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10 Best Aquarium Filters: HOB, Canister, Undergravel & Internal

Best Aquarium Filter

Whether you own a big or a small fish tank, you must take care of the livestock inside and this mostly involves filtration, which ensures all the mess is quickly removed from the tank before it causes harm.

This process also gets rid of any excess food that causes cloudiness in the water and also reduces or even eliminates algae growth.

Because of this, it is important to get the best aquarium filter, and this article looks at some of the best ones in the market so as to make it easier for you to select the best product for your tank.

You can also read other product revies such as HOB filtercanister filterfilter for turtle tankaquarium pump.

Product Name




Current Price

1. Aqua Clear HOB Filter

Aqua Clear HOB Filter

HOB aquarium filter with a large filtration media volume and a cycle guard system for maintaining beneficial bacteria in the system


2. Penn Plax Canister Filter

Penn Plax Cascade Canister Aquarium Filter

Very large canister filter with 5 media baskets and 360º rotating flow valves


3. Fluval External Aquarium Filter

Fluval External Aquarium Filter

Aesthetically good-looking canister filter that holds 35 - 50% more water and operates very quietly


4. Marineland 400B Emperor Aquarium Filter

Marineland 400B Pro Series HOB Filter

Powerful 400 GPH HOB filter with a 3-stage filtration system comprising of very effective twin bio-wheels for biological filtration


5. Penn Plax Undergravel Aquarium Filter

Penn Plax Undergravel Aquarium Filter

Affordable under-gravel aquarium filter with a 2-stage filtration system and large 1-inch lift tubes connected to the hidden filter plates


6. Polar Aurora External Canister Filter

Polar Aurora External Canister Filter

Self-priming external canister filter with a 4-stage filtration system and a fast flow rate of 525 GPH


7. Eheim Classic External Canister Filter

Eheim Classic External Canister Filter

Green-walled translucent canister filter with a bottom-placed input valve, a top output valve and a permo-elastic silicon sealing ring for preventing leakages


8. Marineland Penguin Power Filter

Marineland Penguin Power Filter

Affordable HOB filter with a two-piece vented cover for easy maintenance and twin bio-wheels for superior biological filtration


9. Penn Plax Cascade Hang-on Aquarium Filter

Penn Plax Cascade Hang-on Aquarium Filter

Intuitively-featured HOB filter with a self-leveling system, adjustable flow control, and adjustable intake tube


10. Tetra Whisper In-Tank Filter with BioScrubber

Tetra Whisper In-Tank Filter with BioScrubber

Very affordable in-tank filter with a bio-scrubber for biological filtration that is very easy to maintain


1. Aqua Clear A620A1Best Overall Aquarium Filters

Aqua Clear HOB Filter
  • Available for: 60 – 100 gallons
  • Flow rate: 500 GPH
  • Filter system: 3 stage

Aqua Clear’s HOB filter takes the overall best position spot because it has a bit of everything.

For starters, being a hang on back filter means that it is very easy to install and maintain. The product is also quite small and lightweight and this makes it easy to manage, for instance when uninstalling it so as to clean the tank.

The unit has a 3-stage filtration system that allows up to 6 times more filter media volume to fit inside and this exposes the water to a larger surface area for filtration.

Additionally, a water flow control feature reduces the flow rate by up to 50%, giving the water a long time to make contact with the filtration media for cleaner results.

For retaining beneficial bacteria on the inside, this HOB filter features a cycle guard system, which basically means that only one of the three filtration media should be replaced at a time in the following order:

  • Carbon filter every month.
  • Foam filter every two months.
  • Biomax filter every three months.

This ensures that a portion of these bacteria is left in the other media so as to easily grow and recolonize the system, making it the best HOB aquarium filter.

On the downside, the unit requires priming on every restart but once this is done, it functions very smoothly.


  • Easy to install and maintain
  • 3 stage filtration system
  • Large filtration media volume
  • Adjustable water-flow control
  • Cycle guard system for retaining beneficial bacteria in the filtration media


  • Requires priming
  • Large filter media volume means that it requires a lot of media for replacement

2. Penn Plax CCF5ULVery Effective Canister Filter

Penn Plax Cascade Canister Aquarium Filter
  • Available for: Up to 200 gallons
  • Flow rate: 350 GPH
  • Filter system: 3 stage

On first look, Penn Plax’s canister filter is a very large unit but this is used as an advantage to its filtration process. The large body means that it houses 5 large media baskets, which can carry a lot of filtration media for a very effective water purification process.

With these media baskets, the unit can accommodate floss pads, activated carbon and ceramic rings to carry out mechanical, chemical and biological filtration for a complete 3 stage filtration process.

On the upper side, this filter features two state-of-the-art flow valves, which can rotate 360º independently for worry-free placement in the tightest of aquarium cabinets.

Additionally, these valves have swimming-pool-like hose clamps for adjusting the flow rate, giving you more control over the filtration process.

If this canister is too big for you, Penn Plax offers 4 smaller sizes, which include up to 30, 65, 100- and 150-gallon options, with slower flow rates and at a more affordable price for the smaller tanks.

However, regardless of the size, each filter requires priming on first use but this process is simplified using an easy push button primer.   


  • Comes with 5 large media baskets
  • Can accommodate all the required filter media for a complete 3 stage filtration process
  • 360º rotating valves
  • Adjustable flow control
  • Available in 5 different sizes for differently-sized tanks


  • Requires priming
  • Very big in size

3. Fluval A217Beauty Meets Power

Fluval External Aquarium Filter
  • Available for: Up to 100 gallons
  • Flow rate: 383 GPH
  • Filter system: 3 stage

If looks are the main thing to consider, then this is the best aquarium canister filter because it has a very simple yet sleek look from the outside.

This, however, should not fool you into thinking that it's all looks and no power. The filter has a powerful pump that circulates the water at a top speed of 383 GPH and features a vibration-dampening impeller bearing and sound cover, which makes it operate very silently.

Back to its looks, not only does its squarish shape improve its aesthetic appearance, but it also makes the unit hold 35 to 50% more water than round canisters of a similar size. This gives a better water flow inside while also increasing the surface area for the purification process.

For this purification process, the unit features a multi-stage filtration system comprising of mechanical, chemical and biological filters. These stages are separated from each other and this results in minimal maintenance plus an optimization in the filtration efficiency.

On the downside, the filter is quite expensive and its valves are fixed in one position, which means that it might be challenging to fix it in tight aquarium cabinets.

However, they are fixed facing vertically upwards, which is an easier position to deal with as compared to other placements.  


  • Aesthetically good looking
  • Operates very quietly
  • Holds 35 - 50% more water than round canisters
  • 3 stage filtration system
  • Separated filtration stages optimize its efficiency while also minimizing the frequency of maintenance


  • Expensive
  • Valves do not rotate

4. Marineland 400BA Revolutionary HOB Filter with a Powerful Filtration System

Marineland 400B Pro Series HOB Filter
  • Available for: Up to 80 gallons
  • Flow rate: 400 GPH
  • Filter system: 3 stage

Marineland's 400B is a bio-wheel powered hang on back filter that is very easy to maintain, yet it carries out a very thorough cleaning process.

This is because bio-wheels are a revolutionary technology in providing wet or dry biological filtration because they support heavy bacteria growth. Despite this, they can be retained for a very long time because they never get clogged.

To make matters even better, the 400B features 2 bio-wheels, which provide better filtration by having a larger surface area for growing the beneficial bacteria required to break down ammonia and nitrites from the fish’s waste. This makes it one of the best filters for fish tanks.

Apart from these two, this unit has filter cartridges for providing mechanical and chemical filtration and this completes the 3-stage purification process.  

The other benefit of having bio-wheels is they help splash the water around the filter as they rotate and this simple action assists in aerating the water. Coupled with the waterfall that it creates as the water exits, this unit doubles up as an air pump of sorts.

However, the filter’s water flow rate is not adjustable and it requires priming on every restart. The features described above though, make it worth considering.


  • 3 stage filtration system
  • Two bio-wheels for more effective biological filtration
  • Easy to maintain
  • Aerates the water.
  • The powerful pump delivers a 400 GPH flow rate


  • The flow rate is not adjustable
  • Requires priming on every restart

5. Penn Plax CFU55The Invincible Filter

Penn Plax Undergravel Aquarium Filter
  • Available for: 40 – 50 gallons
  • Flow rate: N/A
  • Filter system: 2 stage

Penn Plax’s under-gravel filter consists of 4 square filter plates, each measuring 11.5 inches in length and width. These plates are designed to securely interlock together to form a tight unit that pulls the water while placed below the gravel.

This means that the filter is hidden from view, leaving you with a fish tank whose aesthetics are not interrupted by protruding or external filters. All you have to do is attach an external air pump and you are good to go.

For circulation, this setup comes with 2 large 1-inch lift tubes and a pair of air stones, which are connected to the external air pump to create the air and water flow inside these tubes.

The result of this is water being pulled through the filter from under the substrate, and this utilizes the gravel as a biological filter. Two Filt-A-Carb cartridges are also included in the package and these help in chemical filtration by absorbing bad odor and water discoloration.

Although the unit lacks a mechanical filter, it is very affordable and thus, you get what you paid for.


  • Affordable
  • A majority of the filter remains hidden below the gravel
  • Comes with a pair of air stones and a pair of chemical filtration cartridges
  • 2 large 1-inch lift tubes for housing the air stones


  • Lacks a mechanical filter
  • Requires an additional air pump

6. Polar Aurora 525 GPHBest Filters for Controlling Algae/ Bacteria

Polar Aurora 3-stage External Canister Filter (370 GPH)
  • Available for: Up to 200 gallons
  • Flow rate: 525 GPH
  • Filter system: 4 stage

Polar Aurora’s external canister unit is a top-rated aquarium filter because, apart from having a set of 4 media trays for housing mechanical, chemical and biological filtration media, it has a 9-watt UV sterilizer that helps to kill algae and bacteria, resulting in very clear waters.

Additionally, the unit has a very powerful 55-watt pump that delivers a flow rate of 525 GPH, which is very good for turning over a big volume of water. This makes it ideal for aquariums of up to 200 gallons in capacity.

Despite this power, the pump has a low noise design, which means the canister operates very silently, making it very comfortable to use in the home.

The pump also has a self-priming mechanism, which makes it very convenient to use because you won’t need to siphon the water manually before starting it.

On the downside, the unit does not have a flow control feature and its valves are fixed in one position.


  • 4 stage filtration system
  • 9-watt UV light for killing bacteria/ algae
  • Powerful 55-watt pump that gives the unit a flow rate of 525 GPH
  • Low noise design
  • Self-priming mechanism


  • The flow rate is not adjustable
  • Non-rotating valves

7. Eheim 2213371Still One of the Best Canister Filters

Eheim Classic External Canister Filter with Media
  • Available for: Up to 66 gallons
  • Flow rate: 116 GPH
  • Filter system: 3 stage

Eheim Classic’s canister filter has a rounded design with a translucent green wall that makes it possible to monitor the status of the filtration media without opening it up.

The most unique thing about this unit though is its input and output valves. Although the flow rate is not adjustable through these openings, the input valve is placed close to the bottom of the canister while the output valve is placed at the top.

This design ensures that the water pulled from the aquarium passes through all the filter media before exiting at the top. However, the unit requires priming before use so that it’s built-in pump can proceed to pull the water through the media at a flow rate of 116 GPH.

To prevent any leakages, the pump head is fitted with a permo-elastic silicon sealing ring, which also makes it easy and safe to reassemble the head to the canister after cleaning.

A wide range of accessories is included in this package. These are Eheim’s Mech and Substrat Pro filter media, a spray bar, an inlet pipe, a hose, suction cups, and other installation accessories.


  • Translucent wall makes it possible to easily monitor the status of the filtration media
  • Bottom intake and a top outlet ensure all the water passes through the filter media
  • Permo-elastic silicon sealing ring for preventing leakages on the pump head
  • Comes with a wide range of accessories


  • The flow rate is not adjustable
  • Not self-priming

8. Marineland PF0350BEasy to Maintain HOB Filter

Marineland Penguin Power Filter
  • Available for: 50 – 70 gallons
  • Flow rate: 350 GPH
  • Filter system: 3 stage

Marineland's Penguin power filter is one of the best freshwater aquarium filters because it features a bio-wheel technology, which is proven as the best system for removing toxic nitrites and ammonia from water during the biological filtration process.

However, the filter is not limited to freshwater use. Combined with its rite size floss cartridge for mechanical filtration and activated carbon for chemical filtration, this 3-stage system is also capable of handling saltwater aquariums, making the Penguin a very versatile filter.

Maintenance is always an easy task when dealing with HOB filters and this one is no different.

The unit has a two-piece vented cover that is easy to remove so as to access the filter cartridges for replacement or cleaning purposes. The cover also makes it operate silently because it acts as a noise silencer. 

Apart from this, an adjustable mid-level intake leads to improved water circulation because it distributes the water from the center of the filter to its twin bio-wheels on each side.

The disadvantage with this filter is that it requires manual priming on every restart and does not have an adjustable flow rate. However, it is very affordable and therefore, you get what you paid for.


  • Twin bio-wheels for the best biological filtration process
  • Rite size floss cartridge and activated carbon for a complete 3 stage filtration system
  • Easy to maintain
  • Adjustable mid-level intake improves its internal water circulation
  • Affordable


  • Requires a cup or two for priming before starting
  • The flow rate is not adjustable

9. Penn Plax CPF5Intuitively Featured HOB Aquarium Filter

Penn Plax Cascade HOB Filter
  • Available for: 55 – 100 gallons
  • Flow rate: 300 GPH
  • Filter system: 3 stage

The Cascade hang-on-back filter from Penn Plax is also a very affordable unit and yet it has some very impressive and intuitive features, which include a self-leveling system that keeps the unit level when hung on all types of aquariums.

An adjustable flow control feature is also incorporated into this filter’s design, and this is simply adjusted by a knob, giving you more control over the filtration speed and process.

On the intake, a lengthwise adjustable tube is used and this makes it possible to place the strainer close to the bottom of the tank so as to suck water from the bottom level.

If the 55 – 100-gallon filter is too big for your tank, there are smaller sizes that include an up to 7-gallon, 1.5 – 10-gallon, 10 – 20-gallon, 20 – 35 gallon and 35 – 55-gallon options for differently-sized tanks.

However, all of them have a 3-stage filtration system and require to be primed before being started.


  • Affordable
  • Self-leveling system
  • Adjustable flow control
  • Adjustable intake tube
  • Available in 6 different sizes


  • Needs to be primed before use

10. Tetra 25816Best Aquarium Filters for the Money

Tetra Whisper In-Tank Filter with BioScrubber
  • Available for: Up to 10 gallons
  • Flow rate: 80 GPH
  • Filter system: 3 stage

Tetra is a well know brand in the aquarium filter segment for making high quality, affordable units and this in-tank model is no different.

In fact, it is the most affordable one in this review and yet, it is a quality filter that runs very silently because the motor operates underwater.

However, this also means that it occupies some space inside the tank and this reduces the overall volume available for your fish. The good thing though is that it makes it possible to place the tank flush against the wall for a good fit, especially on your wall corners.

Additionally, the filter can be used in as little as 2 inches of water, which makes it ideal for fish as well as turtle tanks, and it tops this off by creating a waterfall inside the tank for better aeration.

In terms of filtration, this unit features a 3-stage cleaning system, with the biological filtration being carried out by a bio-scrubber. This bio-scrubber has anti-clog design, which drastically reduces the effort required for maintenance.


  • Affordable
  • Runs very quietly
  • In-tank filter means that it can be placed flush against the wall
  • Can operate in as little as 2 inches of water
  • Bio-scrubber reduces the effort required maintenance


  • The flow rate is not adjustable
  • Occupies space inside the tank

How to Buy the Best Aquarium Filters

How to Buy the Best Aquarium Filter

1. Type of Aquarium Filter

Aquarium filters are available in 4 main types. These are:

Hang on Back Filter: These are the most common types of aquarium filters because they are very easy to maintain, yet they provide excellent mechanical, chemical and biological filtration.

The units are hung over the aquarium walls with tubes extending downwards into the tank for sucking water, after which it is passed over to the filter pads, activated carbon and biological filter cartridges. Modern HOB filters, however, feature bio-wheels, which are more effective at biological filtration.

Another benefit of this type is that they are usually small and lightweight, and this is primarily so as not to break the aquarium glass on which they are hung on.

However, they are better to use on small aquariums because their small size means that they have small filtration media.

Canister Filters: These are very good aquarium filters because they usually have large filter media volumes, which can house a lot of media for providing a large surface area to contact with the water.

Additionally, some of them feature UV sterilizers for an additional fourth stage of filtration, making them very powerful.

Due to their large size, they are the best types for large aquariums, say from 40 gallons and above.

However, they can be extremely big and heavy and also cost a lot more as compared to HOB filters.

Undergravel Filters: As the name suggests, this type of filter is usually placed under the gravel. They pull the water through this substrate by using air stones or a power head connected to their uplift tubes.

By doing this, under-gravel filters convert the substrate into a biological filter where beneficial bacteria grow. Gravel also acts as a mechanical filter but it's not very effective because of the large cavities that exist in between.

On the bright side, they are usually very affordable.

Internal Filters: Internal filters are usually compact and are placed inside the tank using suction cups to stick on the tank wall.

The advantage with this type of filter is that it can be used on shallow aquarium waters such as on tanks containing turtles, and creates a waterfall effect by releasing water from the top.

On the downside, these filters occupy space that is meant for the animals inside the tank.

There are other types of filters such as sponge/air driven filters, wet/dry or trickle filters and fluidized filters, but these are not very popular.

Buying Guide: In selecting the best type, HOB filters are usually the best if you have a small tank of up to about 50 gallons while canister filters are the best for the extremely big tanks.

Undergravel filters are not a very good option because they usually have only a 2-stage filtration system. Internal filters, on the other hand, are better off for tanks that are not filled to the brim, such as turtle tanks.

2. Tank Size

Before buying any aquarium filter, it is a must that you check its tank size rating. For instance, if you have a 100-gallon aquarium, you should buy a filter that is suitable for this size or more, such as a 100 – 150-gallon tank rated filter.

If you get a unit that is rated for a smaller volume of water, it won’t be able to maintain your tank’s cleanliness, especially if you have a lot of fish.

3. Filtration System

Filtration systems are rated in stages, with the best one being a 3-stage filtration system. This features a mechanical, chemical and biological filter, resulting in the production of clean water on the other end.

However, certain additions such as a UV sterilizer adds the fourth stage and this makes the system even better. UV kills algae and bacteria, resulting in very clear water.

4. Flow Rate

Given in GPH, the flow rate is important to consider because it determines how fast you filter will turn over the water in your aquarium. If you have a big aquarium, always ensure that you get a filter with a faster flow rate.

In fact, always make sure that the flow rate value is bigger than your tank’s capacity so that the filter can turn over your whole aquarium in less than 1 hour.

Another desirable feature to consider is an adjustable flow rate because this will give you more control over the filtration process.  


Aquarium filters are somewhat complex appliances that you should get to understand before buying one for your tank.

For this reason, this review article of the best aquarium filters in the market is very important to go through, especially if you are a newbie aquarist, and will certainly help you pick the most suitable unit for your tank.