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Most enthusiastic aquarium owners understand the importance of good filtration for a safe aquarium and will not compromise water quality for any reason. You’ve surely already tried a few different brands and types of aquarium filters and have owned a few decent filters over the years, but you’re always on the lookout for your perfect aquarium filter.

What type of filter is the best filter for my fish tanks?

Before diving into the options, it might be advantageous to do a quick review of some of the critical points in the filtration process and what a tank owner should look for in an aquarium filter.

A Quick Comparison of the 10 Best Aquarium Filters.


Product Features
Fluval FX6 Canister FilterFluval FX6 Canister Filter Style: Canister
Filtration Volume: up to 400 gallons
Dimensions: 15.75 x 15.75 x 20.8 inches
AquaClear HOB Power FilterAquaClear HOB Power Filter Style: HOB
Filtration Volume: 20 to 50 gallons
Dimensions: 4 x 9 x 8 inches
Marineland Penguin Power FilterMarineland Penguin Power Filter Style: HOB
Filtration Volume: 30 to 50 Gallons
Dimensions: 8.25 x 6 x 7.38 inches
Aqueon Large Filter Quietflow InternaAqueon Large Filter Quietflow Internal Style: Internal.
Filtration Volume: Up to 40 Gallons.
Dimensions: 6.5 x 5.69 x 11.19 inches.
Penn Plax Cascade HOB FilterPenn Plax Cascade HOB Filter Style: HOB.
Filtration Volume: 50 to 100 Gallons.
Dimensions: 9 x 6.5 x 11 inches.
Penn Plax Premium Undergravel FilterPenn Plax Premium Undergravel Filter Style: Undergravel
Filtration Volume: Fits 29 Gallon Tanks
Dimensions: 9 x 6.5 x 11 inches.
Dennerle Internal Corner Power FilterDennerle Internal Corner Power Filter Style: Internal Submersible
Filtration Volume: Up to 20 Gallons
Dimensions: 7.7 x 3.9 x 2.4 inches
Hydro 3 Sponge Filter

UPETTOOLS Sponge Filter

Style: Sponge
Filtration Volume: Up to 15 Gallons
Dimensions: Variable
Marina Internal Power FilterMarina Internal Power Filter Style: Internal
Filtration Volume: Up to 6.6 Gallons
Dimensions: 3 x 3.2 x 8 inches
EHEIM Classic External Canister Fish Tank FilterEHEIM Classic External Canister Fish Tank Filter Style: Canister
Filtration Volume: Up to 40 Gallons
Dimensions: 6 x 4.33 x 11.42 inches

Aquarium Filtration Systems

Filtration solutions have increased in the last few years as new types of filters have entered the market and older systems have been upgraded. It is easier than ever to find the right filtration device for any size fish tank, and most systems are very affordable!

Today’s filtration systems are an effective, simple, and inexpensive way to keep water free of biological waste and neutralize debris without having to do frequent water changes. First of all, we must talk about the characteristics of the filter card and what type of filters are ideal for the different aquarium configurations.

Mechanical Filtration

Mechanical filtration removes debris by passing the water through a fine mesh or wool, called mechanical filter media. Filter pads or sponge filters are the most common media used on filtration systems and almost all types have them as the primary stage.

Chemical Filtration

Many filters use activated carbon or different types of resin to absorb the toxic substances dissolved in your aquarium water. These media are usually in a bag, cartridge, or internal basket within your filtration system. This is the second most common feature you will see available in aquarium filters.

Biological Filtration

Biological filtration is one of the most important types of filtration in the aquarium hobby. This stage promotes the growth of “good” bacteria in the aquarium. These microorganisms feed on the dangerous ammonia and nitrites in the water, converting them into phosphates, a safer substance for our fish. If we provide them with the right environment for their proliferation, these bacteria will keep our water free of ammonia, nitrites, and nitrates. Many filters use these media as an intermediate stage, while others use them as the final stage of aquarium water filtration.

Types of Aquarium Filters

What type of aquarium filter is best? The size of your aquarium, the substrate, and the species it houses play an important role. In the last 20 years, filter types have become much more sophisticated.
Below are descriptions of the most popular types of filters for sale:

Sponge FiltersSubmersible FiltersUndergravel FiltersHOB FiltersCanister FiltersSumps Filters

Sponge Filters

Sponge filterSponge filters were once the most basic and were principally used in hospital and breeding tanks, as well as for rearing fry. They are a gentle filtration device that is powered by an air pump and suctions dirty water through a thin sponge-covered inlet. The primary purpose of these filters is to remove huge, visible debris from aquarium water.
Modern sponge filters can also have a biological stage that can not be beneficial to diseased fish but can only be used in a long-term aquarium. Their ability to filter out debris is limited, and they must be cleaned weekly to avoid clogging. A month of use is required to cycle the water and establish healthy bacteria.

You should keep sponge filters on hand in case of an emergency, but they are insufficient for my planted tanks or large community installations. I do not rely on them as a primary form of filtration because they cannot chemically neutralize the ammonia. But for small Betta or freshwater aquariums, they are a great choice.

Submersible Filters


Submersible filters, which are mounted inside your aquarium, are one of the newest varieties. Easy 1- or 2-stage filters are ideal for fish tanks and nano aquariums, whereas more complex 3-stage filters can be concealed in the tank’s bottom corner. They can be electric or run on compressed air.

They can provide a lot of filtration power to the right setup, depending on their size and number of stages. They’re perfect for smaller fish tanks without enough space for a HOB or external canister filter, as well as larger goldfish and shrimp aquariums with little current.

As long as there aren’t too many fish or bottom feeders in the tank, some 3-stage electric models have enough flow to fit well in planted aquariums. Air pump-powered models are typically unsuitable for planted or larger group fish aquariums, but they perform well in smaller setups.

Undergravel Filters

Under-gravel Filter

Gravel filters perform limited two-stage filtration by drawing dirty water through the substrate before passing through the filter pad/media. Larger particles and debris are stuck in the substrate and are either broken down by bacteria or vacuumed out by your bottom feeders or during water changes.

A gravel filter is made up of three parts: a plastic mesh that sits underneath the gravel layer, an outlet tube with a replaceable cartridge containing the filter pad and filter media, and an air pump that feeds the filter through a plastic tube. In most cases, the pump and plastic tubing must be purchased separately from the filter.

Many of us got our start with under gravel filters, which were once thought to be the perfect model for beginning aquarists. Internal and submersible filters, on the other hand, offer greater filtration for a comparable price and are much easier to maintain. Undergravel filters, in my opinion, should not be preferred over the other alternatives.

HOB Filters

HOB Filter

HOB (hang on back) filters are one of the most common types of filters on the market, and they’re ideal for both freshwater and saltwater fish tanks. They have an inlet tube that carries water to the filter for cleaning and are hung externally on the side or back of the tank. These forms are simple to maintain since they do not require reaching into the tank.

The electric pump (impeller) and filtration stages are housed in the main unit. The water travels up the inlet tube and through the stages before returning to the tank through the outlet vent. HOBs have 2 to 3 filtration stages and a versatile setup that can be adjusted to suit most aquariums.

Sponge, submersible, and gravel filters are easier to mount and maintain than HOBs. The less costly versions are very similar to the basic internal type and have similar filtration. Three-stage HOBs of superior quality can be as powerful as cartridge filters, and they’re often used in tandem for large or planted aquariums.

Canister Filters

Canister Filter

Professionals and seasoned aquarists with wide aquariums ranging from 50 to 500 gallons used to prefer canister filters. These strong electric filters are normally concealed by the support and mounted beneath the aquarium. Water is drawn from the intake and pumped through the filter pad and stages in the cartridge.

A canister filter’s ability to transfer a lot of water through the stages is one of its benefits, making it suitable for very large tanks. Since the container is closed, less water evaporates and the noise level is reduced compared to HOBs. The outlets can be adjusted to reduce flow and splashing.

Several filter pads are normally used in the canisters to polish the water and remove microscopic particles. Other stages can normally be tailored to provide your aquarium with the exact combination of neutralizing chemicals and biological media it needs. They are, however, more difficult to run and maintain, and they typically cost more than other styles.

Sumps Filters

Sump Filter

I’ll go over sump filters briefly because these complex systems are rarely seen in freshwater aquariums outside of the professional aquascaping world. They can, however, be an important part of keeping a saltwater or reef tank healthy.

A sump system is a method of providing biological filtration to a broad aquatic system in a slow, incremental manner. A sump is normally placed immediately below or to the side of a saltwater aquarium, and water enters the sump through gravity through holes or overflow from a siphon. The water is oxygenated and bacterially flushed as it goes through the steps.

The installation of a sumps filter is difficult, takes up as much space as the aquarium, and provides predominantly passive organic filters, although some systems have filter media slots. They are also quite pricey. They are not suitable for freshwater aquariums, in my opinion. I would use a HOB or canister for external fish tank filters.

How to choose the proper Aquarium Filter

Tank Size and Occupants.
Fluval FX6 Canister Filter

You will most probably choose sponge, low flow, internal, or submersible systems for smaller aquariums of 10 gallons or less. Betta, shrimp, and plant health are better than a sponge or in gravel systems, because of the immersible and internal types.

When more filtration, like for goldfish and plants, is needed, HOBs are a good choice. They are available in the widest range of sizes and are suited for 5 to 500-gallon tanks. I recommend that you read aquarium filter reviews before selecting the model for many brands and pricing.

For tanks under 20 gallons, canister filters are usually too strong. You can never have too much current or circulation for your fish’s comfort, particularly if you have Bettas or goldfish. A cartridge filter, on the other hand, can be a great cost-effective choice for planted tanks and large community aquariums over 50 gallons.

Filter Flow Rate
Aquarium Filters Flow Rate
Flow rate, or the number of gallons that pass through the filter per hour, is how most motorized filtration systems are classified (gallons per hour or GPH). These are estimates, and the flow rate of your tank will be affected by how you set up and maintain your filter. The flow rate will be significantly reduced if your filter pads get clogged with debris.

The optimal flow rate for an aquarium is a point of contention. According to some websites, you can get a filter with a GPH of up to 6 times the size of your tank. For the most part, I’ve noticed that this is too much for most of my tanks. A 120 GPH filter isn’t normally needed for a 20-gallon installation.

Filtration Technology
Aquarium Filters
Choosing the best fish tank filtration device does not always imply selecting the most recent or technologically advanced model. After all, even though they are difficult to set up and manage, sumps work on a very old and basic concept. The more sophisticated your filtration device, the more likely something could go wrong.

Instead, search for tried-and-true systems that have already proved themselves in a variety of tanks around the world. A good simple filter will sometimes perform as well as, if not better than, a filter with a lot of technical features. Instead, choose filters with easy-to-maintain features like silicone gaskets and easily accessible pads and media.

In the aquatics industry, I am a brand loyalist. The explanation for this is that I am wary of new aquatic businesses. For many reasons, I dislike filters made by unknown brands. To begin, choose a brand for which replacement parts and filter pads/media are readily available both locally and online.

In the long run, well-known goods and brands with an established track record are typically more cost-effective. Impellers, for example, appear to last longer, so you don’t have to replace them as often. Online forums will also provide you with advice about how to change your filter. A leaking cheap filter will cause a lot of damage to your floors.

Reviews of Top 10 Best Aquarium Filters

Let’s take a look at some of the best aquarium filters available. These filters were chosen because they are made by well-known brands, use cutting-edge filter technology, and have easy-to-find replacement parts. I can confidently state that I would purchase these filters on my own, and in some cases have already done so.

1. Fluval FX6 Canister Filter

Fluval FX6 Canister FilterStyle: Canister
Capacity: Up to 400 Gallons
Dimensions: 15.75 x 15.75 x 20.8 inches
Flow Output: 925 GPH

Check Price

The Fluval FX6 is an excellent choice if you need a professional aquarium filter for a wide aquarium of up to 400 gallons. It has so many features that I can’t even begin to list them all. The FX6 is a high-performance, self-priming filter that is virtually leak-proof. With an accessory kit, you can even use it to perform water changes!

The stackable media baskets are one of the most impressive features. You can personalize your filter media, and the seals prevent water from passing through the baskets. The auto-stop valves also keep water from leaking or re-entering your tank.

Fluval FX6 Canister Filter Pros & Cons
  • The filter has a high capacity and a high-performance rating, and it is of professional-grade quality.
  • It has many unique features, such as a self-priming pump and a variable speed motor, which help to maximize performance.
  • You can use the filter motor to pump water out of your tank during water changes with an additional kit.
  • The filter is also the most expensive on the list.
  • It is too powerful for aquariums under 200 gallons and does not come in smaller sizes.
  • Such large aquariums will almost certainly necessitate the use of secondary filtration systems.

2. AquaClear HOB Power Filter

AquaClear HOB Power Filter

Style: HOB
Capacity: 20 to 50 Gallons
Dimensions: 4 x 9 x 8 inches
Flow Output: 200 GPH

Check Price

The AquaClear power filter might be the best choice for your home if you’re looking for a HOB filter for a bedroom aquarium or one in a location where sound could be an issue. It’s the quietest filter on my list, and one of the quietest HOB filters I’ve ever used. It would also work well in conjunction with a canister system!

This filter isn’t particularly fancy, which is to its advantage. It is quiet because it lacks a “bio-wheel” and does not splash as much water as some HOBs. The flow rate is adjustable, making it ideal for sensitive fish and shrimp aquariums. It’s a surprisingly long-lasting filter with a great two-year warranty.

AquaClear HOB Power Filter Pros & Cons
  • This filter is the quietest on the list, thanks to its extremely quiet motor and minimal water splashing.
  • It has three stages of filtration and comes with filter media.
  • Since the flow rate can be adjusted, it can be used in shrimp, Betta, and goldfish tanks.
  • Water will bypass the biological stage at higher flow rates because of the filter box’s design.
  • To protect delicate organisms from damage, you may need to cover the intake with a sponge tip, which will reduce the flow rate.
  • Larger tanks can require additional filtration systems.

3. Marineland Penguin Power Filter

Marineland Penguin Power Filter

Style: HOB
Capacity: Up to 30 Gallons
Dimensions: 8.25 x 6 x 7.38 inches
Flow Output: 150 GPH

Check Price

I’ve owned at least five Marineland power filters in various sizes, and I believe these are among the best premium HOBs available. They have dependable 3-stage filtration with an adjustable flow rate, and I’ve only had a few instances of water bypassing the media.

The patented “Bio-Wheels” for sustaining colonies of healthy bacteria are a standout feature of this filter. There’s probably no other HOB that can do bio-filtration as well as this one. However, those wheels significantly increase the noise and mess created by the splashing water. You’ll spend a lot of time removing deposits from your tank if you have hard water.

Marineland Penguin Power Filter Pros & Cons
  • Provides three-stage filtration with “Bio-Wheels” for the growth of beneficial aquatic bacteria colonies.
  • Water cannot pass through without passing through each stage due to the high-quality nature.
  • Replacement parts are readily available both online and in local pet shops.
  • ”Bio-Wheels” increase noise and evaporation, making them an unappealing choice for bedroom tanks.
  • To start water circulation, the filter must be primed, and it may not restart on its own after a power outage.
  • On rimless or custom-shaped tanks, this filter is difficult to mount.

4. Aqueon Large Filter Quietflow Internal

Aqueon Large Filter Quietflow InternaStyle: Internal
Capacity: Up to 40 Gallons
Dimensions: 6.5 x 5.69 x 11.19
Flow Output: 290 GPH

Check Price

This internal Quietflow model from Aqueon is one of the best 40-gallon aquarium filters. It hangs or is suction-cupped to the inside of your tank, similar to a HOB, except instead of hanging outside, it hangs inside. This is a fantastic choice for a planted aquarium with a small number of fish.

However, I wouldn’t use this filter with delicate species because the flow rate can’t be adjusted to match the gentle currents they prefer. In certain tanks, reaching into the filter to adjust the media may be difficult. It’s still the choice I’d choose for a plant-focused tank up to 40 gallons, and it’s still very affordable.

Aqueon Large Filter Quietflow Internal Pros & Cons
  • With a hanger or suction cups, it’s easy to lock in the upper part of your tank.
  • It has three filtration stages and even a biological stage.
  • It has a high flow rate of up to 290 GPH, making it ideal for planted tanks.
  • Changing the filter pad and media can be difficult depending on the design of your hood or lid.
  • It’s nearly a foot long, so it’ll stand out unless it’s concealed behind your tank’s decor.
  • The motor is very noisy, making it unsuitable for a bedroom aquarium.

5. Penn Plax Cascade HOB Filter

Penn Plax Cascade HOB FilterStyle: HOB
Capacity: 50 to 100 Gallons
Dimensions: 9 x 6.5 x 11 inches
Flow Output: 300 GPH

Check Price

Find this Penn Plax HOB-style unit for the best 100-gallon aquarium filter. When you consider its low price, it’s a surprising workhorse of a filter. The Penn Plax, like many HOBs, has three stages of filtration, but unlike others, it also has a separate compartment that biologically cleans the water over time.

This filter has a high flow rate of 300 GPH and is easily adjustable, so you can lower it at mealtime to avoid food being sucked into the intake. It also has a relatively quiet engine, but not quite as quiet as the AquaClear. This is a fantastic choice for a big aquarium!

Penn Plax Cascade HOB Filter Pros & Cons
  • Filtration in three stages, each with its own compartment for the biological level.
  • For delicate organisms, a high-capacity, adjustable flow rate of up to 300 GPH is ideal.
  • Suitable for planted and fish-only tanks.
  • The motor isn’t as quiet as some other models, and water splashing is audible.
  • Filter pads and replacement parts with a brand name may not be as readily available in your local pet shop.
  • For large or heavily planted tanks, you can also need another filtration device.

6. Penn Plax Premium Undergravel Filter

Penn Plax Premium Undergravel FilterStyle: Undergravel
Capacity: Fits 20-Gallon Long or 29-Gallon Tanks
Dimensions: 28.5 x 11.5 x 1.2 inches
Flow Output: Variable- Depends on Air Pump

Check Price

These days, I don’t recommend undergravel filters very much because there are so many other solutions that work just as well or better. However, for planted tanks, an undergravel is often the most cost-effective and convenient alternative. This Penn Plax model is a standard undergravel system for a new aquarium. Simply add a power source, such as an air compressor.

Although undergravel systems leave debris in your substrate, this is less of an issue in planted tanks with less fish. The Penn Plax will provide enough filtration and circulation to keep your plants satisfied as long as your bio-load isn’t too high. You won’t have to worry about dead zones in your substrate!

Penn Plax Premium Undergravel Filter Pros & Cons
  • Filtration for 20 or 29-gallon tanks is given in two stages.
  • Filtration runs the length of the tank’s floor, avoiding dead zones in the substrate and around the plants.
  • An undergravel system needs very little maintenance once it is built.
  • For most fish-only setups, it is insufficiently filtered.
  • To biologically filter your water, you’ll have to depend on your substrate and its population of good bacteria.
  • An air pump is still needed for power in a low-cost filtration system.

7. Dennerle Internal Corner Power Filter

Dennerle Internal Corner Power FilterStyle: Internal Submersible
Capacity: Up to 20 Gallons
Dimensions: 7.7 x 3.9 x 2.4 inches
Flow Output: 40 GPH

Check Price

I wish this sort of filter had been available when I was a kid because I would have loved to have had this Dennerle internal corner power filter! It’s an internal submersible filter with an adjustable spray bar for the outflow that hides in the corner of your tank.

The Dennerle is extremely quiet, and its 40 GPH capacity is ideal for Bettas and shrimp. However, the 3-stage filtration is appropriate for goldfish and planted aquariums. Although you will have to reach into your tank to adjust the pad and media, it is a simple process that does not require you to remove the entire tank!

Dennerle Internal Corner Power Filter Pros & Cons
  • The submersible filter is tucked away in the corner of your aquarium.
  • Is delicate enough for Bettas and shrimp, and with an aftermarket projector, it can also be used to raise fry.
  • For tanks with a capacity of 20 gallons or less, this is an excellent premium filter choice.
  • It costs more than many internal filters and about the same as a standard HOB filter.
  • You have to reach into the tank to adjust the media and access the filter pad.
  • Replacement parts are difficult to come by and will have to be shipped in from Europe.

8. UPETTOOLS Sponge Filter

Hydro 3 Sponge FilterStyle: Sponge
Capacity: Up to 15 Gallons
Dimensions: Variable
Flow Output: Depends on an air pump

Check Price

Sponge filters are usually single-stage devices, but this upetstools alternative adds biological filtration to the mechanical filtration for longer-term use. It’s an excellent choice for raising fish and shrimp fry, and while hospital tanks don’t need bio-filtration, you can still use the Hydro for them.

This is box title
  • Adjustable nature is suitable for raising fish fry and shrimp and provides mechanical and biological filtration with a low, gentle rate of circulation.
  • Maintenance is minimal, and new parts are rarely needed.
  • Only 1 to 2 levels of filtration are available, and if used for a limited period of time, only a single stage is available.
  • If algae grow inside the tubing, it’s difficult to clean.
  • It’s not a particularly long-lasting design, and replacement parts can be difficult to come by.

9. Marina Internal Power Filter

Marina Internal Power FilterStyle: Internal
Capacity: Up to 6.6 Gallons
Dimensions: 3 x 3.2 x 8 inches
Flow Output: 24.6 GPH

Check Price

A nano tank is one of the best applications for an internal filter, and Marina’s system is a classic! The Marina, like the Aqueon, hangs inside your tank and is accessed from the top. It gently returns your water to your tank after filtering it through a multi-stage one-piece replaceable cartridge.

For tanks up to 6 gallons, this is a great choice. Since it is substituted along with the other levels, I doubt the degree of biological filtration is very high. However, this tough little filter does the job and is nearly as simple to use as a sponge filter.

Marina Internal Power Filter Pros & Cons
  • Filters small nano tanks under 6 gallons in three stages.
  • Single-piece snap-in cartridges are simple to adjust with one hand.
  • For this filter, you’ll never have to cut padding or fiddle with media bags.
  • Given how often the media is replaced, it’s unlikely that it offers any biological filtration.
  • The flow rate isn’t adjustable, and it’s difficult to change with a baffle without compromising filtration.
  • You’ll need to be able to accommodate this in the top section of your tank because it’s not completely submersible.

10. EHEIM Classic Canister Aquarium Filter

EHEIM Classic External Canister Fish Tank FilterStyle: Canister
Capacity: Up to 20 Gallons
Dimensions: 6 x 4.3 x 11.4 inches
Flow Output: 40 GPH

Check Price

I wouldn’t normally suggest a canister device for a small 20-gallon tank, but laws are made to be broken. For a small tank, a high degree of filtration is often needed. If you have goldfish or a Betta sorority, you’ll probably enjoy this canister filter from the reputable Eheim company.

The built-in canister stand, which keeps the filter from tipping over, is my favorite feature. I’ve had canister filters leak when they’ve been tipped, so this is a big plus. The silicone seals have a water-tight seal that is both durable and easy to repair when they wear out. This is a very adaptable and scalable device.

EHEIM Classic Canister Aquarium Filter Pros & Cons
  • The 3-stage canister filter can be customized to use the filter pads and media of your choice.
  • Silicon seals are long-lasting and avoid leakage and motor noise.
  • When stored next to or under your tank, the built-in foundation stops the filter from tipping over.
  • It’s more difficult to find replacement and accessory parts for older model filters.
  • It’s an expensive filtration device that might be out of reach for some hobbyists.
  • Although the spray bars and intake can be modified indirectly to slow the flow, the flow rate is not adjustable.

Final Thoughts

Finding the best fish tank filter you can afford is the key to keeping your aquarium sparkling clean without putting in a lot of extra work. The best choice will be determined by the size and setup of your tank, and many people choose to use more than one form of filter. As your tank and fish grow, you can always add another filter.

Marina, Hydro, Penn Plax, and Dennerle are all viable choices for nano tanks and small aquariums under 20 gallons.

  • It’s simply a matter of preference between an internal, sponge, undergravel, or submersible device.
  • If the Dennerle worked for my tank, I’d probably go for it.

Eheim, Penn Plax, AquaClear, and Marineland are all good choices for the mid-size range of 20 to 75 gallons, depending on the features you need and the fish and plants you plan to keep. If you have very rough tap water, stay away from the Marineland or you’ll have a lot of build-ups to clean out of your tank.

Larger tanks over 75 gallons should use the AquaClear, while tanks between 250 and 400 gallons should use the outstanding, premium Fluval FX6. Just to justify having the Fluval, I’m tempted to start a 400-gallon aquarium.

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