Canister filters are one of the most efficient filtration systems available for aquariums and one of the best ways to ensure an optimal environment for your fish to thrive in.
They’re recommended for tanks both large and small, and suitable for everyone from the amateur hobbyist up to enthusiastic expert fish keepers.
Depending on make, model and what filtration media you decide to use, biological, chemical and mechanical filtration are possible with a canister filter.
So crystal clear and healthy water can easily be achieved with a quality model.
- The Practicalities of Owning a Canister Filter
- What Types of Tank and Fish are Canister Filters Suitable For?
- How Big Are They?
- How Long Does a Canister Filter Last?
- How Much Maintenance is Needed?
- What Should I Be Looking For When Buying a Canister Filter?
- To Sum Up
- Top 5 Best Canister Filters – Our Picks
The Practicalities of Owning a Canister Filter
How do They Work?
In short, canister filters work by continually pumping water out from the tank into the canister and running it through various stages of filtration media in order to purify it before pushing it back out into the tank.
What are The Advantages of a Canister Filter Over Other Types?
Canister filters are significantly bigger and more robust than other types of filter such as internal or ‘hang-on-back’ (HOB) filters.
They last longer, provide more powerful filtration and require less maintenance to function effectively.
Where other filters may only be suited to a particular aquarium type, size or breed of fish, the best canister filters are a good choice regardless of tank size and inhabitants. Quality models will also fit both fresh and saltwater habitats.
Due to their size and power, canister filters are highly efficient in comparison to other filter types, as they’re able to filter a large amount of water quickly, reducing waste in the tank much faster.
They offer an owner the chance to customize the internal filter media, allowing any combination of biological, mechanical and chemical filtration desired, to match the exact requirements of your aquarium or what you are currently trying to achieve.
Aesthetically, canisters are preferable to the intrusive ‘hang-on’ filters as they are usually stored externally – say in a nearby cupboard, hidden inside the cabinet supporting a tank as a stand or on a shelf.
They also run very quietly so won’t prove a disturbance in quieter rooms or spaces.
Comparatively, canister filters are more expensive than other types of filter – depending on the make and model – but are generally considered to be good value for money as they have a long shelf-life and offer superior cleaning and filtration.
What Types of Tank and Fish are Canister Filters Suitable For?
Although a canister filter would probably be considered overkill for a very small aquarium (say, a 5-gallon fish bowl), they are a worthy addition to any decent tank from small to large.
Depending on your aquarium size, you can buy different sized canisters with corresponding flow rates to best suit the size of different tanks.
Canister filters are also a good choice regardless of whether you have a freshwater or saltwater aquarium. Just be mindful to check if the EXACT model you’re buying is best suited for one or the other in order to guarantee its longevity.
How Big Are They?
Sizes vary from model to model and many companies offer a range of canister sizes to fit different sized aquariums. The bigger the aquarium, the bigger the canister required is the general rule of thumb.
Before buying a filter, check the Amazon listing for the specific dimensions of individual models to make sure it fits in the space you have allocated for it.
How Long Does a Canister Filter Last?
The longevity of canister filters really does depend on how well they are looked after and maintained.
If you follow a good maintenance routine and are willing to buy new parts as and needed, then they can last in excess of a decade.
How Much Maintenance is Needed?
The impeller motor, rings and rubber gaskets are the most likely parts to wear out and require replacing but all are easily and affordably obtained from pet supply stores and, of course, the Internet.
Maintaining canister filters is generally easy depending on the model, although you will need to commit to cleaning and replacing the filtration media occasionally to guarantee the efficiency of the filter.
As with any filter, you will need to replace any carbon regularly as it can release toxins if it gets too clogged with waste. See the guidance of individual filters and media to get a firmer idea of replacement times.
The tubes and pump of the canister will also need regular cleaning between once and three times a year – again, check your particular filter’s own guidance. Cleaning kits may be included with the canister filter or you can easily obtain one online or at most local pet stores.
What Should I Be Looking For When Buying a Canister Filter?
You’ll need to consider the following features:
- The functionality: Is it suitable for freshwater or saltwater tanks? Or both?
- Size and flow rate: Ensure that the canister is big enough for your aquarium; they are priced and sized according to gallon-capacity. Good filters will filter the aquarium’s volume around four times in the space of an hour; so that would be 120gph (gallons per hour) for a 30-gallon tank, say.
- Whether a pump or self-primer included: Canisters work by pressurising water into the filter through the use of a pump. While most models will include one automatically, cheaper models may have you buy one separately or you will need to siphon the water manually.
- Ease of maintenance: Check how easy it is to install, how often it’s recommended you clean the product and how readily available the replacement parts are.
- Is there any filtration media included: Check if it comes already equipped with biological, chemical and mechanical media.
- How customizable is it: Are you able to pack and stack the media as you desire? Is the flow rate adjustable?
- Accessories – Are there any available?: For instance – diatomic sleeves, sponges, extra rings for additional filtration, a spray bar, intake strainer and spare tubing.
To Sum Up
Canister filters are used by smart fish keepers who want the best filtration possible and to be able to customize the mix of filtration media held in the internal baskets to suit their specific tank.
They are the best type of filter available and the type of filter we most recommend on this site.
Top 5 Best Canister Filters – Our Picks
We’ve used many a filter ourselves and have scoured the internet for reviews and information on dozens of different models, looked at the pros and cons of each and picked the best 5 models to show you below.
Fluval External Filter
Fluval are one of the best known and best respected aquarium filter brands available.
This external filter is available in four different sizes; up to 25 gallons with 145gph, up to 45 gallons with 206gph, up to 70 gallons with 303gph and up to 100 gallons with 383gph.
The x06 range comes complete with hoses and hardware to hook it all up as well as biological, mechanical and chemical filtration supplied in the internal baskets and so is ready to go when shipped, no other accessories required.
The Fluval x06 range has the perfect blend of price and features, an efficient and ready to go complete kit Not the cheapest but far from the most expensive. What you get for the price makes these the best canister filter choice for most people in our opinion.
They are suitable for both freshwater and saltwater aquariums.
- It has multiple and removable filtration baskets for you to customize the filtration process, and comes with mechanical, chemical and biological media.
- With a clog-proof intake strainer and double layer foam screen, more debris is absorbed quicker.
- A complex water flow path means that the aquarium’s water enjoys maximum contact with the media so is more efficiently and minutely filtered.
- It holds 35 to 50% more water than similarly sized round canisters, so water is filtered quicker.
- It is suitable for both freshwater and saltwater tanks.
- It runs very quietly with its special sound-dampening motor impeller design.
- It’s very sturdy and equipped with an Aquastop valve, lift lock clamps, class fibers and rim connector assemblies. Fluval are so confident of its quality that they offer a 3-year warranty on the product.
- Start-up is instant with a self-primer.
- Maintenance is easy too as the filter opens easily and quickly clamps down to lock.
- It has an adjustable flow rate.
- It comes ready to work straight out of the box – there’s no need to buy any extras.
- The color of the intake tube and seals is white, showing up grime and algae residue easily.
EHEIM Classic External Canister Filter With Media
EHEIM are another big name in the canister filter world and this ‘Classic’ model has been providing dependable filtration to thousands since it’s initial release 3 decades ago.
This model is available in the following sizes: For up to 40-gallon tanks, up to 66 gallons and up to 92 gallons.
- It’s a very efficient model with constant water circulation around the huge canister chamber and no bypassing of any of the multi-stage filtration.
- The filter pads and carbon pick up both coarse and fine debris quickly and efficiently.
- It’s a high quality, heavy-duty product with easy and safe closing and a leak-proof permo-elastic silicon-sealing ring on the pump head.
- It comes with a host of accessories: namely, a spray bar, filter sponges, inlet pipe, valves, tubing and a hose.
- It also comes with mechanical and biological filtration media.
- It runs more or less silently.
- It’s very compact in size and is rendered tip-proof by its stand.
- It works with salt and freshwater tanks.
- You can’t adjust the flow rate although you can adjust the direction and reduce the strength of the current with the included spray bar.
- Many users have complained about the poor instructions that come with the model – it’s best to check out a YouTube video to ensure set-up is done correctly! (Though it really is not difficult!)
Cascade CCF3UL Canister Filter
This Cascade canister comes in five different sizes: up to 30 gallons and 115gph, up to 65 gallons and 185gph, up to 100 gallons and 265gph, up to 150 gallons and 315gph, and up to 200 gallons and 350gph.
- It offers multistage filtration with large stackable trays of mechanical, chemical and biological media so you can customize as you see fit.
- Mechanical, chemical and biological filter media are included.
- You can adjust the water flow rate with the included cut-off valves and quick-disconnect tubing.
- It also comes with a spray bar so you can adjust the direction of the current.
- It self-primes easily so there’s no need for manual siphoning during installation.
- It’s very sturdy with a tip-proof base, locking clamps and a motorhead with an integrated o-ring.
- It runs very quietly.
- The included tubing is quite stiff so may require some elbow grease when it comes to connecting and installing the filter.
- There are no instructions included for how to disassemble the product so maintenance for the first time may require a little concentration. (Again, check youtube, there’s always help to be found there 🙂 )
Marineland C-Series Multi-Stage Canister Filter
For serious fish keepers, the Marineland C-Series offer a number of effective canister filters in the following sizes: up to 30 gallons with 160gph, 30 to 55 gallons with 220gph, 55 to 100 gallons with 360gph, and 100 to 150 gallons with 530gph.
- It boasts the most powerful flow rate of our top 5 models, meaning quicker filtration.
- It has a 3-stage filtration process with biological, chemical and mechanical filter media included.
- There’s no bypass option and a 100% water to media contact rate, ensuring crystal clear water and the effective removal of odors, discoloration and impurities.
- The media slots are replaceable and it comes with stackable trays so you can customize the filtration method to your own preferences.
- It primes instantly with no need for manual siphoning.
- It has an intuitive set-up and disassembly with printed instructions and a DVD.
- Everything needed for set-up is included in the box.
- The filter requires little in the way of maintenance: the ceramic rings and BIO filter balls only need replacing if they get damaged while the activated carbon and polishing pads should be replaced monthly. Cleaning the filter is easy with lift lock clamps, an intake strainer and heavy duty hoses.
- It works in both freshwater and saltwater tanks.
- It’s very sturdy yet runs quietly.
- Some users reported that in order to avoid air leaks, they had to use silicone grease to lubricate the gaskets. (A rare complaint, but one that needs highlighting!)
SunSun HW-302 3-Stage External Canister Filter
SunSun’s no-frills canister filter is very cheap in comparison to its competitors while still providing an excellent level of filtration.
It is available in just one size: up to 75 gallons with a 265gph flow rate.
- It is incredibly good value in comparison to other canister filters on the market while still offering a high standard of filtration.
- It has 3 large media trays to allow for biological, chemical and mechanical filtration according to your own preference.
- It comes with filter pads and hoses for a quick and easy setup.
- There is also a self-priming pump.
- It runs quietly and efficiently.
- It comes with an adjustable spray bar so you can adjust the direction of the current.
- You will need to buy biological, chemical and mechanical filter media separately. (Though for a small additional cost there is a kit available).
- The set-up instructions are quite generic – though again, it’s not difficult to set up..
- As a consequence of the lower price, the plastic structure feels a little less sturdy than its competitors.
While all of the canister filters we’ve reviewed above are of a high quality and will provide excellent filtration for aquariums both large and small:
The clear winner is undoubtedly the Fluval External Filter.
Its level of filtration is unparalleled with such innovations as a complex flow path, multiple, customizable filtration baskets, an adjustable flow rate, large capacity and unsurpassed ability to catch debris.
It’s easy to install and maintain, and is supremely sturdy with a guarantee for longevity to boot.
The Fluval is ready to go out of the box and comes equipped with high-quality filter media. You know you’re choosing quality when you opt for a Fluval and the model’s reams of satisfied customers speak for themselves. It’s our top recommendation!
Happy fish keeping!
image credits: © Amazon.com