Best Filters For 20 Gallon Tank 2022 – Reviews & Buyer’s Guide

1. Aqua Clear 2. Aqueon QuietFlow 3. Tetra Whisper


Aquariums, for us, depict vibrancy and show-case worthy objects. Having an entirely different civilization simply at our reach feels enthralling. Don’t know what to do with the empty corner of your house? Buy an aquarium.  

The burning desire to fulfill your kids’ wish for their birthday is solved by getting them an aquarium. It is fascinating, indeed. However, purchasing a tank and filling it with a school of fish, is not the means to an end. When you house a species, you are bound to take responsibility for their well-being. 

The sincerity and love you shower on them will be reflected when you grasp the concept of necessary care. Aquarium care is a delicate arena, where you have to abide by certain conditions and are obliged to settle additional costs. Not unlike our homes, aquariums or terrariums are the home to fish, plants, and turtles, respectively. When we desire to decorate our living space, we ought to revamp their home as well. 


This revamping comes in the form of a couple of tank equipments – like filters, air pumps, pebbles, etc. Such ornaments help in glamorizing the living conditions – boosting the water quality, hygiene and strengthening the functionality of the tanks. 

This article reckons one such essential element required in the tanks- filters- and brings you a painstakingly sorted assortment of the best filter for 20 gallon tank

Through an assiduous attentiveness, you can follow the basics laid down below. These points will help you in making an appropriate choice of the best filter for 20 gallon tank for your fish. 

A sparkling water tank promotes a healthy environment for the organisms to thrive. Both saltwater tanks and freshwater tanks demand ample time and energy for solid maintenance. A filter, in these cases, helps in stress-free caregiving to the tanks. 

From external to internal, these appliances are invented to make your life easier with fewer worries about the wellbeing of your tank. Filters remove toxins like ammonia and nitrates and side by side,  they clean off impurities like large particulates or finer debris. 

The filters, today, are built with advanced technologies that allow the good aerobic bacteria to live. These microorganisms play a key role in keeping the aquatic environment healthy, correspondingly, maximizing the oxygen level of the water for the inhabitants to live. 

Furthermore, the amount of filtration required for your tank will be determined by the size of your tank, the number of inhabitants, as well as your maintenance schemes. 

Now, a tank without a filter might save a few pennies, but it would make your day laborious. Not to forget that even after extensive care, the tank will emit a putrid stench of dirt and endanger the life of the resident species. 

Ergo, filtration is an utmost necessity for the upkeep of the tanks. 

If the search for the latest filtration system is driving you to the wall, this article will bestow an appropriate opportunity for research. It is quite true that you have an assortment of filters to choose from, however, below are some of the best filters for 20 gallon tanks along with their detailed descriptions on characteristics, and pros and cons for you to review. 

Top 10 Best Filters For 20 Gallon Tanks 2022 

1. Aqua Clear – Fish Tank Filter

Aqua Clear best filter for 20 gallon tank AquaClear brings a refiltration system that will save your operating costs and result in superior water quality with the energy-saving pump, Biomax, and activated carbon. 

The patented system of the multi-filter channels ensures the health and safety of some delicate species of fish and plants housing in your aquarium.

One can seldom complain when they get an opportunity to control the flow; and when the AquaClear filter deduces the flow rate as less than 50%, it processes the water inside the filter multiple times, flushing out the impurities, simultaneously, maintaining a healthy and clear tank. 

The Cycle-Guard Multi-Stage filtration system protects your aquarium from getting rid of the beneficial bacteria that might get jetted out when you use a cartridge filter. 

Chancing upon an AquaClear filter will prevent a sudden depletion of bacteria as it requires only one part of the three compartments are changed at a time. Thus, proving itself as one of the best filters for a 20 gallon tank.

On the top, you have the Biomax filter with ceramic rings. The percolation system encourages beneficial bacteria to thrive while keeping the harmful ammonia from polluting the water. The insert has to be replaced every three months. 

In the middle, there is an Activated carbon filter that has the power to absorb impurities, odor, and discoloration. This insert must be replaced every month. 

Lastly, at the bottom, you have the foam insert which should be changed every two months. 

In the box

  • Filter cover
  • Filter case
  • Filter basket
  • Motor
  • Foam
  • Leveling device 
  • Intake tube “U shaped” 
  • Extension tube
  • Activated carbon
  • Biomax
  • Locking clip
  • Mesh bag


  • Weight: 4.5 lbs
  • Color: black
  • Size: 60-110 grams
  • Installation: Quick and easy
  • Filtration Volume: 7x more than other filters
  • Warranty: 2 years
  • Water temperature: 35° celsius
  • Aquarium style: 110 US gallons


  • Hang on the back of filters. 
  • Indoor use. 
  • Nut-free.
  • Clean the power filters every two weeks. 
  • Unplug the power filters before cleaning. 
  • The “U” tube can be cleaned using a brush. 
  • The filter case to be thoroughly rinsed. 


  • The three-stage filtration system gives optimal cleaning- biological, chemical and mechanical. 
  • The Foam insert partakes in debris removal and strives to make a suitable place for the good bacteria. 
  • The 100% premium grade carbon surpasses the one provided in cartridge filters. 
  • It benefits maintaining water clarity in freshwater and saltwater aquariums.
  • It sports a versatile hang-on system. 
  • The design permits more channel volume and proficient water-filter touch. 
  • With a low rate of flow, the recirculation grid passes water multiple times leading to a superior quality of water. 
  • A lifetime warranty for the non-replaceable and undamaged parts is included in your purchase. 


  • Not suitable for sand bottom aquariums. 
  • It makes an obnoxious sound. 
  • Short lifespan. 
  • High maintenance and often leaks water.

2. Aqueon QuietFlow LED PRO Aquarium Power Filters

Aqueon QuietFlow LED PRO Aquarium Power FiltersAqueon, along with its power filter, provides customized filter pads. These are made with such cartridge-like precision that you can chop off the sides to use it in place. 

Besides, it is quite a struggle to clean the filters no matter how hassle-free they claim to be. After their weekly cleaning, what if you forget to power it? 

To simplify your hectic schedules Aqueon came up with a painless solution- Self-priming whereby, the filter starts automatically after interruptions. 

The cartridges possess 25% more carbon than a usual filter. Their patent filter is designed to warrant the rate of water flowing in the channel, increase the level of oxygen content and reduce the noise emitted from the pump. 

In the box

  • 20 power filter 


  • Weight: 1.75 lbs
  • Colour: black 
  • Size: 20-125 GPH
  • Installation: easy
  • Filtration Volume: NA
  • Warranty: lifetime
  • Water temperature: NA
  • Aquarium style: 30 gallons


  • Place a pre-filter sponge over the intake tube to prevent the baby fish from being sucked up. 
  • Shut the filter during feeding time to extend its life. 


  • It only takes 10 minutes to set up and start working. 
  • The LED lights send an alert when to change the filter. 
  • The secondary filtration has three types of systems to choose from. 
  • The cascading effect added with no noise provides a calm picture. 
  • You can replace your cartridge for the filter pad holder for sustainable costing.
  • It boasts of an extremely powerful pump. 


  • The impeller jams with too much grease and stops the inflow of water in the filter. 
  • The unit gets heated up easily. 
  • It is the motor that emanates a rattling noise. 
  • It does not self-prim. 

3. Tetra Whisper In-Tank Filter 

Tetra Whisper In-Tank Filter For more than 50 years Tetra has endeavored to maintain a healthy and hygienic lifestyle for the aquatic civilization. Started as a flake food industry for the fish, today it has successfully expanded into selling racks of aquarium products. 

Their filters are inclusive of a pre-installed bio bag cartridge generating a crystal clear living space for the organisms. Such an In-Tank filter is known for working in silence and gift you with a beautiful waterfall effect. 

Although they go almost 2 inches deep in the water, their performance is heavily equivalent to the hang-on filters. The internal unit facilitates especially for terrariums. 

In the box

  • In-tank filter
  • Bio bag cartridges


  • Weight: 1.5 lbs
  • Colour: black
  • Size: 8 inches 
  • Installation: simple 
  • Filtration Volume: NA
  • Warranty: NA
  • Water temperature: 
  • Aquarium style: 40 gallons


  • For finer cleansing, you can remove the bottom section of the unit. 
  • Either 2 suction cups or a hanger along with one can be installed – depending on the placement. 


  • The in-tank system can stick the filter to the wall of the aquarium, occupying less external space. 
  • The water levels can be adjusted from high to low and vice versa. 
  • It constitutes both an air pump and a filter. 
  • It can also be attached at the bottom, this is particularly useful for terrariums. 
  • The entire pump is set under the water while the lid breaks through the surface of the water. 


  • The filter motor at the bottom poses a threat to the fish. 
  • A tank with a low volume of water will prevent the filter from the suction. 
  • The lightweight lid is quite hard to affix. 
  • Although suction cups are provided, you might have to reattach them with tape after a while. 

4. Tetra Whisper Power Filter 

Tetra Whisper Power Filter Tetra with its incredible track record of aquatic infrastructure is a domestic favorite of every hobbyist and first-timers. Hence, it is not a surprise that they have two phenomenal products lined up in the category of best 20 gallon aquarium filters. 

For healthier dwellings of fish, Tetra brings a 3 in 1 filter ensemble- including the Whisper Power filters with Bio bag cartridges, Whisper Heaters, and Whisper Air pumps. Consequently, such an arrangement is determined to reward you with a flourishing aquarium. 

While the power filters prevent discoloration, putrid odors, and unwanted amenities from polluting the water, the Heaters work hard to keep a stable temperature for the fish to thrive. The Air pumps increase the content of oxygen subsequently, promoting the disintegration of waste by the good bacteria.

Apart from the different parts, the power filter itself works hard to ensure a clean living space. It harbors a double-sided mesh to catch the debris and fish excreta; the ultra activated carbon shields water from discoloring. Aerobic bacteria cultivates with the help of the Bio-foam, thus, repelling ammonia and nitrates. 

In the box

  • Whisper power filter- 3
  • Large bio bag cartridge 


  • Weight: 2.8 lbs
  • Colour: black and gray
  • Size: 330 GPH
  • Installation: hassle-free 
  • Filtration Volume: NA
  • Warranty: NA
  • Water temperature: NA
  • Aquarium style: 30-60 gallons


  • Secure the impeller tightly for proficient performance. 
  • A functional Energizer will shoot magnetic pulls.
  • Follow the troubleshooting steps if your filter stops working-
  • Remove the Magnet Impeller from the filter and clean it off of hair, strings, etc using forceps. 
  • Try to propel the magnet, if incapable, rinse it with cold water. 
  • In case none works, the filter would not start, you have to replace the assembly. 


  • Includes 3 stages of filtration- mechanical, chemical and biological. 
  • Sports a control button to regulate the flow of water into the filter. 
  • The regulator is convenient for turning the filter down during meal times. 
  • Economical and a quiet unit.
  • Affordable.


  • Unreliable motor and filter system. 
  • Short lifespan

5. Tetra Whisper EX Silent Multi-Stage Power Filter 

Tetra Whisper EX Silent Multi-Stage Power Filter This is the third Tetra product, so far, in the list of best filters for 20 gallon tanks. Thus, proving how convenient and loved their filters are. 

This black beauty will give your tank a suave and classy look with its chic design. Those hefty ones portray an additional burden, causing a ripple effect in the radiant tank. 

Such an intuitive system employs activated carbon filters that collect an extensive amount of debris. The water is in a continuous loop of flow which prevents the accumulation of unwanted particles in the filters. 

The Timeslips wielded by the EX45 notifies you to change the carbon filters by blinking red. By pressing tightly on the specific button, they will start working. 

Periodic inflow and outflow of water to and from the filter accrues the quality of water and oxygen content. Accompanying the filter are two cartridge carriers assisting you in cleaning while keeping your hands dry. 

The bio scrubber acts as a string of floss that removes nitrates and ammonia preventing toxicity and discoloration of the water. 

In order to install, attach each part as well as the strainer with the required number of tubes. Make sure the strainer is not in contact with the gravel while it is hung. The water level should be according to the one instructed in the manual. Once in place, you can plug in the unit to commence filtration. 

In the box

  • Whisper EX45 filter
  • 2 Filter cartridge carriers
  • 2 Sets of bio scrubbers


  • Weight: 1 lb
  • Colour: black
  • Size: NA
  • Installation: Quick  and easy setup
  • Warranty: 3 years
  • Filtration Volume: NA
  • Water temperature: NA
  • Aquarium style: 35-40 gallons


  • Lactose-free
  • A user manual is available online for reference. 
  • The instruction videos, also, are available online is helpful in the installation of the filter. 


  • Tetra provides a My Aquarium app, available on iOS, Android and Windows. 
  • The app is an excellent caretaker of your aquarium, sending alerts for a filter change, periodic cleaning, mealtime, water temperature checking, etc. 
  • The regular inflow and outflow of water from the filter to the tank and vice versa keeps augmenting the oxygen content. 
  • It can be used in terrariums as well. The filter can be affixed nearly 4 inches above the minimum water level. 
  • The motor operates quietly. 
  • Affordable and reliable. 


  • Using a sponge filter might slow the rate of flow. 
  • The unit emits an unbearably loud grinding noise when the water level is low. 
  • Short lifespan. 
  • The screen of the filter is not secured properly and can threaten the inhabitants. 

6. Fluval C Power Filter

Fluval C Power FilterA power filter that sports 5 extensive stages of filtration and an indicator to alert during the cleaning period can be considered as one of the best 20 gallon aquarium filters.

The external filter provides 2 biological, 2 mechanical and 1 chemical method of filtration, engineering top-quality performance in maintaining the nutrient content of the water. 

Its filtration system can be manually controlled in order to protect fry, baby turtles and fragile plants. When the filter registers a 50% reduction in the flow rate, the water pulled in and out of it thus, attributing to superior water quality. 

During mechanical filtration, larger unwanted particles stick to the foam surface, and the finer ones are captured by the polyester. They require replacing every 4 to 6 weeks.

The premium-grade carbon, in the chemical filtration stage, absorbs impurities that cause odor, discoloration and need replacing every 4 weeks. 

The biological stage is divided into two parts – in the first half the water inflows into the Bio Screen situated above the Trickle Chamber. This part certifies that the water is evenly distributed in each part of the tank for it to move to the last step. 

Finally, the C nodes warrant optimal water temperature and quality with the help of aerobic bacteria. This stage efficiently rids the tank off of ammonia and nitrates, leaving a healthy environment. 

In the box

  • Filter cover
  • Intake “U” tube
  • Filter case
  • Leveling device
  • Intake tube “telescopic”
  • Bio screen
  • C nodes
  • Impeller cover
  • Chemical basket
  • Mechanical frame
  • Motor unit
  • Activated carbon
  • Seal ring
  • Impeller
  • Biological Trickle Chamber
  • Poly and foam pad


  • Weight: 3.3 lbs
  • Colour: translucent black and red
  • Size: 8x7x4.5 inches
  • Installation: convenient setup
  • Warranty: 3 years
  • Filtration Volume: 264 gallons
  • Water temperature: NA
  • Aquarium style: 40-70 gallons


  • The C nodes are to be replaced in half quantities every six months.
  • Never replace the entire assembly of C nodes altogether. 
  • The bio screen can be changed every 4 months. 


  • The filter is easy to install with its clip-on feature. 
  •  Maintenance is user convenient. 
  • The 5 stages of filtration work to provide crystal clear water. 
  • Not time-consuming, as it maintains a healthy environment itself. 
  • The filter is accompanied by some other ornaments like foam pads, bio screen, carbon, zero carb and ammonia remover- 3 sets each, and C nodes. 


  • Lacks durability. 
  • Poor quality of impeller. 
  • Extremely noisy. 
  • Motor burns out quickly. 
  • Short lifespan. 

7. Penn Plax Cascade Hang-on Aquarium Filter

Penn Plax Cascade Hang-on Aquarium FilterThere is a reason why this hang-on filter is such a score among aquarium fanatics. It is not the cool blue material that illuminates as the water cascades into the tank or the soothing sound of trickling water, but, the confidence Penn Plax assures alongside the product that wins the hearts. 

The manufacturer is a popular brand known for its abundant pet supplies. They have presented the lightest and quietest medium of filtration along with a Bio Falls Quad Filtration System to protect the aquatic milieu. 

Along with a controllable flow rate and tube for intake, the intuitive unit brings in a self-leveling and ready-to-install feature. 

Appropriate for both fresh and saltwater tanks this robust system can be controlled manually as and when required. 

The revolutionary process of Bio Falls Quad includes an internal sponge where aerobic bacteria thrive and work on removing the ammonia and nitrates. Simultaneously, as the activated carbon gets rid of harmful chemicals, odor, and impurities; the poly fiber cartridge captures particles floating around. 

The external feature gives birth to anaerobic bacteria that augments the content of oxygen in the water. 

In the box

  • Hang-on filter
  • 3 units of Cartridges 


  • Weight: 2.05 lbs
  • Colour: translucent blue and black
  • Size: 9x8x5 inches 
  • Installation: Quick  and easy
  • Warranty: 3 years
  • Filtration Volume: 150 gallons
  • Water temperature: NA
  • Aquarium style: 20 gallons


  • Ideal for tanks ranging 35 gallons and less. 


  • There are no cases of leakages. 
  • Steady motor. 
  • Exceptionally quiet. 
  • Affordable. 


  • The filters are thin and made of cheap quality. 
  • Short lifespan. 

8. Aqua-Tech Power Aquarium Filter

Aqua-Tech Power Aquarium FilterAccompanied by a specialized Aqua-Tech  Biological Grid system, this unit gives 3 stages of cleansing. The above-mentioned  system does not need replacing or cleaning due to a unique characteristic of de-clogging itself. 

As available in every filter, the initial stage corporates intense riddance of floating debris and the activated carbon comes in the next stage. It clears the area off impurities and odor.

The latter needs to be replaced every month as the Aqua-Tech cartridges consist of a  fast working carbon system that depletes after continuous usage.

In the box

  • Filter
  • 1 set of Cartridges 


  • Weight: 1.85 lbs
  • Colour: black
  • Size: 40 GPH
  • Installation: effective and hassle-free 
  • Warranty: 2 years
  • Filtration Volume: NA
  • Water temperature: NA
  • Aquarium style: 5 – 60 gallons


  • Prior assembled filter cartridges do not need manual set up. 


  • With 3 stage filtration, the coarse floss erases large floating particles. 
  • The updated design promises a low maintenance unit. 
  • Allows optimal water to filter contacts. 
  • The stainless steel pan is reusable even after the unit stops working. 
  • Prevents untidiness.


  • Extremely loud. 
  • The rate of water flow lowers down with use. 
  • Short lifespan. 
  • The pump is unreliable. 

9. Marina Power Filter

Marina Power FilterAmong the best 20 gallon aquarium filters, a power filter like that of Marina occupies a special place. A translucent filter unit that permits the user to note the necessity of replacement. 

Designed to look attractive, this sleek self-priming system also provides the tank with practical advantage. Made with the best interest in maintenance, it is equally simple and convenient to clean. 

Both the cartridges contain Ceramitek. These are high-quality porous media made of ceramic that gives an enhanced biological filtration for better aquatic functioning. 

In the box

  • Filter
  • Bio carb cartridge 
  • Bio clear cartridge 


  • Weight: 1.23 lbs
  • Colour: monochrome, translucent 
  • Size: 10 GPH
  • Installation: hassle-free 
  • Warranty: as labeled
  • Filtration Volume: NA
  • Water temperature: NA
  • Aquarium style: up to 10 gallons


  • Through adjustable flow buttons, one can manually control the rate of flow. 
  • The motor should be submerged under the water. 


  • Takes less tank space, unlike other filters. 
  • The self-priming unit only requires to be plugged into work. 
  • The motor is supposed to be quieter than others. 
  • You can fit 4 cartridges in the filter, together. 
  • Energy-efficient. 


  • Filter cartridges are thin. 
  • The adjustable height is questionable. 
  • Unreliable pump. 
  • Vibrates with prolonged use. 
  • Short lifespan. 

10. Marineland Magniflow Canister Filter

Marineland Magniflow Canister FilterOne of the favorite brands of hobbyists, Marineland claims to have brought refreshments among the aquatic products and in their environment. 

Their comprehensive skills toward the marine flora and fauna extend over to the myriad equipment they have manufactured over the years. 

Among such phenomenal innovations, is their very popular 360 Canister filter. You can say this filter was designed as synonymous to convenience – with a firmly secured lid yet can be easily removed. 

The filter trays (Stack N’ Flo) push the water through the three stages of filtration – mechanical, chemical and biological – chronologically. Moreover, the self-priming procedure starts once the unit is filled with water. At the same time, a valve is shut down, automatically, to ensure a leakage-free work. 

Incorporating a multi-stage filtration system is quite a feat for the ruby-yeared fishkeepers. Bio Spira is encouraged to grow under the protection of the Biofilter Balls and rings made of ceramic. 

The filter also boasts of a vivid LED lighting system in varied ranges from 18″ to 60″. They have a comparatively longer life than a usual bulb and can produce a natural effect of both sun and moon. 

With a unique design and features that separate this fellow from the others, it can be termed as the best filter for a 20 gallon tank.

In the box

  • Canister filter 


  • Weight: 19.6 lbs
  • Colour: black
  • Size: 100 GPH
  • Installation: convenient and quick
  • Warranty: 3 years
  • Filtration Volume: 360 gallons
  • Water temperature: NA 
  • Aquarium style: 100 gallons 


  • Remove the polishing pad every 3 weeks. 
  • Remove the carbon every week. 
  • Replace the filter foam pads every 9 weeks. 
  • Clean the filter pads every 3 weeks
  • Do not use soap to clean the foam pads. 


  • The tight seal warrants easy removal of the top lid for accessing. 
  • A filter pad can be used as a water polisher to exterminate the debris. 
  • Marineland sports a Black Diamond activated carbon that cleanses the tank off odor and impurities. 
  • Suitable for both salt and freshwater tanks. 
  • Consisting of user-friendly quick-prime and valve-block features. 
  • T shaped cartridges.


  • Bubble formulation in the tube. 
  • Frequent leakages. 
  • Short lifespan. 

Best 20 Gallon Aquarium Filters: What’s Your Pick?

Aquatic civilization is as important as that of mankind. They contribute to a mammoth-sized function in the ecosystem. With the forthcoming environmental hazards, organizations have commenced spreading awareness as well as finding resources to protect them. 

As a part of this world, we too can contribute to their healthier lifestyle. You might consider them as trivial, however, a little kindness never harms. Working to keep them safe and sound will result in good health and a positive attitude towards life. 

After all, you too are participating in the scheme of a greater good. 

Harboring a fish tank comes with responsibilities and providing them with fresh oxygen and a clean home is your priority. Thus, the best filter for 20 gallon tank list is a convenient and economical manner of ensuring a blossoming aquatic life at home.

Hasty decisions never work efficiently. If you are willing to give the little organisms a home,

sincerity always takes the cake. Additionally purchasing the best 20 gallon aquarium filter will help you in the long run- free of mess and burdens regarding your pocket.

Hopefully, this article will help you in selecting the best filter for your 20 gallon tank!