with a built-in UV light at 9-watts, which will promote clear water in your aquarium. This product also includes four media trays for various filtrations, such as chemical, biological, and mechanical, ensuring that your tank water is as clean and healthy as can be. A few other perks of this filter come with a self-priming pump, so manual siphoning is not needed. Finally, it includes an adjustable spray bar so you can control the water flow.

What We Like Most

Suitable for tank sizes up to 200 gallons

Comes with media trays for various filtration

Includes a built-in UV light at 9-watts

Has an adjustable spray bar

Easy to set up, maintain, and clean

Our Synopsis:

This filter is powerful and easy to use for beginner fish keepers. It will also keep your overall aquarium clean and healthy.

Analyst Rating

PREMIUM CHOICE

Marineland Magnum Polishing Internal Canister Filter

Read Customer Reviews Here »

Marineland is a well-trusted brand, and this internal canister filter will keep your tank clean and healthy to the max. It comes with two chambers to fill carbon or other media balls for various filtration. This canister will filter through your aquarium chemically, biologically, and mechanically. It will also give you crystal clear water through water polishing. The motor is submerged inside the water for a quiet filtration process, and there’s no backflush. This means if the motor stops working for any reason, such as the power going out, the dirty water will not pour back inside the clean fish tank. This product is not only easy to set up, but it’s also easy to take care of and clean when needed.

What We Like Most

Suitable for tank sizes up to 97 gallons

Includes mechanical, biological, and chemical filtration plus water polishing

Comes with a dual filter chamber

There’s no backflush

Easy to set up and maintain

Our Synopsis:

If you’re looking for something quiet and straightforward, this product may be the right choice.

Analyst Rating

GREAT VALUE

Penn Plax Aquarium Cascade Canister Filter

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Whether you have a freshwater tank or a saltwater setup, this Penn Plax canister filter may be a good choice for many reasons. This external canister filter can sit beside or underneath your aquarium and give your tank healthy, clear, and clean water. This filter goes through various filtration processes, such as mechanical, biological, and mechanical. It includes 360-degree rotation flow valves so you can control where you would like water to flow. Whether you have a large tank up to 200 gallons or something smaller, this filter will go through about 350 GPH. This product comes with everything you need, such as a spray bar, filter media, and tubing for an easy setup process. It’s simple to care for and to clean.

What We Like Most

Good for saltwater and freshwater tanks

Can work for aquarium sizes up to 200 gallons

Goes through mechanical, biological, and mechanical filtration

Has a 360-degree rotation flow valve

Includes everything for an easy setup

Our Synopsis:

This external canister is perfect if you’re looking for something to fit under your tank that has some bells and whistles included in getting the job done.

Analyst Rating

4

Penn-Plax Cascade 600 Submersible Aquarium Filter

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This is another excellent canister filter from Penn Plax. This internal filter will go through about 175 GPH for your tank that’s 20-50 gallons in size. It can easily filter through freshwater setups or marine aquariums. You can set this one up a few different ways so that it’s best for your fish and your tank’s overall look. This canister filter can be submerged inside your aquarium either horizontally on the floor with the water pushing up, or it can be placed vertically on the side or in a corner so that it’s out of the water. Alternatively, you can attach a spray bar and have the water cascade down back inside the tank as it goes through the filtration processes. It will chemically and biologically filter through your water, all the while aerating it and removing toxic chemicals, odors, and discoloration.

What We Like Most

Good for freshwater and saltwater tanks up to 20-50 gallons

Includes a directional water flow spout

Goes through chemical and biological filtration

Can be placed inside your tank horizontally or vertically

Comes with an internal sponge

Our Synopsis:

Depending on your tank’s size, you can place this filter inside any way you want as it gets the job done.

Analyst Rating

5

Penn-Plax Cascade Hang-on Aquarium Filter With Quad Filtration System

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This hang-on power filter is a good choice for a tank set up between 35 and 55 gallons in size. It will filter through about 200 GPH for your freshwater or saltwater fish. This product will promote crystal clear water in your tank as well as biologically, chemically, and mechanically filter and oxygenate your aquarium. It has an adjustable flow knob so you can control where the water goes during feeding times. It also comes with an internal sponge and bio balls that will remove ammonia and nitrite, and other harmful toxins from your aquarium. This power filter has a whisper-quiet motor so that you don’t even notice it’s there even though it’s still working well. Overall, this is an easy filter to set up. It’s also easy to maintain and clean.

What We Like Most

Good for tank sizes 35-55 gallons

Can be used for freshwater and saltwater aquariums

Has an adjustable flow control and a quiet motor

Includes biological, mechanical, and chemical filtration and oxygenation

Easy to set up and clean

Our Synopsis:

This is a simple power filter for beginner fish keepers.

Analyst Rating

6

Marineland Magniflow Canister Filter for Aquariums

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Similarly to the other Marineland filter on this list, this is a powerful external canister filter that will promote your aquarium’s healthy, clear, and clean water the entirety of the time it’s turned on. It can work for fish tanks that are up to 100 gallons, and you can use this filter for freshwater and marine setups. It includes 3-stage filtration, such as biological, mechanical, and chemical. It also provides water polishing for crystal clear water. Additionally, it has a valve block for a quick release for spill-free maintenance, stacked filter trays, and a prime button for easy startup. It’s simple to set up, easy to maintain, and to clean. Plus, it fits right underneath your aquarium so it can be hidden away.

What We Like Most

Good for freshwater and saltwater tanks

It works for aquariums up to 100 gallons in size

Includes 3-stage filtration

Has a valve block for quick release

Easy to set up and maintain

Our Synopsis:

This Marineland product is a good choice if you have a more extensive setup and need something easy but powerful.

Analyst Rating

7

Fluval External Filter

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This Fluval external canister is another excellent option for your fish tank filter. It’s great no matter what type of setup you have - freshwater or saltwater - and it works for aquariums up to 100 gallons. It’ll fit nicely underneath your tank setup, so it’s hidden away from the household. With the quiet motor, it’ll be like it’s not even there. It goes through a three-step filtration process to biologically, mechanically, and chemically filter through your aquarium so your water remains clean, clear, and healthy. It also comes with a clog-proof tray so that if debris builds up, dirty water won’t leak back into the tank. This external canister is easy to set up and maintain, so it’s a great option for beginner fish keepers.

What We Like Most

Good for freshwater and saltwater tanks

Works for aquariums up to 100 gallons

Has a quiet motor

Clog-proof

Includes mechanical, biological, and chemical filtration

Our Synopsis:

This compact external canister filter is a great option for larger aquarium setups.

Analyst Rating

8

Aqua-Tech Power Aquarium Filter with 3-Step Filtration

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Aqua-Tech is another well-known brand in the fishkeeping world. This power filter has two cartridges going at once for a powerful clean. It goes through a three-step filtration process, including chemical, biological, and mechanical filtration to ensure your tank water is clean and healthy. It includes coarse floss, carbon filtration, and a biological grid to provide the best filtration possible. You can use this power filter for freshwater and saltwater setups. It comes in a few different sizes, but this particular product is suitable for aquariums that are about 30-60 gallons. This product will hang on the side of your aquarium wherever you’re able to fit it, and the filtered water will flow back inside the tank. This is another one that’s easy to set up and take care of.

What We Like Most

Good for 30-60 gallons

Includes 3-step filtration

Great for freshwater and saltwater

Easy to set up and clean

Includes a filter cartridge

Our Synopsis:

This power filter is a simple one to set up and maintain if you’re looking for something minimal that will get the job done.

Analyst Rating

9

Tetra Whisper Internal Filter

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This Tetra power filter is another great option for any fish tank. This product comes in a few different sizes, but this particular one is great for aquariums up to 40 gallons. The power filter will clip to the side of your tank internally so that it’s out of the way for a better overall look of the aquarium. This also allows for easy maintenance as well as setup and changing the cartridges. This filter goes through all the filtrations, such as biological, mechanical, and chemical. It will also oxygenate your aquarium. The motor is quiet yet powerful while it works under the water of your tank. The slim design adds a little flair to the overall look.

What We Like Most

Works well for up to 40-gallon tanks

Clips to the side of your tank internally

Whisper-quiet motor

Goes through various filtration and oxygenation

Slim design

Our Synopsis:

This filter from Tetra is a great idea if you need something smaller and simple to maintain.

Analyst Rating

10

Tetra Whisper EX Silent Multi-Stage Power Filter

Read Customer Reviews Here »

This final product from Tetra is another good choice for a few different reasons. It clips onto the back of your aquarium for easy access allowing for a simple setup and maintenance and cleaning. What’s unique about this product is that it comes with a timestrip, which tells you when to change the filter cartridge. Even though the cartridge should be cleaned and rinsed every so often, this will notify you when it needs to be replaced. It goes through various filtrations such as biological, chemical, and mechanical, plus oxygenation. It has a whisper-quiet motor, so you won’t know your filter is there working hard. Even though it looks on the smaller side, this is a powerful filter.

What We Like Most

Suitable for 30-45 gallon tanks

Timestrip included

Has multi-step filtration

Includes oxygenation

Easy to set up and clean

Our Synopsis:

Tetra is a well-known and trusted brand. This product from them is a good choice as it’s easy to set up and clean.

Analyst Rating

Buyer's Guide

At first glance, fish filters look like they’re rotating the water back into the aquarium, and that’s it. However, there’s a lot more to it. When looking for the right fish tank filter for your aquarium, you need to look at the filter type, the filtration process it goes through, and your aquarium’s sizing.

Type of fish tank filter

There are many different kinds of fish tank filters, such as power filters, canisters, under gravel filters, sponge filters, and more. They can also be external or internal filters depending on your needs for your aquarium.

Power filters

These kinds of filters are most likely the ones you see most often in aquariums when you’re at someone else’s house. A power filter can go through multiple filtration steps such as chemical, biological, and mechanical so that your tank gets what it needs to keep the water and your fish healthy. This filter type typically clips onto the edge of your fish tank and hangs outside for easy access for simple setup, maintenance, and cleaning. They come in various sizes depending on how large or small your aquarium is.

Canister filters

Canister filters are more powerful than power filters. They’re in a cylinder shape, which is how they get their name. These are relatively bulky, but they can easily be hidden behind or underneath your aquarium so that it looks like there’s no filter attached at all. Some people prefer this so that their overall aquarium looks neater. On the other hand, some canister filters might sit inside the aquarium either on the side or at the bottom. There’s a lot more upkeep with canister filters, but they perform biological, mechanical, and chemical filtration and sometimes water polishing and oxygenation.

Filtration process

There are a few different filtration processes that happen to keep your aquarium’s water looking clear and clean, as well as keeping your fish happy and healthy. Fish produce ammonia, which is a toxin that needs to be removed from your tank’s water. Biological filtration will do just that through the use of the nitrogen cycle. It will turn the harmful ammonia into good nitrites. Chemical filtration will eliminate any other harmful toxins in the water that isn’t safe, such as metals and other materials, primarily if you use tap water to fill your aquarium. Mechanical filtration will visibly clean the water and purify it from debris such as food waste or leftover food that can quickly dirty the tank water.

Size of your aquarium

Finally, when it comes to searching for the right filters for your fish tank, you need to choose a filter that will filter through the size of your aquarium. No matter what type of filter you decide to buy, it will tell you how powerful it is and what it can handle. These filters will say they’re good for aquariums “up to 100 gallons,” for example. If you have a tank that’s 50 gallons, you need a filter that will handle at least 50 gallons of water.

How do I clean my fish tank filter?

Most filters will come with instructions on how to clean your filter. Every type of filter is different and will require another way of cleaning it. However, these filters usually come with cartridges that you can place inside to help with the filtration process. This is something that you can clean and, eventually, replace once it gets too dirty to clean anymore. One thing to note is that you can rinse these cartridges. It is recommended not to rinse them in tap water to add some harmful toxins back into the tank. Instead, you can rinse it in the bucket of dirty water during your siphoning. This will clean it but keep the bacteria on the cartridge.

How long should I keep my fish filter on for?

Your filter should remain on at all times. Your aquarium needs continuous filtration, and running your filter at all times is the best way to do that. Before adding any fish to your tank, it’s a good idea to run your filter for at least 24 hours so that some good bacteria can build up throughout the filter and the tank’s water for your new friends. Sometimes, your filter may turn off if there’s something wrong with it, or maybe it will seem like it’s not working because it’s clogged. This means you need to clean or figure out how to fix the problem. Worse comes to worst; you may need to buy a new one. However, filters are pretty sturdy and will last you a few years. If the power goes out in your home and the filter doesn’t work for a few hours, it’ll be okay. However, it should always be running.

Can a strong filter kill fish?

This answer is dependent on a few things. This is one reason why looking at the size of your aquarium and choosing an appropriate filter matter. If your aquarium has a filter that’s powerful enough for 100-gallons, but you only have a 30-gallon tank, then it may be too much for your fish. The strong current could harm your fish and, depending on the type of your fish (how big they are), it could kill them. Regardless of how strong of a filter you have, it’s always a good idea to diversify your aquarium with plenty of decor and plants so that your fish have plenty of hiding spaces. Some species like to hide because they may be shy, while others might be scared, or it could be a sign that the current is too strong for them. If this often happens with your fish, check your filter and make sure the current is just right. Alternatively, smaller fish can get sucked up into the tube through the filter. Filters have a grate at the bottom to ensure that this doesn’t happen, but some power filters don’t have this. If you have small fish or even fry inside your tank, keep an eye on them and make sure they don’t stray too close to the filter. On the other hand, you can make a make-shift grate yourself to make sure this won’t happen.

Can my fish survive without a filter?

The short answer is no. All fish need a filter to thrive inside their aquariums. They will survive for some time, but you’ll need to do extra water changes and cleaning. The tank’s overall maintenance will be more in-depth and more often rather than if you had a filter to take care of your fish. Filters go through many different filtration processes. These processes will ensure that you fish and the water remain clean, clear, and healthy. Fish naturally produce toxins that are harmful to them, and, over time, fish waste and leftover food will visibly dirty the tank. Algae will grow on the decor, plants, and the sides as well. A proper filter will ensure that your fish and the tank stay healthy, and the water will be clear. Plus, you’ll only need to clean the filter once in a while instead of deep-cleaning the entire tank more often.

How resonant should my filter be inside the tank?

If you have an external canister filter, then the output should be at least 1.5 to 2 inches deep into the water. This will submerge it enough to siphon through the water it needs to filter through the filter and back into the tank. For the most part, the size of the filter will let you know. For example, if you have a power filter that clips onto the edge of your tank, then it will sit nicely on the aquarium without you needing to adjust it. On the other hand, some filters are entirely submerged inside the tank’s water. Internal filters such as sponge filters, under gravel filters, and even some canister filters will cling to the side or rest on the bottom of your tank. It will depend on the type of filter you buy and how you want the current for your fish to flow.

Expert tip

When cleaning your filter, be sure to avoid any cleaning chemicals and hot water not to kill any good bacteria.

Did you know

A fish filter is equivalent to an air purifier for humans.

Conclusion

Choosing the right fish tank filter for your aquarium doesn’t have to be overwhelming. There’s a lot to think about, but there are many great options for your fish friends.