There are many different kinds of aquarium filters to keep your fish tank’s water healthy and clean. You may prefer to run more than one kind of filter for optimal results. And the fish tank filter you need will depend on how many fish you have and the size of their aquarium.
Top fish tank filters
Let’s begin with reviews of the top aquarium filters for fresh and saltwater tanks. Below the reviews, we’ll discuss the different kinds of filters and how to choose the best one for your fish tank.
#1 Aqueon Quietflow Internal Power Filter for small aquariums
If you have a small aquarium that holds ten gallons of water or less, the Aqueon QuietFlow Internal Power Filter is an inexpensive investment that doesn’t require much upkeep. It comes with a limited lifetime warranty and only uses one replaceable cartridge.
The filter can be fully submerged in water in either a horizontal or vertical position. You can adjust both the flow rate and the direction and height of the water return, which is handy when you don’t want to stress the fish. And the three-stage filtration removes ammonia, nitrates, and other toxins, plus odors and discoloration.
#2 Tetra Whisper EX Silent Multi-Stage Power Filter for Aquariums
Tetra’s Whisper EX Silent Power Filter is a HOB or hang-on-back filter. It’s available in various sizes, from 10-gallon to 70-gallon tanks. And it comes with a Timestrip that reveals when it’s time to change the carbon insert.
#3 Fluval Underwater Filter for small tanks
Fluval’s Underwater Filter is versatile enough to create customized currents or a waterfall in your fish tank or reptile terrarium. It’s a good choice as a supplemental filter or the primary filter for up to a 40-gallon tank. And it operates silently.
The three-stage system comes with the BioMax biological filter, two foam pads, and two poly/carbon cartridges. You can adjust the circulation pattern and oxygenation levels with the top output setting. And if you have plants in your aquarium, you can protect them from too much flow with the integrated spray bar.
#4 Corner Filter Aquarium Fish Tank Internal Air Driven Filter with Media XY-2008 from AQUAPAPA for small tanks
Even little fish tanks deserve a reliable filtration system. This small internal air-driven filter handles up to 10 gallons of water. It fits neatly into the corner of your tank. And it’s very easy to clean and manage.
It relies on bubbles of air from an external air pump to move water through three filters. The top level is a sponge that removes debris and needs to be rinsed once every 2 to 4 weeks. The middle level is where the bacteria that break down ammonia thrive. It’s also a sponge that will need to be rinsed on occasion. Then the bottom level contains gravel that also supports colonies of beneficial bacteria.
#5 Water & Wood New 2-in-1 Underwater Air Driven Corner Filter for medium tanks
You may notice some similarities between this filter and the one described above. By doubling the layers of filters, this system can clean up to 40 gallons of water.
#6 Fluval C Power Filter for medium-size aquariums
The Fluval C Power Filter moves 153 gallons of water per hour through a five-stage filtration system. It’s recommended for aquariums that hold between 20 to 50 gallons. And it has an indicator to show you when it’s time to perform maintenance.
This clip-on filter requires a bit of work for best performance. For example, you’ll need to replace the activated carbon cartridge every 2 to 4 weeks, and the foam cartridge every 4 to 6 weeks. But in return, it keeps the aquarium water free from impurities, debris, odors, and discoloration. Plus, its biological C-Nodes system allows beneficial bacteria to flourish.
#7 Marineland Penguin Power Filter w/ Multi-Stage Filtration for medium tanks
The Penguin Power Filter offers mechanical, chemical, and biological water filtration. It relies on Black Diamond Premium Activated Carbon and the BIO-Wheel to remove nitrites and ammonia. And with the flow rate of 200 gallons per hour, it suits aquariums up to 50 gallons in size.
#8 Whisper In-Tank Filter with BioScrubber for small to medium aquariums
Whisper’s In-Tank Filter mounts inside your aquarium or terrarium for silent operation. It comes with a hanger and suction cups. And it only requires one replaceable cartridge.
The smallest Whisper filter fits aquariums up to 10 gallons, but there are other systems for tanks up to 40 gallons. They function in as little as 2 inches of water.
#9 Fluval External Filter 406 Canister for large aquariums
The Fluval External Canister Filter cleans aquariums up to 200 gallons in size with a flow rate of 383 US gallons per hour. And it works in both fresh and saltwater tanks.
Fans of the Fluval filter like that it’s quiet while operating, and easy to set up and maintain. Inside there are mechanical, chemical, and biological filtration baskets. With the patented Aqua-Stop Valve, it’s easy to disconnect the hose and perform routine cleaning.
#10 Marineland Magnum Polishing Internal Canister Filter (ML90770) for large tanks
If you have fish that require crystal-clear water, try the Marineland Magnum Polishing Internal Canister Filter. It filters up to 290 gallons per hour, which means it suited for aquariums up to 97 gallons in size. And it never needs to be primed because the motor is under water.
There are four filtration levels: mechanical, chemical, biological, and polishing. First, the floss sleeve captures debris, so it will need to be rinsed or replaced each month. Second, the activated carbon filter removes odors and impurities, and will also need to be replaced each month. Third, the two-chamber design of the biological filter encourages the growth of Spira, the beneficial bacteria that gets rid of ammonia and nitrites. And fourth, the filter “polishes” the water with a reusable micron cartridge you can fill with diatomaceous earth.
#11 AquaClear Power Filter for various tank sizes
AquaClear’s Power Filter is available in a variety of sizes, from 10-gallon fish tanks up to 110-gallon aquariums. If the size of your aquarium is near the cutoff for the next largest filter, but you have a lot of fish, always choose the more powerful system. And with AquaClear’s efficient filtration, you won’t spend a lot of money on electricity.
One of the advantages is a feature called BioMax that removes ammonia and nitrates, plus maintains a colony of healthy bacteria. But the system also removes debris with foam and odors and with activated carbon. Each one of AquaClear’s filters is covered by a two-year warranty.
#12 Marineland Emperor 400 Pro Series Bio-wheel Power Filter for large tanks
Marineland’s Emperor 400 Pro Series fits aquariums up to 80 gallons with its two pumps and a flow rate of 400 gallons per hour. It uses two filter cartridges at a time. And it has the effective BIO-Wheel wet-dry biological filter system, too.
#13 Cobalt Aquatics EXT Canister Filter
Cobalt Aquatics’ EXT Canister Filter never needs to be primed because it doesn’t rely on gravity. You can position it beside, above, or below your aquarium. And it has a unique feature that allows the pump to run while you disconnect the canister for maintenance.
Maintenance of a filtration system is essential, but if it’s a hassle, you’re likely to put it off. That’s why the EXT filter is a good choice for the procrastinating aquarist. All you need to do is pop the clips and pull out the trays to swap cartridges.
Undergravel filters are an excellent supplemental system to keep your aquarium water crystal clear. They are especially helpful in saltwater aquariums. But they’re not designed for tanks that contain plants or sand. Lee’s filters come in a variety of sizes to fit almost any aquarium. And you can connect them to a power filter for faster circulation.
#15 Eshopps WD-75CS Wet Dry Filter – 10 to 75 gallons
The Eshopps Wet-Dry Filter does not come with a pump but is otherwise a complete system with sump. It comes with bio balls, and overflow box, plenty of tubing, and other essential parts. You can use it in both saltwater and freshwater tanks. And Eshopps sells other sizes as well.
#16 KollerCraft TOM RP90 Rapids Pro Filter with UV Sterilizer for Saltwater and Freshwater Aquariums
KollerCraft’s TOM Rapids Pro Filter uses 18-watt ultraviolet light to sterilize the water in an aquarium. The UV light removes green algae and unwanted microorganisms. It’s an excellent choice if you need to control infections, whether among fish, invertebrates, or even coral.
The flow rate of up to 490 gallons per hour means that the TOM RP90 filter can handle aquariums up to 90 gallons. And it’s effective in saltwater or freshwater.
Replacement filters and cartridges for aquarium filtration systems
When you purchase a fish tank filter, you’re also committing to buying replacement cartridges in the future. That’s why it’s important to consider the ongoing cost of maintaining your filter. And it’s also smart to buy from an established manufacturer so that you’re always able to replace necessary parts.
Following is a sample overview of filters for some of the systems we featured in our buyer’s guide today. This way you can quickly figure how much your investment will cost over the long run.
#1 Aqueon Replacement Filter Cartridges
Aqueon’s QuietFlow filters use these disposable activated carbon packs. They need to be replaced every four to six weeks. And Aqueon recommends not washing the Bioholster to avoid killing beneficial bacteria.
#2 Tetra Whisper EX Carbon Filter Cartridges
Tetra’s Whisper EX carbon cartridges are custom-cut to fit in their filter. Just watch the Timestrip to see when it’s time to replace them. And be sure to order the right size insert for your tank.
#3 Marineland Rite-Size Penguin Power Filter Cartridges
Marineland’s cartridges come in a selection of standard sizes. You can buy just one, a few, or a dozen at once.
#4 Marineland Bio Wheel Assembly Filter
The Bio Wheel from Marineland will last quite a while before it needs replacing. Some owners change it every six months; some wait a year.
#5 Aquaclear Biomax
The AquaClear BioMax filter is a host for helpful bacteria. While you need to replace activated carbon every month, the BioMax filter lasts for three months.
#6 AquaClear Zeo-Carb
The Zeo-Carb insert from AquaClear is effective at purifying water in aquariums with lots of fish. It’s also better at controlling water odor than regular activated carbon.
#7 AquaClear 50 Filter Insert Foam
Foam is a mechanical filter that captures dirt before it clogs your biological and chemical filters. While you can rinse the foam every couple of weeks, you’ll want to replace it every two months. But don’t replace all the different filters at the same time because you’ll destroy or remove all the helpful bacteria.
#8 Aquaclear Activated Carbon Insert
Plan on replacing the activated carbon insert every month, or month and a half. And if you use carbon from a reputable manufacturer like AquaClear, you’re less likely to pollute the tank water with phosphates.
#9 Fluval Underwater Filter Poly/Carbon
Fluval’s unique poly/carbon insert for their Underwater Filter combines mechanical and chemical filtration. It’s a custom product that costs a little more than other brands’ activated carbon inserts.
#10 Fluval Biomax Filter Media
Just pour the Biomax filter media into the drawer of the canister filter, and you’re done. These small ceramic rings are an ideal host for colonies of beneficial bacteria.
#11 Fluval Clearmax Phosphate Remover
Phosphate isn’t healthy for your fish either, although it’s a less common threat than ammonia. But if you have sensitive fish or invertebrates, including this phosphate remover in your Fluval filter will protect them.
#12 Fluval Fine Filter Water Polishing Pad
Some fish make more mess than others, but the Fluval Fine Polishing Pad keeps the tank water crystal clear. The polyester pads trap microscopic particles that cause cloudiness. Put them in as the last step in your filtration process.
Aquarium maintenance and cleaning tools
If you have a larger aquarium, it’s easier to clean it on the spot without moving a heavy tank around. Try these tools to test the water and perform regular cleaning.
#1 API POND 5 IN 1 POND TEST STRIPS Pond Water Test Strips 25-Count
Keep an eye on nitrate, nitrite, and carbonates in the fishes’ water. This knowledge will help you decide when to change filter inserts and make water changes, too.
#2 Python No Spill Clean and Fill Aquarium Maintenance System
Although it looks very simple, this tool allows you to suction up debris from the gravel. It’s also very helpful for removing water during partial water changes. And it attaches to a faucet to serve as a hose, too.
Buyer’s Guide to the Best Fish Tank Filters
Aquarium filtration systems keep your fish healthy by removing poisons like ammonia from their water. And there are several different types of fish tank filters to choose from, depending on what you need.
The most common systems offer three levels of filtration: mechanical, chemical, and biological.
- A mechanical filter removes solid material from the water. This might be leftover food or fish excrement.
- A chemical filter usually consists of activated carbon. It neutralizes toxins like chlorine and gets rid of odors.
- A biological filter encourages the growth of beneficial bacteria. The bacteria consume ammonia from fish waste.
If you install a system that circulates enough volume to keep your tank’s water clean, you only need to perform periodic maintenance. That maintenance might be rinsing out the mechanical filter and inserting a new chemical filter monthly. And you’ll also need to change the water every once in a while, too.
Types of fish tank filter systems
Here are the most common types of fish tank filters, beginning with ones for small aquariums.
Air-driven sponge filters
When you have a betta by itself in a small bowl, or you need to isolate a sick fish, or else you plan to raise fry, you might prefer a basic, cheap air-driven sponge filter. It oxygenates the water and captures debris without providing too much water movement. And the sponge that captures waste allows beneficial bacteria to grow and remove toxins like ammonia, too.
Internal power filters
Small tanks that hold 20 gallons or less are the perfect environment for an internal power filter. You can submerge it under the water near the bottom of the aquarium. Then, it stays in place against the tank wall thanks to suction cups. Generally, internal filters are inexpensive, with cheap replacement carbon cartridges, too. And they tend to be quieter than HOB filters.
Some internal filters also add oxygenation with air bubbles. Plus, they keep feces and old food from settling on the bottom but don’t require a lot of maintenance. Depending on your tank’s population, you’ll only need to rinse mechanical filters like sponges and replace activated carbon cartridges each month. The only downside is that you’ll need to remove the entire filter from the tank to clean it.
HOB filters, also known as hang-on-back filters or power filters
HOB filters are one of the most common kinds you’ll see on a home aquarium. They pull in water from the tank, pass it through a multi-stage filtration system, then send clean water back into the aquarium. And they are very easy to maintain since you can change filters pulling the system out of the tank. The only downside is that HOB filters might be noisier than internal filters.
When you don’t use sand or grow plants in your aquarium, you can lighten the load on your primary filter with an undergravel system. It pulls water down through the gravel at the bottom of the tank into a zone where bacteria can process waste. But this type of filter works best when there aren’t many fish living in the tank. And it has the potential to increase hydrogen sulfide in the water, which is toxic.
When you have a large aquarium with many fish, shop for a canister filter. They are best for freshwater or saltwater tanks over 40 gallons. And they offer effective mechanical, biological, and chemical filtration by pressurizing the water to move it through each layer.
Wet/dry systems focus on biological filters. They are commonly found in saltwater aquariums. And they encourage beneficial bacteria to thrive by providing exposure to both air and water. Most wet/dry filters make use of both a sump and a water pump. And they are not as simple to set up and maintain as a HOB filter is.
Which filter is most important?
If you get stuck deciding which type of filter is best, look at the type of filtration is most important to your fish. For example, if you have koi that make a lot of waste and eat a lot of food, but don’t need crystal clear water, make sure that the mechanical filter is efficient. Also, choose a system with a good biological filter to keep ammonia levels under control. Try the AquaClear Power Filter.
But if you have sensitive fish that thrive in crystalline water, put emphasis on a system with a strong chemical filter. And consider adding a mechanical filter with a polishing function like the Marineland Magnum Polishing Internal Canister Filter.
Finally, if you have a problem with algae growing in your tank, try a filter with a UV sterilizer like the KollerCraft TOM Rapids.
Basics of setting up an aquarium
While you might be purchasing a filter for a tank you already have, you might also be pondering a new aquarium. If so, here are some tips to get started successfully.
Choose the fish first
Once you know what kind of inhabitants will be living in your aquarium, you can plan for their needs. Some fish will grow if they are placed in a large tank, while others will not. Some need more light than others. And some will help keep the aquarium clean by eating waste.
Next, choose the tank
Once you understand what your fish need, take into account where you’ll place their tank and what you’ll need to do to maintain it. Keep in mind that even a small tank with 20 gallons may weigh over 200 pounds when it’s full of water, gravel, and equipment.
Now choose the filtration system and other equipment
When you select a fish tank filter, it’s smart to get the best you can afford. A three-level filter that offers mechanical, chemical, and biological cleaning is better, but mechanical and biological will be enough for many situations.
Consider how much work you’re willing to do to maintain your new aquarium. How difficult is it to remove the mechanical filter for cleaning? How easy is it to pop in a new cartridge? Can you support the ongoing cost of replacement filters? And will you have to remove the whole filter from the water or simply open a compartment?
Finally, take into account whether you’ll also need a net to move the fish, a thermometer, a light, an air bubbler, a heater, water conditioner, gravel, and decorations.
The benefits of activated carbon
Many fish tank filters make use of activated carbon to cleanse the water. The carbon might come in a refillable cartridge or a disposable bag. It’s essential to change the carbon as recommended because once it’s full, it will begin to release toxins back into the water.
Activated carbon removes chlorine, copper, proteins, medication, and sometimes ammonia (if combined with zeolite) from the water. It also creates a place for helpful bacteria to live and eat pollutants from the surface of the carbon.
Why bacteria help protect your fish?
Fish poop and make urine, and their waste would eventually poison them if it were not filtered out of their water. The excrement creates ammonia or NH3. But there are two kinds of beneficial bacteria that break down the ammonia into less harmful substances.
These bacteria, Nitrosomonas and Nitrobacter, convert ammonia into nitrites, then into nitrates. But unless you install a biological filter that already has bacteria ready to use, you’ll need to let the colonies mature to protect your fish. One cheap way to start a colony is to mix in some dirty water from a healthy aquarium.
Then when you change the water, be sure to save some of the dirty water, or only replace one-third of the tank at a time. Finally, don’t replace all the filter cartridges or sponges at once because you could remove too much of the bacteria at once.
Choosing the best aquarium filter is essential to keeping your fish and aquatic life happy and healthy. The choice is easier when you know what your fish need, how big your aquarium is, and how much maintenance you’re willing and able to perform. We hope our guide helped you select the perfect fish tank filter today.