Selecting the best canister filter for your home aquarium is an important decision since filtration plays such an integral role in the health and maintenance of your tank.
Choosing one requires that you understand the advantages of this particular style filter as compared with other styles, and know whether it’s appropriate for your tank size.
Selecting one is also made easier by looking the most popular canister filters side by side.
- Advantages of Using Canister Filters
- Determining if a Canister Filter is Appropriate for Your Tank
- The Reviews of Top Rated Products
- 1. Penn Plax Cascade Canister Aquarium Filter
- 2. Fluval External Filter
- 3. Aquatop CF Series Canister Filter
- 4. Marineland Multi-Stage Canister Filter, C-Series
- 5. Hydor Professional External Canister Filter
- 6. EHEIM Classic External Canister Filter with Media
- 7. EHEIM Ecco Pro External Canister Filter with Media
Advantages of Using Canister Filters
The versatility and reliability of canister filters yields many advantages compared to using other styles of aquarium filters.
The biggest benefits are explained below:
Less CO2 disruption
Because canister filters are external to the tank they cause no surface agitation like a hang-on-back (HOB) filter would. Surface agitation is great for increasing oxygen, but can deplete the CO2 that’s present. Heavily planted aquariums need that CO2 to get better growth.
High flow rate
Canister filters are capable of much higher flow rates than their internal counterparts. Higher flow rates translate into the entire tank being cleaned several times each hour, and better prevention of dead zones. The result is that your tank is as clean and healthy as possible.
Large filter media capacity
Canister filters accommodate any combination of biological, chemical, and mechanical filtration.
Click here to view more about filtration types.
Additionally, their large media baskets ensure that the aquarium water makes sufficient contact with the media to remove impurities. They’re made to filter large amounts of water so you’re not having to change media as frequently as other filters.
While most people find the sound of trickling water to be appealing, few enjoy the droning sound of the filter motor moving water through the system. With canister filters, you don’t have to worry about that. They’re quieter than others for two reasons: they’re usually stored behind a cabinet, and the motors are tightly sealed. The motor is impervious to dust, and requires very little maintenance.
Saves tank space
Tank space occupied by a filter is space that can’t be used by fish or plants. This isn’t a problem with canister filters since they are setup outside the tank. The only parts of the filter that go inside the tank are the tubes.
Easy to get started
Canister filters are easy to start using; set-up consists of little more than connecting your hose, adding media, then priming and powering on. It used to be that priming was the most time-consuming step, but now most units come with a self-priming feature that shaves time.
Maintaining a canister filter can be done without disturbing your tank occupants. Because it’s external you don’t have to worry about moving housing or plants, nor have to be concerned about a potential mess.
Lots of accessories
Canister filters can be used on their own or paired with a number of items to meet the needs of your specific tank. The system can be expanded to include advanced filtration with UV sterilizers. And the flow can be customized by adding spray bars.
Determining if a Canister Filter is Appropriate for Your Tank
Generally, canister filters are most appropriate for tanks over 25 gallons because they can move so much water. Tanks less than 25 gallons can be sustained with internal power filters or hang on back filters.
The larger, heavily populated tanks would strain internal power filters. These tanks require large media baskets and extended contact time with the media that the internal and HOB filters can’t accommodate. Canister filters are also easier to access and operate, plus they’re customizable.
For canister filters to keep your tank clean, all of the water must pass through the filter several times each hour. A good rule of thumb is to multiply your tank’s volume by four, and that’s the size filter you need to get. For example, if you have a 50 gallon tank then you need a filter that moves at least 200 gallons of water per hour.
When the number is borderline make sure to choose the filter with a higher flow rate. For example, if your filter choices were between one that moved 150 gallons per hour and another that moved 250… you’d choose the 250 gallon one.
The Reviews of Top Rated Products
1. Penn Plax Cascade Canister Aquarium Filter
The Cascade Canister by Penn Plax comes in five sizes to accommodate tanks from 30 to 200 gallons in size. It offers a sturdy compact design and easy-to-use configuration. The three-year manufacturer’s warranty is a nice touch as well.
Cascade filters are built from hard plastic and take up very little cabinet space. They strike a good balance between weight and durability; the plastic casing keeps the unit light enough to pick up but strong enough to last a long time. Rubber feet attached to the bottom of the base ensure that it won’t be easily knocked over or jostled.
Each unit includes a handle on top to make transport as quick and simple as possible. Disassembling then reassembling the unit is also quick because of alignment clamps on either side of the filter. There’s no time wasted by accidentally putting the top on the wrong way; the alignment clamps ensure you’ve got it right the first time.
Penn Plax pre-installs the filter media into its canisters. This speeds up the initial set-up and shows you what order the media should go in.
#Penn Plax Cascade Canister Filter
-Easy to setup & maintain9.0/10
- Quiet and easy to clean and change filter media
- The containers that hold the media are pretty solid
- Priming the filter after each cleaning is quick and easy
- Require minimal maintenance to keep running smoothly
- Filter pads could be better quality
- The intake tubing that comes with it could be longer
- Small units come with very few media baskets
Overall, Cascade Canister Filters are an above-average filter with great features. It’s strong, handles a variety of media, and sets up easily.
The 06 series of canister filters by Fluval have a more powerful motor than its predecessors, and packs in many user-friendly features like adjustable flow rates, and single-motion locking clamps.
Models of Fluval’s 05 series had trouble handling sustained water flow so Fluval increased the power on this series. At the same time, they made it more efficient; using less energy than other similar motors.
Water taken through the intake tube follows specific pattern through the filter to allow maximum contact time with the filter media. Their filters also hold about 40% more water than round ones of similar size.
The unit is constructed of heavy-duty plastic with each stage of filtration kept separate from the others. Patented valves let you stop water flow without disconnecting hoses, and is equipped with a self-priming function. The whole unit is tightly sealed to prevent leaks.
The baskets come pre-filled with media to make set-up quick. It also has clog-proof intake strainer and two-layer foam screen for more efficient mechanical filtration.
#Fluval External Filter
-Easy to setup & maintain8.0/10
- The units are easy to clean by removing the top then using the one-motion locking clamps to resecure it
- Pump is superbly quiet and nearly impossible to hear
- Minimal maintenance needed to keep unit functioning correctly
- Larger models don't come with a spray bar to spread out the returning clean water
These filters are most appropriate for small to mid-sized home aquariums.
3. Aquatop CF Series Canister Filter
The CF Series filter by Aquatop is a budget-conscious machine that’s largely easy to use and offers a nice UV feature.
This is a compact lightweight unit that easily fits underneath a cabinet. It’s constructed of standard quality plastic and feels a tad flimsy. Indeed, some users note that the o-rings are prone to leaks because the pieces don’t seat well together. The company suggests that using only Aquatop branded products inside their filter will help prevent such leaks.
The package includes all of the necessary plumbing you need to get up and running. The hoses, inlet, and outlet are all good quality.
Media compartments are sufficient to accommodate three methods of filtration. They’re large enough to hold quite a bit of filter media. Unfortunately, it doesn’t come pre-filled but it does come with a few sponges, some activated carbon, ceramic rings, or Bio-balls.
Setting up the unit can be difficult for new users. The written directions are confusing but several video tutorials exist online that can walk you through the process.
The CF Series operates very quietly and very effectively. You can’t hear it running when it’s located behind a cabinet door. The water it outputs is sufficiently clean.
#Aquatop CF Series Canister Filter
-Easy to setup & maintain8.5/10
- The manually-powered UV light is a nice option to have for those rare times your tank experiences a problem with bacteria or algae
- The intake pipe is adjustable to any direction to fit into any aquarium set-up
- It has no purge valve or handle so it's difficult to move and clean
- It can be difficult to prime this unit
Overall, the CF Series by Aquatop is a decent filter though more durable options exist. It’s a good unit to use as backup if the primary filter is out for repairs.
4. Marineland Multi-Stage Canister Filter, C-Series
The C-Series Multi-Stage Filter by Marineland is a well-designed unit that holds a respectable amount of media, though some components could be better constructed.
Marineland designed the unit well although the quality of the materials could be better. It’s got a sleek narrow profile that fits just about anywhere, but is constructed of a thin plastic housing and plastic fasteners. It’s extremely easy to over tightened the plastic screws that hold the hoses. The seals around the motor feel loose, but very few leaks are reported in that area.
Media baskets separate each series of filtration so there is no water bypass. It does take a bit of work to ensure that the gasket around the media baskets is sealed well but the baskets are generously sized. There’s a lot of room for water to contact the media and filtration to take place at each level. It comes with ceramic rings, bio-balls, filter foam, and carbon included in the package.
The hoses are large and can be difficult to work with but running them under hot water softens them up and makes them pliable. They’re also very thick and difficult to cut with regular scissors. The valve can be a tricky and likes to stick in position.
#Marineland Multi-Stage Canister Filter C-Series
-Easy to setup & maintain8.0/10
- It's easy to open to complete maintenance. Disassembling and reassembling goes quick; you just have to make sure everything is tightly joined and sealed.
- Quick-prime button fills canister quickly so you can use the self-priming system.
- This filter operates more noisily than others, likely due to thin construction not buffering the sound.
- The written instructions could be more clear but the DVD and online tutorials help with set-up
Overall, Marineland’s C-Series Multi-Stage Filter is an acceptable product. It gets the job done, though some people have to spend extra time ensuring that it seals.
Hydor’s Professional External Canister Filter is built well and reliable, making it a good addition to any aquarium.
It’s constructed of strong plastic components that fit well together and has safety locks to ensure a good seal.
Setting up the filter is incredibly easy; the directions are well-written and the parts fit together nicely. The package includes starter media so you pretty much just fill your media baskets, cut the tubing to size, then prime the system. The only thing it doesn’t come with is carbon.
The media is separated into trays that are sealed around their edges to prevent water from bypassing any level of filtration. In practice, this system works exactly as intended. The water benefits from full contact with each series of filtration.
Hydor provides ample tubing to accommodate any plumbing configuration. The tubing is flexible yet durable; not stiff like cheap hose. It also has an expandable spraybar that you can customize to fit your tank.
#Hydor Professional Canister Filter
Overall, the Hydor Professional External Canister Filter is a strong reliable machine and a good value.
EHEIM’s Classic filter is built well, sturdy. It’s mainly constructed of tough plastic; the filter clips are soft metal that bends easily.
The configuration of the EHEIM Classic is simple, the filter media isn’t kept in separate baskets. You put it all into the main compartment of the filter. The inlet and outlet tubes are on opposite sides of the filter helping to ensure that the clean and dirty water don’t mix.
It comes with all the filter media and tubing you need to set up the filter for the first time. One thing to consider when putting it together is that the tubing doesn’t come pre-cut, rather, it comes as one long piece.
The tubing is green to prevent algae build-up and is UV resistant. Some people find the green distracting and note that the color makes it difficult to see if the lines have build-up.
Once up and running the motor is nearly silent. The ceramic impeller shaft is fragile though, care needs to be taken not to crack it during the cleaning process.
It does have strong output from the spray bar, but the bar could be longer to spread out the flow more.
#EHEIM Classic External Canister Filter
-Easy to setup & maintain7.0/10
- The tubes are pliable and easy to work with
- The included filter media is good quality
- The instruction booklet is confusing, especially if you’re new to canister filters. But online video tutorials will help you get that job done
- The instruction booklet is confusing, especially if you’re new to canister filters. But online video tutorials will help you get that job done
7. EHEIM Ecco Pro External Canister Filter with Media
The Ecco is easy to set up, especially if you use the quick-start directions. Everything you need is included in the package: tubing, media, valves. Green tubing can make it difficult to see if debris or films have developed inside. It doesn’t come with a spray bar, instead, it’s got an adjustable nozzle.
Disassembling the unit for cleaning is easy but you have to take care during reassembly not to crack the components. It’s constructed from very rigid thin plastic similar to that of CD cases. It’s got an integrated o-ring at the joint that seals the unit together.
The quick-release for the pump head makes it easy to get to the media baskets. The inlet/outlet pipes can do a 360 degree swivel making it much easier to position the tubing from the filter to the aquarium.
It features interlocking media baskets to prevent water bypass and ensure water stays in contact with each filter layer of media. Each media basket holds a sufficient amount of media so that you can fill them with whatever media you want.
EHEIM boasts a patent-pending multifunctional handle that is supposed to be used for priming the unit, carrying the unit, and for opening and closing. It’s a great idea in theory but prone to failure. Most users recommend not carrying the unit by the handle.
#EHEIM Ecco Pro External Canister Filter with Media
EHEIM Ecco is a strong unit that gets the job done but could be constructed better for long-term use.
The table below summarizes some important features for 7 canister filters above. Use it as a quick reference to help you determine which model meets the needs of your tank.
Things to Consider When Choosing and Setting Up a Canister Filter
Once you’ve decided that canister filters are the right type of filter there are a few extra things you need to consider.
How canister filters work
Canister filters use high pressure to force water through a container of filter media; clean water is then dispensed back into the aquarium. It sounds more complicated than it is.
Before you can understand how one works it’s helpful to know what it looks like. Typically canister filters are constructed of a plastic container that has two tubes sticking out of it. The tubes may be together, or they could be in separate places, like one at the top and one at the bottom.
You’ll also usually find a pump built into to the canister; it’ll be in the base or the top cover. But some models require a separate pump.
Here’s how it all works together to keep your tank clean:
1. The pump draws water into the plastic container, the canister, through one of those tubes. Inside the container is the material that filters out impurities.
2. Water is pushed through the media.
3. Clean water is then enters back into the aquarium through the other tube.
GPH is the acronym for gallons per hour and is a measurement of your filter’s flow rate. It’s an important measurement. Without it you won’t know if you’re filtering enough water to keep your tank clean, and your plants and animals healthy. In general you want a flow rate of at least 3 to 4 times the tank size. For example, if you have a 10 gallon tank you’d want to make sure you achieve a rate off 30GPH.
Consider the contents of your tank when looking at flow rates. Some fish and plants prefer a stronger current than others. Highly populated tanks that produce more waste also need pumps with a high flow rate. You’ll need to research the needs of your plants and animals before settling on a specific model of filter.
Creating proper water flow
Water flow is very important to the overall health of your tank and its inhabitants. Proper water flow ensures a clean environment by regulating pH and oxygen, and gives your fish mental stimulation by reproducing natural water movement.
You want your water to flow smoothly through the tank; like a river instead of the rapids. Good water flow is easy to achieve if you set up your intake and outtake tube correctly. In a rectangular tank this pattern usually resembles a circle.
Below is a tip to create proper water flow for your aquarium:
1. Make sure to start by placing your intake and outtake tubes on the same side of the tank.
2. Position your intake tube a few inches above your tank’s substrate. This helps lift waste water instead of just moving it sideways along the bottom.
3. Positioning your outtake tube is the most important part of creating proper water flow because it determines the flow pattern… that circle we want to achieve.
4. Remember, the position of the outflow rather than the type of outflow. You can use Lily pipe or regular pipe.
5. Position your outflow tube so that the flow angles downward but not so much that there is no flow at the surface. This may take some trial and error to find the right depth. There’s no universal depth that works because it depends on the size of the tank.
Volume of Filtration Media
Having the right amount of filtration media is important because too much media will be too dense for water to flow through, but not enough media fails to properly clean the tank. Most filter units will come with directions, as will the media you decide to use.
A good rule of thumb though is to use media bags and fill them so that they feel like slightly firm pillows.
Knowing if It’s Working
A functioning filter shouldn’t be noisy. It’s common to hear a slight hum from the pump, or the gentle sound of flooding water, but you shouldn’t hear rattling or swishing noises.
Noisy filters could be a sign that the unit is broken, misaligned, or needs the media changed.
Power outages aren’t fun, but the experience worsens if your filter can’t automatically start functioning once power comes back on. For this reason, self-priming function is a nice feature on your canister filter.
Self-priming systems allow a bit of water to remain in the system when power is unexpectedly cut. This lets the pump resume normal function once it returns, without it water couldn’t enter the system until you manually refilled the pump.
UV sterilization installed after your biological and mechanical filtration helps prevent algae blooms and microbial overgrowth that cause green water. Pathogens aren’t immediately killed by UV rays, for them to work you need to make sure that the water flow is controlled so that it stays in contact with light long enough to work.
Make sure to measure the space where you intend to store your new equipment. And take into consideration the amount of room you’ll need for tubing.
You want the filter set up as close to the tank as possible so that the filter doesn’t have to move the water very far. The farther the water has to travel, the stronger your pump needs to be.
Cleaning and Maintenance
A filter can only perform well if it and the tank are properly maintained. It will last longer and clean the water better.
Your maintenance schedule largely depends on the size of your tank, and how many living creatures live in it. For example, a large tank with few fish would need less frequent maintenance than one of equal size that contains a reef, several fish, and other plants.
But there are some universal suggestions that will help keep your unit clean and safe:
1. Remove algae and other debris from the tank and from the filter’s inlets.
2. Visually check water flow; if it slows down then you have a problem.
3. Check the outside of the canister for leaks.
4. Disassemble the filter to and clean it thoroughly.
5. Change the filtration media periodically.
6. Filter sponges should be changed when they change shape or start breaking down.
7. Use only specially formulated aquarium cleaners. Cleaning agents are dangerous to the fish and plants.