Best Canister Filters for your Aquarium

I think, by this time, the importance of a filtration unit should be of no question to us. A good filter is a must in any aquarium as it helps keep your water clean from unwanted substances like floating particles, uneaten leftover food, ammonia, nitrate, and nitrite as well as provide the home for the beneficial bacteria that carry out the nitrogen cycle inside the aquarium.

But the topic that we discuss here today is specifically about canister filters. In this article we will discuss how a canister filter is different, what does it bring to the table that other filters do not? We review some of the best canister filters available in the market in detail, weigh in the pros and cons, give our verdicts and also help you understand what product may suit your needs if you do decide to get a canister filter for your tank.

So without further ado, let’s dive in.

What is a Canister Filter?

From the name, we can understand that the peculiar thing about a canister filter is the presence of a canister which basically means a plastic box. Canister filters, thus, are aquarium filters that remove the water from the fish tank through an intake tube, sieve or valve, run it through the filtration media that is enclosed in a pressurized canister, and then return the filtered water into the aquarium through a spillway or spray bar.

Why Should I Choose A Canister Filter?

The whole idea of a canister filter is to provide you with the advantage of selecting the type of filtration that is appropriate for your tank by customising the filter media rather than being stuck with the manufacturers’ pre made media cartridges. How the canister filter is different from other filters is that it makes the water from the aquarium pass through the filtration media rather than allow the water to flow over or flow around the media and ultimately returns the water to the tank through a spray bar which reduces evaporation and water current.


  • High water flow rate

Many canister filters allow you a superior water flow rate than other kinds of filters which makes them greatly suitable for water that needs a lot of filtration flow like the ones that have fish like African Cichlid.

  • Allows you a wide range of filter media

Other filters have prefixed filtration cartridges, they have a fixed filtration media that is chosen by the manufacturer. Once these cartridges run out of the filtration media you have to replace them with similar cartridges that can be bought separately. This needs you to be confined to only a few choices of filtration media. The canister filter overcomes this problem as it allows you to have flexible filtration media and you can choose what you find suitable.

  • Better durability and easier maintenance

Because of the entire design of a canister filter and the working process, the water having to pass through the filter media and not over or around it, makes them more easier to clean and low maintenance than other kinds of filters.

Durability depends upon the manufacturer and many of the best canister filters offer long warranties as they come from renowned and trustworthy companies from countries like Germany, Italy and USA and these filters have stood the test with thousands of successful field results.

  • Silent operation

Well, if you have ever used a hang on back filters you will have noticed the noise it makes and this is where a canister filter proves to be more effective. The canister filters are very quiet and they also do not provide the extra vibration as the hang on back filters.

  • Sleeker aesthetics

When it comes to hiding your equipment and making aquarium look sharper and sleeker there is rarely anything better in the filtration department than a canister filter. It hides your major pieces of filtration in your cabinet and you can work in an inline heater system for the heating of the tank without having to put an extra heater inside the tank. You also have the option of not having to run an air pump with the aeration that a canister filter can provide. Overall a canister filter minimises a lot of equipment and saves you a lot of space.

Best Canister Filters for your Aquarium

Below we have picked the best canister filters that are available in the market and we have discussed them, in brief, outlining their pros and cons.

Penn-Plax Cascade 700  Canister Filter

Penn Plax is an American company that has a very inspiring story behind it but the company is not just confined to it’s inspiring start-up. It is a very reliable and well-known name in the world of pet-owning a business. And the Cascade 700 comes from the long line of the family of canister filters. These are available in various sizes depending upon the tank volume ranging from 30 gallons, 65 gallons, 100 gallons, 150 gallons to the one we are talking about here, the Cascade 700 CCF5UL which filters a tank of up to 200 gallons.

It has the dimensions of 11.5 inches × 20.5 inches × 12 inches.

It has a 350 gallons per hour of flow rate which means that it can pass 350 gallons of water through the filter media in an hour providing with a large volume of filtrated water within that time frame.

It has five filter baskets. This large capacity of the media baskets allows the aquarists to customise the filtration media needs to their own requirements making it one of the most versatile canister filters. Additionally, it has a floss pad that helps in removing any particulate matter and also contains a coarse sponge which provides an abundant surface area for promoting beneficial bacterial growth that help in removing ammonia and nitrates. And all of this is included in with the purchase.

Well suppose if you have a tight space around your aquarium and even in those conditions the Cascade 700 obliges with the space as it has the flow valves which are easily rotatable 360 degrees and provide for an easy manoeuvring even in the tightest of aquarium cabinets.

The model comes with an easy push down button which rids you from the necessity of having to siphon the water into the filter to get it working. It has a priming button for exactly that purpose. If you push down the priming button for five to 10 minutes this makes the filter pump out all the air and start running so the filtration process can begin.

Another great design feature is that in it includes a spray bar, tubing, directional spout that allows you to customise the out flowing current of water. This lends you control over the water flow as some of the fish like a higher flow of water current while others prefer slower currents.

It is also quite easy to maintain and clean as the flow valves can be easily removed from the canister while your hoses, intake and output valves can remain in the aquarium.


  • The five filtration baskets provide multiple stages of filtration, from mechanical to chemical to biological filtration and they get all kinds of dirt out from the water.
  • It has a self priming button which helps you start the filtration process without actually having to pump water into the filter.
  • The base of the filter is rubberised which helps it keep firmly placed.
  • It is relatively cheap as compared to other options and provides a whole host of features.


  •  It consumes quite a lot of electricity as it runs on 27 Watts of power.
  • Cleaning the canister can be a bit tiresome work.

Fluval Fx4

Fluval, a well known company in the sector of aquarium equipment makes it’s first entry on our list with the FX4 canister filter.

It is a heavy duty filter as it works on aquariums upto sizes of a whooping 250 gallons. It also works great on tanks low to 75 gallons and provided that you have right kinds of fish, as low as a 50 gallon tank.

It has a nice round design and comes at the dimensions of 15.6 inches × 15.6 inches X 17.7 inches and weighs nearly at 18 pounds.

The FX4 was designed so as to bridge the gap between Fluval’s 406 canister filter and the FX-6  and it does that work just perfectly as it pumps out an astounding 700 US gallons of water per hour.

The way the FX4 has been designed offers it five stage filtration where the mechanical filtration is done on the outside removing any debris. After this the water passes through the biological media. And lastly, you have the option of adding chemical filtration of some kind at the bottom of the filter. Even after all of this when you open the filter you will notice that there is still some extra space left for more media which you can add depending upon your own needs. The filtration basket however does leave you wanting for more space.

It decreases the workload upon you as it offers a self priming button. The pump readjusts every 12 hours and the readjusting is quite loud.

It has another wonderful feature in the form of a purge valve which makes water changing a lot easier. The purge valve allows for the attachment of a hose that helps draining of water easily during water changes and rids you from having to bucket out the water with your hands.

It has Aqua stop  valves that are leak-proof and have Click Fit attachment system. The valves are positioned 45 degrees at angle for easy installation and rotation. The multi directional output nozzles help you to direct the water flow wherever you want to.

It is also quite easy to maintain and also to set up and the rubberised feet helps you to ensure that there is minimum vibration and noise.


  • It can be used for both fresh water as well as salt water.
  • It’s compact design means that it can fit almost anywhere.
  • It has easily manoeuvrable output nozzles that help you direct the water flow. 


  • It doesn’t come with a spray bar and you will have to buy it separately.
  • It is quiet expensive too.

Marineland Magniflow

The Marineland Magniflow comes in ranges of up to 30 gallons, 55 gallons and highest to up to 100 gallons. However, the one we are talking about here today is the one that works up to an aquarium of 30 gallons.

It is light weighing in at 10.58 pounds and has the dimensions of 12.2 inches × 9.2 inches × 13.6 inches making it a compact rectangular with slight taper towards the base unit.

This 30 gallon one has a filtration rate of 160 gallons per hour.

It offers a multi stage filtration system that catches all the debris an unwanted wastes from your freshwater as well as sea water aquarium quite easily. It has a filter foam for mechanical filtration that screens out such dirt and debris and the small bio filter balls and ceramic rings that provide a large, multi faceted surface area for the growth of beneficial nitrogen fixing bacteria. The Magnum 360 are the successors to the Magnum 350 which we criticised for not having enough media space options with the limited media space. This new and improved version addresses that issue as it has a stack and flow filter tree that keeps water flow from moving into the various stages prematurely.

Another upgrade from the older Magnus is that the canister lid has a quick latch on and off function that provides a better seal.


  • It comes with a 3 years long warranty making it hugely durable.
  • It has the auto shut off feature that makes it easy for quick cleaning.
  • It doesn’t make too much of a noise.


  • It does not have a valve switch to adjust water flow.
  • The older versions had diatom filter options for water polishing and ich management. The newer version omits that.

Hydor Professional External

This is Hydor’s first venture into the Canister filter department and it is trying to compete with the German manufacturers such as Ehiem and Fluval. Knowing that this is their first leap into this equipment, the result is definitely something you would want to know about.

The Hydor professional external canister filter comes in five different options ranging from the bottom most 150 version which works for 20 to 40 gallons of aquarium to the top most 600 version which we are talking about.

It works on an aquarium of the size ranging from 90 gallons to 250 gallons. It has a flow rate of 345 gallons per hour.

Like every other canister filter in our list, this too has five media trays and every model comes with complete filtration media, ceramic rings, filter pads. The only thing that is not included is carbon

The rectangular design features media trays that are completely flush against the sides which forces the water through the filtration media. The rectangular shape also allows it to hold more media then your average round shape.

It also features a priming bump that offers the versatility of using for both freshwater as well as salt water aquariums.

The unique point of this filter is the safety lock design that clamps the machine in place so that it doesn’t suffer a backlash from the power. It also features valves that don’t allow the water to flow back into the filtration chamber. The ball valves also allow you to adjust the flow of the water. And it also has rubber feet design that helps reduce the vibrations and noise.

It also comes with a two years warranty and can be a bit messy at times to clean and maintain as compared to other models.


  • The media chamber is adjustable.
  • The design which is rectangular and flatter allows it to be more eye friendly and stored easily.
  • The ball valves serve the purpose of adjusting water flow rate as well as not allowing water to enter the filtration chamber.


  • As compared to other mid range competitors, it is quiet a bit expensive.
  • It is also not the most noise free filter.

Ehiem Classic Canister Filter

The German giant EHIEM makes it’s first entry on our list with it’s Classic 250 or EHIEM Classic Canister Filter.

It comes in a variety of sizes from the lowest at aquariums up to 40 gallons to the largest at aquariums up to 92 gallons. Thee one we are talking about here is the midrange 66 gallon one.

It is the second  lightest canister filter featured in our list at just 4.5 pounds and expands 8 inches× 6.3 inches × 14 inches. This makes it compact and compatible.

It is also highly energy efficient, as expected from a German equipment as it consumes only 8 watts of power. For that small a power it has 116 gallons per hour of flow rate.

The filter comes packed with compatible and specifically designed Ehfisynth, Ehfisubstrate, Ehfifix and Ehfimech filtration media. However, these can cost quiet a bit to replace once you run out with the initial ones. The Ehfisubstrate provides with a large area for beneficial  bacterial that do the biological filtration. It has the classic one chamber design which allows you to dictate the amount of type of filter media you want in it, separating the media into layers using the provided pads.

Although the design and functioning is efficient bit it can also be quite underpowered for larger aquariums.

The fixed permo elastic silicone seal rings on the pump head allows for easy and safe closing after cleaning.


  • It is quiet, compact and efficient in operation.
  • The filter media comes included in the kit.
  • It does not include media trays which allows greater water flow and faster filtration.


  • The lack of media trays can also mean that it is quite difficult to clean.
  • It does not have any self priming feature or activated carbon.
  • EHIEM is famous for having quiet difficult to follow instructions in its manuals.

Fluval 206 External Canister Filter

The Italian giant Fluval make the second entry in our list.

This is the lightest canister filter on list at nearly 4 pounds of weight expanding 6 inches X 11.4 inches × 14.8 inches. This makes it highly compatible and easy to move.

It works wonderfully on tanks up to 45 gallons of volume and has a high flow rate of 206 gallons per hour.

It features the classic three stage filtration system with mechanical, biological, and chemical stages. The mechanical stage uses foam filter to absorb the debris ensuring any other media is not clogged with large pieces. The chemical and biological stages are independent modules and they can be easily replaced and removed without making too much of a mess. The filter already comes with foam pads, carbon, BioMax media included making it easy to use from the get go.

Another unique feature is the sound dampening impeller which means that this filter is much quieter than many others.

As with the previous FX4 this too contains the Aqua-Stop valve which makes it easier to connect and disconnect hoses with the external filter.

As with any other Fluval canister it comes with a three years of warranty.

It contains lift lock clamps that ensure you can just lift them to reach the filter for easy maintenance without having to worry about leaks. The multiple filtration brackets also allow you to take one basket out separately from the others and you don’t need to take them all out when you need to change just one, cutting off the hassle.


  • As with any other Fluval model, this too is quiet durable.
  • The sound dampening impeller makes this one of the quietest filters in the market.
  • The Fluval 206 is named after its GPH rate of 206 GPH which is quiet high and powerful.


  • With time, the quietness slowl0y starts to fade and it starts becoming louder and louder.
  • The output nozzle is quiet shaky and causes the water flow to move around quiet a bit.

Things To Consider Before Hand

Tank size and requirements

The first and foremost thing that you would want from your filter is that it fits the requirements and the physical parameters of your aquarium tank. Not every canister filter is made for tanks of all sizes. That is why you should carefully look at the listing on the packaging and see whether it can support your volume or not. Also you need to check the dimensions of the canister itself so you know where you can keep it and where you cannot.

Flow rate

The flow rate is measured in GPH which is the abbreviation for Gallons Per Hour. This means the amount of water that can pass through it per hour. The greater the GPH value the greater the amount of water that it can clean in an hour. At the first look it might seem beneficial to have as high a GPH as possible but you must also consider the fact that a higher GPH equals to a higher current of water when the water comes out of the filter and this may lead to greater disturbances in smaller tanks.

Flexible filter media selection

When you choose a Canister Filter, you want it to have a large media space so as to hold a large amount of filter media. This not only allows you for greater biological and chemical filtration but also allows you the freedom to add multiple types of media in it. You can add carbon, Chemi pure, phosphate removers and ammonia remover so as to make your unit even more efficient.

Easy maintenance and cleaning

Canister filters by design are easy to maintain and clean as they require the water to pass through the filtration media instead of passing around them or over them. But still, you will want to choose the option that does not require too much of a work or hassle for cleaning individual parts as a lacklustre cleaning job can affect the flow rate and future performance.

Quiet performance

If you are someone who likes to keep their aquarium as a show piece in the living room or as a source of calmness after a hard day at work, you will want the filter to make as less noise as possible. Some of the products we have on our list contains special features like dampening impellers that drown down the noise. Make sure you observe these features before committing to buy it.


How often do I need to clean my canister filter?

The answer to this question fairly depends upon the bio load and the type of fish you have in your aquarium. If you have more plants and fish like goldfish that make a lot of mess then you will want to clean up your canister frequently. However, even if you don’t have a hugely messy tank you will need to clean your filter at least once a month. The motor needs to be cleaned every three to six months to keep it running at the highest level but be careful about the biological filtration media as you may wash out the beneficial bacteria too.

Does the size of the canister matter?

Sadly, yes. Size does matter here. Ahem.

The rule of the thumb goes that the larger the canister, the more powerful it is. However, this is not a hard and fast rule. As you might have seen the Fluval 206 is one of the lightest  and smallest filter we have listed but still has a high GPH. Better thing to do is to check the power consumption and GPH rate before hand and not depend upon the size.

How do I set up a canister filter?

Identify the parts of the filter

Unpack and get your part listings. Check whether everything is present in the package or not. If you have your filter bundled with the media you’d want to check whether it is damaged or not.

Select a good spot and prepare your tank

You need to find the right spot for your filter so that all the equipment related does not hinder the aesthetic of the tank. It needs to be below the aquarium for the optimal use. Make sure that the hoses are directly connected to the tank and not wound up or tied in the middle.

Prepare your filter and install the media

Remove the motor head make sure all the media brackets are inside it. Then install the mechanical media in the first bracket as it collects all the debris and does not let the other media get clogged up. After that insert the biological media which will contain your beneficial bacteria. And lastly keep the chemical filtration media. You may have a little gap at the end which you can fill with ceramic rings to diffuse any waste that may be collected down there.

Prepare input and  output

After installing the media, install the intake and output hoses and make sure that there are no slacks or loops or knot.

Run the filter

After all of this has been done start your filter and make sure it is running properly by watching it work for 15 to 20 minutes. Make sure there are no leaks.

How does a canister filter work?

Well each and every individual product works in a separate way. But the whole idea that forms the backbone of a canister filter is that it works on a process known as the three stage filtration.

Water from the tank is sucked through the hoses and then it is passed through a canister which contains pressurised trays that contain filter media. Then the water in the canister goes through mechanical, biological and then chemical filtration chronologically. The mechanical filtration removes the physical impurities and debris, The biological filtration Is the part where the beneficial bacteria convert the harmful ammonia into less harmful form of nitrite and the chemical filtration involves the direct injection of various chemicals to remove the impurities.

The purified water is then pumped back into the tank through the output hose.

Canister filters are different from others in this regard that the water has to pass through the filtration media and not around it or over it.


So, as we have seen Canister filters offer you with some unique mechanism of cleaning the water and are  very necessary equipment for a clean and clear aquarium. Many options available in the market and every product on our list can suit your tank according to your requirement. However if we have to choose one overall, we would choose the Penn Plax Cascade 700 as the best all rounder in its class.

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