Filter For 20 Gallon Fish Tank Reviews

Best Filter For 20 Gallon Fish Tank

An aquarium is great as it gives more beauty to your life and space. However, for really enjoy it, you need to have the right types of equipment for the tank itself.

Choosing the right tank and the best filtration system are some of the parts you need to take care of. You also need to get the right pumps and thermometers and all the other accessories that help getting the best out of an aquarium.

Which filter is the best?

There are several types of filters and you need to decide which one is the best option for your needs and wallet.

If you’re a beginner, an under gravel filter is a great option as it’s efficient and cheap. It does clog and time, but it’s maintenance free, which may be a selling point for many.

The box filter is the cheapest option that you could go for. It works better for a tank smaller than 10 gallons and its efficiency isn’t the greatest.

The most popular option is the power filter that offers chemical, biological and mechanical filtration. Additionally, it’s easy to set it up, to maintain and to use and its price is rather low.

If your tank is large, you should go with a canister filter that is placed under the tank, letting you enjoy the view. It requires more attention from you and you may have to pay the extra buck for it.

The trickle filter doesn’t come cheap and it’s addressing the saltwater tank. It gives biological filtration but versatility isn’t its strength.

How to choose?

You need to take a good look at your tank and your wallet at the same time. If free time isn’t something that you have, it’s wiser not to get a filter that needs constant maintenance.

The options are plenty and the price range fits all budgets out there, so it’s only up to which one is your final choice.

TOP 5 Filter For 20 Gallon Fish Tank Reviews

1). Whisper In-Tank Filter for aquariums

Whenever you go shopping on a tight budget, the Whisper In-Tank Filter with BioScrubber for aquariums is a valid option to try.

The filter is made for the use in aquariums up to 20-gallons and needs large Bio-Bag filter cartridges. The setup is easy and you can also install it with a hanger and a suction cup. However, some are going to use two suction cups, according to the placement of the filter.

Easy to access too, the filter only needs a couple of minutes to clear the water. The water flow is strong enough to circulate the whole tank and the filter runs pretty quiet too.

You may use the filter for both aquariums and terrariums and cleaning it shouldn’t be a problem either. You simply remove the bottom to get to the impeller for a thorough cleaning.

The filter is going to work in as little as 2 inches of water so it’s a great choice for the turtle tanks.

We also like the filter because it’s easy to adjust it too high or low water levels with the mounting suction cups or the bracket.

The filter is nice and clear and keeps the water clean for 1 week. It gives space to your tank and it’s so easy to find it in stores.


  • It’s easy to use and to set it up
  • It comes with a hanger and suction cup
  • It runs quiet and the water flow is strong
  • It cleans the water rather fast


  • It doesn’t come with a lit
  • Some don’t go for its mounting system

As long as you’re focusing on the goods, the filter isn’t an option to skip on when shopping as it’s good value for the buck you’re paying.


2). Aqueon QuietFlow LED PRO Aquarium

One of the most popular choices out there, the Aqueon QuietFlow LED PRO Aquarium Power Filters is checking many boxes when it comes to overall value and price.

The most important part about the filter is that it offers mechanical, chemical and biological filtration altogether. Additionally, it also gives assistance with the Aqueon specialty filter pads.

Another important feature on the filter is that it’s self-priming so it starts up automatically once the cleaning is done. This feature is also used in case of power interruptions.

The filter ensures flow rated that sustain proper water circulation, helping your fish maintain their health.

Going farther with the details, we also like the LED indicator light that flashes whenever it’s time for you to replace the clogged cartridges. The filter is able to monitor the actual water levels. On the side note, the filter inserts clog pretty fast which is kind of a bummer.

The internal pump of the filter is powerful and helps with minimizing the noise, while eliminating leaks. However, the water runs pretty loud which is why many think the filter is on the noisy side.

The filter improves water quality and clarity, increasing the oxygen levels and keeping down the noise level.

The setup is easy and the filter is pretty easy to take care of too.


  • The filter offers mechanical, chemical and biological filtration
  • It comes with Aqueon specialty filter pads
  • It’s easy to install and to take care of
  • It’s packed with many good features


  • The water gets noisy from the powerful pump
  • The filters could be better

All things considered, the filter offers many good things for your fish tank and it’s money well spent most of the time.


3). AquaClear Power Filter

Easy to set it up and to use it, the AquaClear Power Filter is one popular filter you shouldn’t skip on whenever in need.

The refiltration system gives higher contact time with filter media, whereas its energy pump is efficient and lowers the operating costs.

The filter works fast and comes with many good things. Its volume is big and it comes equipped with Aqua Clear Foam, Activated Carbon, BioMax and Cycle Guard. This is why the filter is able to provide continuous biological filtration for higher water quality.

Versatile, the filter is a hang-on model and works really well.  Its patented Re-Filtration System lets you easily control the flow rate, without minimizing its efficiency. Once the flow rate is lowered, almost 50% of the water within the filter chamber is going to be processed several times.

The filter comes with Cycle Guard Multi Stage Filtration System which means it offers mechanical, chemical and biological filtration altogether. Any healthy aquarium needs “beneficial” bacteria that are great for removing the toxic ammonia and nitrite.

Easy to clean, the filter moves a lot of water and may be used for saltwater filtration too. It’s rather quiet and clears your tank pretty fast too.


  • It offers chemical, mechanical and biological filtration
  • It runs quiet and moves a lot of water
  • It’s easy to set it up, to use and to clean
  • You may adjust the water flow


  • It’s simple and doesn’t come with many features
  • You need to buy all the components

However, as it’s versatile, dependable and easy to use, the filter is a great choice option for many and quite a bang for your buck.


4). EHEIM Classic External Canister Filter

Quiet and dependable, the EHEIM Classic External Canister Filter with Media is a filter that is going to satisfy many, due to its quality and features.

The filter comes with permo-elastic silicon sealing ring that is placed on the pump head. This way, it’s easier and safer to close it after your cleaned it.

The maximum flow rate is 40US Gal and the filter runs very quiet. It’s equipped with filter sponge and/or loose filter media. It also comes with filter media and valves and you can get the best out of it with its accessories (filter basket, inlet pipe, spray bar, hose and installation accessories).

The filter gives a mechanical and biological purification in just one process thanks to the constant water circulation and simultaneous oxygen intake.

You can safely install the filter under cabinet, without having to drill any holes. The setup is fairly easy, but it does require some handy work.

The filter is well made and has a durability feel to it. It’s well made and the design is well thought-out. Priming is easy and it’s not complicated at all to clean the filter.


  • It’s well made and has a good design
  • It comes with accessories
  • It’s quiet and efficient
  • It provides mechanical and biological filtration


  • The instructions are useless to many
  • Some experienced leakage

Regardless of the minor issues, the filter is a product to take under consideration as it’s dependable, long lasting and efficient.


5). Fluval External Filter

Sturdy and well built, the Fluval External Filter is a great investment to make and it’s not only durability that it brings to the table, but also efficiency and high value.

The filter presents a multi-stage filtration system that works for both fresh and saltwater aquariums. You can use it for aquariums up to 25 gallons.

Let’s take a closer look at the features of the filter. For instance, the multi-stage filtration means that each filtration stage is placed differently to give higher versatility, with minor maintenance. The system uses the whole canister volume for increasing the filtration efficiency.

The filter has a large capacity and the vertical twin foam pre-filters suck a good amount of debris, minimizing risk for clogged media.

As for the chemical and biological stages, it’s good to know that the filter comes with independent modules that let you clean fast and easy the media.

The filter also features AquaStop valves that stop water flow with no risk for disconnecting the hoses, or for mess and elimination leaks.

The list of features doesn’t stop here and the filter comes with lift lock clamps that keep motor housing in place. The class fibers give durability and strength to the filter too.

The filter comes with a clog-proof intake strainer and dual layer foam screen. It has a well thought design that dampens noise. The motor is strong and long lasting and the filtering runs pretty quiet.

The flow rate is high, but the vibration is minimal and the hoses are semi-transparent.

On top of everything else, you only need to clean the filter every 5-6 months a year.


  • The filter comes with a multi-stage filtration system
  • It has a strong motor that runs quiet
  • The flow is high, but the vibration is minimal
  • The filter is packed with many good features


  • Some think the hoses could be longer
  • Installing it isn’t as easy as you’d expect

All things considered, the filter is quite a power-horse in its category and, at the end of the day, is a wise investment to make for your pets.

For instant start-up without the need for manual siphoning.


Best aquarium filter for 20-gallon tank

Affordable and reliable most of the time, the Tetra Whisper Power Filter for Aquariums brings many good things to the table and its inherent flaws shouldn’t change your mind.

The filter is made for the smaller aquariums up to 20-gallons and you should use it with large Whisper Bio-Bag cartridges.

The system is well thought-out and there are in fact three filters that work together, maintaining your aquarium clear and clean for longer time.

The filters com with charcoal and sponge filters so the filter is able to set the biological colonies, while minimizing ammonia.

The adjustability of the filter is a good feature to mention and you may easily set up the flow by using the dial on top. The flow goes from full to almost off.

The filter has a good build and it’s well made. Its replacement filters are both easy to find and quite cheap too.

Quiet and pretty strong, the filter is a valid option to consider for your aquarium.


  • It features 3 filters that keep the aquarium clean and fresh
  • It’s well made and has a good build
  • It uses large Whisper Bio-Bag cartridges
  • It’s strong and quiet


  • There’s no indicator to tell you when you need to change the filters
  • Some doubt its durability

However, for the money you’re paying, the filter keeps your aquarium clean and clear for a good amount of time and is so affordable too.


Best canister filter for 20-gallon tank

The swimming pool style rotating valves on the Penn Plax Cascade Canister Aquarium Filter are one thing to explain its efficiency, but the filter comes with many other good features attached to it.

The filter is made for aquariums up to 30 gallons and its valves come with flow controls. It features push button primer that allows easy and fast setup. The filter comes with two independent 360degree rotating taps and the flow rate shut-off valves let you adjust the flow.

We also notice 2 large media baskets that you can easily customize according to your needs. When taking care of the filter, the flow valves are easy to remove. The hoses, input and output don’t need to be removed while cleaning the filter.

The stackable media trays are large so it’s easy to have multi-stage filtration. The filter features a rubber mounter tip-proof base that is sturdy and keeps the filter in place.

Let’s not forget to mention the air-tight seal that ensures good flow rate, in a very quiet manner. The clamps are easy to lift and releasing the vacuum is easy. Removing the top is easy peasy too. You may suspend waste matter thanks to the directional returns.

On top of everything else, the filer comes in a pretty cobalt blue color that matches many aquarium setups.


  • The filter comes with large filter trays
  • It’s packed up with plenty of good features
  • It’s easy to set it up and to use
  • It looks very nice


  • It has no marks for input/output hoses
  • Some reported the hoses kink at times

Long story short, the filter is a great canister filter that is going to keep your fish tank clean and clear for quite some time.


Best hob filter for 20-gallon tank

Giving a certified flow of 100GPH, the Marineland Penguin Power Filter w/ Multi-Stage Filtration is a great option for the aquariums up to 20-gallon. It needs the Rite-Size A” filter cartridge.

The filter offers easy three stage filtration: mechanical, chemical and biological. It comes ready to use with every filter and it removes waste, discoloration and odors both mechanically and chemically.

The mechanical filtration searches for dirt and debris, using the patented ribbed back for increased water to carbon contact. The Black Diamond Premium Activated carbon is efficient for cleaning the tank from odors, impurities and discoloration.

As for the biological filtration, it’s the special Bio-Wheel that does that for the filter. It’s able to remove toxic ammonia and nitrite so that your filter remains nice and clean for long. The Bio-Wheel comes with 50% more surface area, which is a plus.

Going through the features, we notice the two-piece vented cover that allows easy access to the filter cartridge. Additionally, it brings down the noise of the filter too.

The filter also features an adjustable mid-level intake that attaches to the intake tube, increasing the water circulation.

Easy to fix and to clean, the filter is a great as a hob option.


  • The filter offers three stage filtration system
  • It’s easy to use and to set it up
  • It has many good features
  • It’s quiet and easy to take care of


  • The filters are a tad pricey
  • Some noted an inconsistent performance

Nevertheless, the hob filter does a great job for keeping the aquarium nice and clean and isn’t pricey at all.


Best filter for 20 gallon planted tank

Able to clean aquariums up to 20 gallons, the Marina Power Filter isn’t the most powerful filter out there, but it sure manages to keep your planted tank nice and clean for quite some time.

The filter is easy to set it up and to take care of. It’s a self-priming filter that runs rather quiet.

Among many things, we also like the adjustable flow on the filter. The filter is compact and has a slim design, offering more space behind your planted tank.

The motor is submerged in the tank so the operation is quiet. The start-up is easy as you don’t need to prime it. The filter is ready to use right after you plug it in.

The filter comes with 4 filter cartridges: 2 Bio-Carb and 2 Bio-Clear. Each of the cartridges includes Ceramitek which improves the biological filtration.

The media is easy to replace and the flow isn’t the most powerful, but it’s deep and quiet. The spreading of water is good and the filter is an economical and dependable option for your planted tank.


  • It’s easy to set it up and to use
  • It’s self-priming
  • The motor is submersed so the filter runs quiet
  • It’s compact and has a slim design


  • The sponge could be better
  • The lid is a tad narrow so it can rattle at times

In a nutshell, the filter is a valid choice for the planted tank as it’s fairly priced and efficient at the same time.


Best power filter for 20-gallon tank

Equipped with a highly efficient filtration system, the Fluval C Power Filter is quite a power horse among the power filters.

The filter comes with ceramic heater core which ensures even and efficient heat distribution. It filters up to 119GPH and comes with a cleaning indicator that tells you when it’s time to rinse the polyfoam.

Easy to set it up, the filter is a clip-on model that is easy to use and to take care as well.

Going through the details, we notice the poly/foam pad that delivers mechanical filtration. The pad has a large area and performs two stages of the mechanical filtration. The first stage of the foam catches the large particles, whereas the second stage of the dense polyester gets the fine debris.

The activated carbon insert is responsible for the chemical filtration and is made with 100% premium research grade carbon. It has a large surface area that absorbs efficiently the impurities. The carbon filter insert also eliminates the unpleasant odors, impurities and discoloration, giving your aquarium a crystal clear water.

The additional hydraulic circuit takes care of the biological filtration as it takes part of the intake water to the Bio-Screen from the top of the Trickle Chamber cover. The Bio-screen eliminates debris before it gets to the biological chamber, making sure that the water pumped to the Trickle Chamber is spread nice and easy on all areas, before dripping on the C-nodes.

The surface of the C-nodes contains complex pore system that offers good living space for the “good” bacteria that removes ammonia and nitrites. The “Star Shape” gives bigger filtration surface and more biological power, keeping the tank healthy.

Compact and easy to use, the filter has a great build and it’s worth every single penny.


  • It’s easy to set it up and to take care of
  • It offers mechanical, chemical and biological filtration
  • It keeps the water crystal clear
  • It’s compact and has a good build


  • Some think it sits on the loud side
  • The bio media basket could be bigger

All things considered, for its high efficiency and power, the filter is a sure buy whenever in need.

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