10 Best Aquarium Filters

This post is a review of the 10 best aquarium filters.

The water filtration system is arguably the single most important piece of equipment a fishkeeper needs to keep their fish happy, healthy, and thriving.

Without a filtration system in place in an aquarium, the water will quickly become polluted with toxins and debris, potentially leading to cloudy water, the lack of beneficial bacteria, and ill or dead fish.

Selecting the best fish tank filter depends on the needs of the aquarist.

There are plenty of great water filtration systems available on the market to solve the problem of needing an aquarium filter; however, knowing the best one to pick for your tank may not be as easy.

Not every water filtration system is created the same.

There are different brands of aquarium water filters, different types of filters such as an external canister filter and power filter, different kinds of filter media, and different models and filtration cartridges for different kinds of aquariums.

In this post, we will take a look at 10 of the best aquarium filters and discuss how they stack up against each other based on their features and benefits, as well as cover how to choose the best aquarium filter for your fish species and overall aquarium setup.

The fish aquarium filtration system is a very important part of the aquarium.

Not only do you need to maintain a healthy fish environment, but it is also an all-important component for the general maintenance of your aquarium.

Fish tanks are not difficult to maintain, but they do require time and effort.

A thorough understanding of what is required for proper maintenance will provide fish owners with peace of mind that their pet has a safe home while also keeping them healthy and happy.

Aquarium filters are designed in many different ways to best suit your needs – from choosing between under the gravel or external filter options to deciding which filter is best for your fish species, and even what size is best for your aquarium.

Modern filtration systems are an efficient and easy way to keep your water free from debris and neutralize biowaste without having to do weekly water changes. Before I can pass on my tips for choosing the best freshwater aquarium filters, we need to talk about their features and which types are ideal for different aquarium set-ups.

The water in a fish aquarium is constantly flowing, passing over the solids that have settled on the bottom of the tank, such as uneaten food, settled debris, and fish waste.

The filtration system is designed to keep your fish tank free from this type of material so your water remains clean and healthy for your fish.

The particulates are removed that would be harmful to fish health if allowed to linger in the water for an extended amount of time.

Before jumping into the best aquarium filters or even the types of filters, it is important to understand how aquarium filters work. This will help you select the best filter for your aquarium setup and fish species.

The filtration cleaning process is one of the most important things to understand as a fishkeeper.

Without the knowledge to keep your tank clean, the water quality may get low enough to affect the health of your fish.

The task seems like a simple one, and while it isn’t difficult, preparation and the right equipment are a necessity. Otherwise, an expensive mistake can easily happen.

Tank filters clean the water by collecting debris and other impurities that are in the water using filter media.

Filter media is anything placed in the tank filter that alters the quality of the water flowing through it.

There is a variety of filter media on the market. The specific type you select should be based on your aquarium inhabitants and environment.

When you purchase a new aquarium, you’ll need to choose one or more filters for your fish, selecting from mechanical, biological, and chemical.

Biological filtration provides healthy bacteria for your fish to thrive on by removing ammonia from their environment.

Mechanical filters collect larger pieces of waste while a filter’s chemical media removes organic compounds from the tank water.

Chemical Filtration cleans the water by removing organic compounds from the tank water.

After these phases have been completed, clean water will be released back into your aquarium as it was received without any trash or harmful chemicals inside.

The best kinds of filters will remove ammonium without releasing harmful chemicals back into the environment and are easy to maintain with regular cleaning cycles that take less than 15 minutes each week.

These include the canister filter, hang-on-back or HOB filter, under gravel filter (UGF), box-type models, a wet/dry trickle filter, foam blocks, and sponge air pumps.

Each will be covered in detail a few paragraphs down the page. First, we will discuss the types of aquarium filtration media.

There are three types of filtration media, including biological and mechanical filtration as the first two, and chemical filtration as the third type.

Biological Filtration

The biological filter process is a key component of most aquarium filters.

It is the process by which beneficial bacteria break down ammonia and nitrite, converting them into harmless compound nitrate.

The bacteria in your filter helps break down ammonia into nitrates and then convert them to nitrogen gas which is released out of the tank when it’s filtered through this stage.

Beneficial bacteria thrive in oxygen-rich water with surfaces they can attach to, such as sand or rocks.

All fish tanks should have some means to perform biological filtration since this method alone might be enough to sustain an aquarium that houses small fish populations.

However, many larger tanks will employ additional methods due to their size requirements. Examples would be mechanical filters and chemical treatments along with biological filtering.

Bio-Wheel Power Filter

A bio-wheel is an apparatus used in the biological filtration process. This biological filter incorporates a porous mesh rotating paddle-wheel to filter the water.

The wheel enters and exits the water as it turns, ensuring the mesh is exposed to water and air basically at the same time.

During the process, beneficial bacteria are developed since they require air to grow.

Bio-Ball

A bio-ball is used in the biological filtration process to remove harmful ammonia buildup produced from fish waste from your water.

Bio Balls are small spherical plastic shapes with grooves and ridges in them. They have openings that provide a place for nitrifying bacteria to grow, which is necessary for fish to survive.

Essentially, the purpose of each bio-ball is to house and grow populations of beneficial bacteria.

Mechanical Filtration

Mechanical filtration is the most common type of debris removal in a home aquarium system.

Mechanical filtration removes solid particles from water by circulating and straining them through some kind of tank filter.

This process alone may not be sufficient since mechanical filters do not remove or convert ammonia, nitrate, or nitrite that are found in tap water.

It’s important to understand that you need both kinds: first removing free-floating waste before they decay into harmful substances and then cleaning or replacing the filter medium every two weeks so as not to harm your aquatic pets with potentially toxic levels.

Mechanical filtration does not only focus on removing the contaminants from the water, it also aids in the process of aerating the water for increased fish health.

Chemical Filtration

Chemical filtration uses activated carbon to remove chemical additives from the water.

Activated carbon is a form of charcoal that has been processed and made porous.

When you put activated carbon in the filter system, it will absorb all impurities like chlorine or ammonia from tap water for up to six months before needing to be replaced.

Chemical filters are designed to remove organic pollutants from the water that are not removed by biological and mechanical filtration.

There are numerous types of aquarium filters on the market, each with its own benefits, style, and design.

Power Filter

Hang on Back filters are typically referred to as HOB filters. They are also referenced as a power filter.

The HOB filter is the most commonly used type of aquarium filter.

It removes water from the fish aquarium with a siphon and pushes/pulls it through filter media then returns it to the tank.

Power filters are an effective means of water filtration, and in most cases, they are simpler to maintain than an internal aquarium filter.

 There are advantages to using a power filter, including:

•  There is a large selection of filter media based on aquarium needs.
•  Easy to clean without disturbing the fish because they are located on the exterior of the tank.

 The disadvantages of using a power filter:

•  They have a smaller capacity for filter media in comparison to canister filters.
•  They can be noisy as a result of filter vibrations against the tank.

Canister Filter

Canister filters were originally introduced for the filtering of drinking water using low pressure.

With the development of the aquarium external canister filter came the need for high water pressure so there was enough power to force water to get through the density of the filter material.

With a canister filter water enters via the intake pipe located at the bottom of the canister, it passes through the filter material and then feeds back into the aquarium through the return pipe.

It houses a pump, typically located at the top of the canister, that forces water to circulate through the filter.

The canister filter system is a sealed and complete flood system. The aquarium, intake pipe, filter interior, and return pipe are enclosed and act as one unit of water.

Two siphons are included in this configuration, including the intake and return path, which counterbalances one another.

This is effective because the filter pump can easily lift the water and return it to the aquarium no matter how high the intake siphon is located in the canister.

Advantages of a canister filter:

•  In comparison to HOB filters, canister filters offer more flexibility for filter media (material).
•  The interior space of the aquarium is not compromised.
•  The filter material can offer high volume since the size is not an issue with it being outside the tank.
•  Easily disconnected from the tank for cleaning and maintenance without disturbing the fish.
•  Since the plumbing is outside the aquarium, other aquarium equipment is easier to install such as carbon dioxide diffusers and water heaters.

 The disadvantages of a canister filter:

•  Canister filters can be more difficult to clean because of the two siphons, with a greater risk of damage from incorrect cleaning.
•  Typically cost more than an internal filter setup.
•  Higher risk of a water leak because as an external filter they are located on the exterior of the tank.

 Diatom Filter

A diatom filter is not a commonly used or well-known type of aquarium filter.

They are not a continuous process filter, meaning they are used for periodic tank cleaning and maintenance to manually remove the debris and waste from the bottom of the aquarium.

Trickle Filter (also known as a Wet Dry Filter)

Trickle filters are used in freshwater aquariums and saltwater tanks.

These filters are available in two layouts. The first layout places the filter on top of the aquarium, and the second option places the filter below the aquarium.

In the layout that houses the filter on top of the aquarium, water pumps over the top of perforated trays filled with the filter media, typically wool.

As the water trickles through the perforated trays, it ensures the filter wool (or other material) stays damp and not completely submerged in water.

This allows beneficial bacteria to grow so biological filtration can occur.

In the second layout option, the trickle filter is placed below the tank. Gravity pulls the water to the filter since it is below the aquarium, then prefiltered water is passed to a perforated drip tray.

The prefiltering can occur inside the tank through a siphon, a sleeve in the overflow, or via filter media laying on the perforated plate.

The water with the debris and waste gather on the perforated drip tray where it strains through to the filter material for cleaning.

The cascading water releases carbon dioxide, then picks up oxygen, and bacteria convert the debris and waste into less harmful material.

At this point, the water enters a compartment of the sump which is filled with filtration material to clean the water.

 Algae Filter

Algae are known to have properties that remove harmful chemicals in the water, creating a healthy environment for fish.

Algae filters offer a similar filtering process that replicates the natural cleaning process in lakes and oceans.

Baffle Filter

Baffle filters are located below the aquarium, similar to a trickle filter.

They are made up of multiple baffles the water passes through on its way to the pump, which returns the water to the aquarium.

The baffles act in a similar way as a canister filter with each filled with different filter materials depending on the desired outcome.

 Internal Filter (also called Submersible Filter)

Internal filters are another type of fish tank filter. They are located inside the aquarium.

An internal or submersible filter is an aquarium filter that is placed in the tank and submerged underwater.

Many have an electric pump, making it an internal power filter.

They typically attach to the glass with suction cups.

This type of filtration requires no additional parts or equipment outside of the tanks themselves; however, they need to be cleaned regularly because an accumulation can occur underwater from waste build-up.

Internal filters can also be difficult to clean without removing the entire unit from its submerged state, which disturbs fish and other aquatic life swimming nearby.

Examples of internal filters:

•  sponge filter
•  corner filter variations
•  under gravel filter
•  foam cartridge filter

Airlift Filter

An airlift fish tank filter rises in a tube by using bubbles from the air pump to create water flow.

An airlift filter is an efficient filter, but it does not last as long as most other fish tank filters.

Airlift filters are also more expensive than some other types of aquarium filters, making the bottom line expense much more since they are also replaced more frequently.

However, they do provide a highly sufficient flow rate that can keep the water in the tank much cleaner for longer periods of time.

Examples of internal filters:

• sponge filters
• corner filters (also called box filters)

An open-cell block of foam covers the inlet with a sponge filter. They prevent small fish from being pulled into the filter, making them especially useful for in a breeding tank or for raising fry.

Corner Filters are more complex. They are generally placed in the bottom of the aquarium in the corner. The box has small openings, allowing the water to enter, pass through a layer of media, then exit via the airlift tube and return to the tank.

This type of filter is not suitable for large tanks or tanks that are heavily stocked.

Undergravel Filter

A premium undergravel filter is great for larger tanks that need a lot of filtration. This filter is installed under the gravel, so it will not disturb any living organisms on top of it.

The media in this type of filter needs to be replaced regularly or bacteria can build up and cause toxic ammonia levels in the water.

Undergravel filters have been on the market longer than most other filters. They are made of a porous plate that lays on the bottom surface of the aquarium beneath the gravel.

Undergravel filters have historically been driven using air displacement.

Air stones lay near the uplift intake tube base. The tubes force water out of the uplift tube causing negative pressure underneath the filter (also known as the plenum.)

Water then percolates downward and flows through the gravel, creating beneficial bacteria and utilizing biological filtration. The gravel or whatever substrate is used in the aquarium is the actual filtration media. (LINK)

If a higher water flow rate through the gravel is needed, this is achieved with the water pump, not the air displacement.

The water flow rate in the tank is important, as it is the power that drives water movement and filtration.

For example, if there are too many filters in a smaller tank with a low water flow rate, then the filter will be overworked trying to keep up with removing waste from all of the surfaces.

This can lead to an increase in nitrate levels because bacteria cannot break down these high concentrations quickly enough before they become nitrates-a which is a toxic byproduct of fish waste.

Once you know the fish species and any other aquatic life that will dwell in your tank, you are ready to pick out the filter based on their health and survival requirements.

Aquarium Filter Size vs Aquarium Size

In order to keep your aquarium cleaner longer, you need a fish tank filter that provides the correct water flow rate for your aquarium size.

The longer your aquarium stays clean, the healthier the environment will be for your fish.

Purchasing the right fish tank filter for your aquarium size is one of the main considerations.

Generally, the recommendation is that all the water in your tank should pass through the filter at least four times each hour. (source)

For example, if you have a 30-gallon tank, the water pump and filter flow rate requirement would be approximately 120 gph (gallons per hour.)

If it is a close call, move to the next higher flow rate.

 Aquarium Use and Flow Rate

The filter media you choose has a significant impact on controlling the water flow rate.

Biological and chemical media often work better at a rate of 4 times an hour or less.

But if the flow is less than one time per hour, perhaps due to filter material being clogged, it could deprive biological media of life-giving oxygen, possibly causing a sudden release of toxins.

Mechanical media, on the other hand, performs optimally with a higher flow rate, so a good balance between the two needs to be achieved depending on the media type and amount contained in the filter. (source)

 Aquarium Use and Flow Rate

• Aquariums with large fish should have a higher water flow rate filter, in addition to possibly adding powerheads that clean a large amount of fish waste out of the tank.
• Reef tanks also need a higher water flow rate filter so the water is continuously moving at all times.

Slow Flow

These aquatic inhabitants experience stress if they have to continually swim in a current.

• Live plant tanks
• Baby fish, betta tanks, and small fish

1. AquaClear Hagen Power Filter

2. Fluval FX High Performance Canister Filter

3. MarineLand Penguin 350 Power Filter

4. Penn-Plax Cascade Canister Aquarium Filter

5. Eheim Filter 2213-37 Classic

6. Marineland Magniflow Canister Filter

7. Polar Aurora 4-Stage External Canister Filter

8. SeaChem Tidal 75 Gallon

9. Polar Aurora 265GPH External

10. Aqueon Quietflow Power Filter

 1. Is it alright to have two filters in one tank?

It is not a problem to have more than one filter in your fish tank. In fact, this has a name and it is called redundant filtration.

In some instances, having multiple filters is recommended and better for your fish than just having one filter.

2. How often should you clean your filter?

Generally speaking, your aquarium filter should be cleaned approximately once a month.

Of course, this also depends on the type of filter, how many fish are in your tank, and the size of your tank.

3. Which filter is good for small aquariums?

The Marineland Magniflow Canister Filter is an excellent choice for small aquariums. It comes in three sizes, the smallest is for tanks up to 30 gallons.

4. Which is better internal or external aquarium filter?

The type of fish tank filter you select is probably different from your neighbors, and their neighbors.

Internal aquarium filters are less expensive than external filters, and they are better for small or medium-sized tanks that have small to medium-sized fish.

External filters don’t take up space inside your tank; however, they need additional space outside the tank.

The most important consideration when choosing your filter is to get one that has the best flow for your fish species and aquatic plants.

Keeping your aquarium water clean has to be a priority for fishkeepers if they want happy, healthy, and thriving fish.

With all the filters on the market, selecting one of the best aquarium filters for your tank simply takes time for research, budgeting, and then making the final selection.