Every betta tank needs a filter. It keeps the water clean and clear and reduces harmful substances such as heavy metals and ammonia.
But bettas have specific requirements that you have to know about when choosing a filter. They don’t like fast-moving water; a powerful filter could even suck your betta into it.
Quick Summary: Best Betta Filters
Our Top PickAquaneat Corner Sponge Filter
|AquaClear, Hang-on-Back (HOB) Power Filter||
|Hygger Aquarium Double Sponge Filter||
Let’s look together at some of the best betta filters on the market that will keep your tank clean and your betta happy and healthy.
Aquaneat Corner Sponge Filter
Features: 4ft Airline tubing, 4 Suction cups, 1 Control valve, 1 Tee, 1 Non-return check valve
If you want a small, quiet, yet effective filter to tuck away in the corner of your tank, this could be the one for you. It’s suitable for tanks between 5-20 gallons.
It’s also a very easy filter to set up. Simply install an airline from your air pump and turn it on, and it’s working!
With a low output, 2.5-watt air pump, this filter will run gently enough for your betta to swim well, with no risk of getting sucked into the filter, as can be the case with larger power filters.
The package also contains 4ft of airline tubing, which is a nice extra since you’d normally have to buy air tubes separately.
Lastly, this sponge filter comes at a very affordable price. Even when you include the small cost of the additional air pump, it’s still the cheapest filter on our list.
Things we like:
- Neat, compact design to slot into the corner of your tank.
- Low power usage, quiet, gentle flow.
- Customizable filter media chambers, allow for different types of filtration.
- Extremely affordable.
Things we don’t:
- The hose hookups need to be removed to clean the top of the filter.
Hygger Aquarium Double Sponge Filter
Features: 2 Spare Sponges, 1 Bag of Bio Ceramic Media Balls, Quiet Submersible Foam Filter for 10-40 gallon aquariums.
This is an excellent dual sponge filter from aquarium specialists Hygger.
Sponge filters are a great choice for betta tanks because of their gentle flow and effective biological and mechanical filtration.
Even better about this model is that there are not one but two sponges plus a ceramic filtration for enhanced biological filtration.
The sponges are made from high-tech, low-micron foam with 60 PPI (pores per inch) – allowing these sponges to filter out even very fine particles. It also provides lots of surface area for beneficial bacteria to colonize.
One of the advantages of the double sponge design is that you can replace one sponge at a time.
This means you will always have at least one sponge fully colonized with good bacteria, providing safe, effective biological filtration.
The chamber containing the ceramic balls can also be customized to accommodate carbon or other types of filter media if you wish.
Things we like:
- Can produce a gentle flow with the right air pump.
- Double sponge system is very efficient and allows the change of one sponge at a time.
- Ceramic balls give extra biological filtration.
- Customizable filtration media.
- Small, quiet, and unobtrusive.
Things we don’t:
- You need to purchase an additional air pump.
- Suction cups often come off.
Aqueon QuietFlow LED PRO Internal Power Filter
Features: Four-stage filtration, Adjustable Flow Rate, LED Light Indicator
The Aqueon QuietFlow filter series are well known in the trade as good, reliable power filter.
They come in various sizes, with models suitable for 3-gallon, 10-gallon, 20-gallon, and 50-gallon tanks.
These internal filters flow quite fast, and each model’s recommended tank size is more suitable for regular community fish.
Since bettas need a slower flow, it may be better to go for a slightly larger tank than specified so that the current doesn’t overwhelm your betta.
These internal filters feature four stages of filtration
- Stage 1: Dense floss removes particles and debris.
- Stage 2: Activated carbon removes toxins, odors, and discoloration.
- Stage 3: Bio-Holster removes toxic ammonia and nitrites.
- Stage 4: A diffuser grid removes additional toxins while adding oxygen to the water. It also reduces splashing to make the water’s return quieter.
Since this filter incorporates carbon filtration, fewer nutrients, such as iron and calcium, will be available to your live plants if you keep them.
The LED lights indicate when it’s time to change the filter’s floss cartridges, although they may be rather over-efficient!
Things we like:
- Four-stage filtration keeps water exceptionally clean.
- A well-known filter series that has been tried and trusted for many years.
Things we don’t:
- Flow may be too strong for bettas, especially those with long fins.
- Carbon filtration may remove too many plant nutrients.
- LED light system encourages you to change cartridges often, which becomes expensive.
AquaClear, Hang-on-Back (HOB) Power Filter
Features: 3-Stage filtration, low 5-watt power, Adjustable Flow Rate, Customizable Filter Media.
These AquaClear Hang-On-Back Power Filters are another stalwart in the fishkeeping world. They come in various sizes for tanks of 5-20 gallons, 10-30 gallons, 20-50 gallons, and more.
The three-stage filtration of foam, carbon and bio-ceramic rings offers an exceptionally long contact time between the water and the various mediums, producing crystal clear water.
The motor is cooled and lubricated by water, so it must remain continuously submerged to prevent the motor from burning out.
It’s extremely important, therefore, to keep an eye on your tank’s water levels – HOBs tend to increase the evaporation rate from your tank!
Although HOB filters are often too powerful for bettas, this model features a control nob to adjust the flow rate between 33-100 gallons per hour.
Even the minimum flow, however, may still be quite strong for a betta with long fins in a small tank.
Things we like:
- An excellent filter series from a trusted brand.
- 3-stage filtration and long contact time for super clear, clean water.
- Customizable filter media to suit your preferences.
- Adjustable flow rate.
Things we don’t:
- Even the smallest model with the minimum flow may be unsuitable for a nano betta tank.
- The impeller needs lubricating with vaseline or similar products to remain quiet.
AQQA Aquarium Biochemical Sponge Box Filter
Features: Quiet operation, Compact design, 1 Spare Sponge, 1 Bag of Bio Ceramic Media Balls
This neat little sponge box filter has ceramic media balls and a large sponge, offering good mechanical and biological filtration capabilities.
It has a nice in-built airstone so that the air input is dispersed into masses of tiny bubbles, helping to oxygenate your tank’s water.
This filter is versatile because it’s small, and you can position it anywhere in the tank. It doesn’t need to be stuck to the sides.
The small version of this filter is great for nano tanks, but for tanks above 15 gallons, we’d recommend you go for at least the medium size, which is substantially bigger.
Things we like:
- Compact design, quiet and discreet.
- Creates smaller bubbles than other sponge filters for more gas exchange.
- Small model good for nano tanks.
Things we don’t:
- Some customers have complained that plastic components become jammed.
- The medium size version is rather large and clumsy.
Tetra Whisper Easy-to-Use Air Pump for Aquariums
This is not a filter but an air pump that needs to be purchased to power any of the above sponge filters.
Tetra-Whisper Air pumps have been very popular for years due to their reliability and quiet design.
They’re also very low-cost.
They come in different sizes for tanks up to 10 gallons, 10-20 gallon tanks, 40-gallons, and more.
The smallest 2.5-watt model is ideal for a small betta tank.
Things we like:
- A tried and trusted series of air pumps you can rely on.
- Innovative, quiet design.
- Great value.
Things we don’t:
- Air hose must be purchased separately unless one comes with your sponge filter!
Understanding Aquarium Filters for Betta Fish
Aquarium filters may sound complicated at first. Terms like 3-stage filtration, nitrifying bacteria, and filter baffling may initially make you feel slightly out of your depth.
But the basic principles behind aquarium filtration are remarkably simple. Let’s get to understand them.
The 3-Stages of Filtration
Stage 1 – Mechanical Filtration
Mechanical filtration simply means physically filtering out the little pieces of dirt floating around in your fish tank’s water by a porous medium.
Mechanical filtration is primarily performed with some kind of pad made from sponge, foam, or floss.
As the small particles get sucked into the filter, they get lodged in this porous material so the water can flow back out without them.
With time these particles build up, and it’s amazing after one month to see just how much your sponge has pulled out of the water!
Stage 2 – Biological Filtration
The mechanical media (sponge, foam, or filter floss) in your filter also serves as a home to millions of beneficial bacteria that help to keep your water safe and clean.
Some filters even contain extra ‘biological media’ like ceramic balls to host even larger numbers of these friendly bacteria.
These bacteria are called nitrifying bacteria because they are a fundamental part of the nitrogen cycle, which we’ll learn about in the next section.
Let’s just say that biological filtration harnesses useful bacteria to convert toxic substances into relatively harmless ones.
Stage 3 – Chemical Filtration (optional)
Chemical filtration normally refers to some form of activated carbon within the filter.
This is basically charcoal, not so different from the stuff you put in your barbeque or use in your art classes at school.
Charcoal is an amazing chemical filter because its structure is like a massive sponge.
Looking at it under a powerful microscope, you’d see a vast matrix of tiny pores. These are brilliant for soaking up microscopic particles that make your water look cloudy and smell nasty.
Carbon is also effective at absorbing harmful toxins in the aquarium, and also certain soluble medicines were added to the tank to treat the fish.
On the downside, carbon can also absorb useful nutrients for aquatic plants, such as iron, calcium, nitrogenous compounds even carbon dioxide.
Hobbyists with lots of plants or aquascapes sometimes prefer to avoid carbon as a permanent component of their filter system.
3 Types of Filters That Are Suitable For a Betta Tank
A very popular type of filter for aquariums is the HOB or Hang-On-Back style filter. As the name implies, the main unit hangs on the back of the tank.
One advantage of HOBs, therefore, is that they sit outside of the water, offering more living space for your fish and plants.
An intake tube runs from the unit into the tank to suck water into the filter. The water then flows through various chambers containing different filter media before being returned to the aquarium through an outlet that usually sits just above the water’s surface.
This water flow, splashing back down into the tank, is good for creating bubbles and oxygenating the water. Yet, it can also be noisy – sounding like anything between a quiet trickle and a constant waterfall.
The increased contact of water with air also accelerates evaporation, so you’ll need to top up your tank more often.
HOBs are often not considered the best filters for bettas because, while very efficient, they often have a strong flow.
Bettas, especially those with long fins, hate currents and will become quite stressed in a small aquarium battling against a strong flow.
Luckily, some HOBs comes with an adjustable flow rate. If you choose a HOB, check that it’s a model that can be adjusted to make it suitable for betta tanks.
Internal Power Filters
Internal power filters work similarly to HOBs, but they’re immersed in the water instead of sitting behind the aquarium.
This system means that the output can also be submerged, reducing splashing and water evaporation.
However, some aquarists will still opt to position the outflow above the water to increase their fish’s gas exchange and oxygen levels.
A good internal power filter can run fairly quietly when completely submerged, but it depends greatly on the manufacturer’s quality.
See the FAQs below to find out what you can do about a noisy filter!
Sponge filters are a simple and economical way of filtering aquarium water. Although they’ve been around for a long time, innovations in foam technology have made the modern versions much more efficient than the older ones.
Unlike power filters, sponge filters are usually powered exclusively by an air pump. Instead of a flow created by an electric impeller, bubbles from the air pump pull water through the filter’s sponges.
In addition to one or more sponges, some sponge filter models also contain chambers for additional media, such as bio-ceramics and carbon, to facilitate enhanced biological or chemical filtration.
While sponge filters may be less powerful per unit than power filters, this can be a benefit in a betta tank. You simply choose an air pump with the appropriate output strength to control the filter’s flow.
Although air pumps need to be purchased separately, they’re normally cheap and reliable. A 2.5-watt air pump is powerful enough to manage a 10-gallon betta tank.
Types of Filters Less Suitable For Betta Tanks
Undergravel filters consist of a plate that lies under the gravel at the bottom of the fish tank. It sucks water down, through the gravel, and into the holes in the plate, before recirculating it back up to the tank again.
Undergravel used to be much more popular than they are today. Although they utilize the gravel as a huge biological filter, you’ll have to clean your gravel all the time to collect up the waste accumulated there. In other words, the system is fairly high-maintenance.
While some still choose under-gravel filters for large tanks, they’re not such a great option for the smaller tanks normally associated with bettas.
Cannister filters are some of the most powerful filters available for larger aquariums.
They’re normally much larger than the other filters and sit underneath the aquarium.
Their large size allows them to accommodate a lot more filter media so that the water gets the most thorough clean possible. This makes them great for freshwater and saltwater setups that exceed 50 gallons in size.
They are, however, more expensive, more difficult to clean, and better suited to advanced fishkeepers with large tanks.
Which Type of Filter is Best for a Betta Tank?
As we’ve said, bettas don’t like strong currents. Think about their natural habitat. In the slow-moving or still-water rice paddies and pools of South East Asia, there is hardly any current for bettas to deal with.
Moreover, the bettas kept in captivity today have been bred to have much longer fins than their wild ancestors, making it even harder for them to swim against currents.
It’s sad, but it’s not unknown for a betta owner to come home and find their dead betta pinned against the intake of a too-strong filter for them.
Even if they avoid being sucked into the filter, a moderately strong current coming from the tank’s outlet could cause your betta a lot of stress and the unnecessary struggle over time, damaging his health and limiting his lifespan.
Therefore, the main consideration for buying a betta filter has a slow, gentle current.
Sponge filters are ideal for this when attached to a low-wattage air pump. Some hobbyists even use multiple sponge filters for larger tanks instead of risking a power filter.
If you do choose a power filter, you must choose a model where you can adjust the flow. Even using the minimum setting, it’s still vital to observe your betta see how he’s dealing with the current.
Please read our FAQs at the bottom to understand how you can reduce or deflect your filter’s flow.
Understanding The Nitrogen Cycle
Like any animal, fish produce waste that contains lots of nitrogen, and the particular nitrogenous compound that fish excrete is called ammonia.
Ironically, ammonia is highly toxic to fish, even at relatively low levels, so it’s essential that it’s quickly converted into something less harmful.
Luckily, a group of bacteria can do this job for us. Nitrifying bacteria live in the tank’s substrate and filter media, transforming harmful ammonia into nitrites and then nitrates.
While nitrates can still be toxic to fish in large quantities, they’re much less harmful than ammonia. They can be controlled by regular water changes and/or by live aquarium plants that absorb them to grow.
Looking After Beneficial Bacteria
The millions of nitrifying bacteria in your filter work night and day to ensure that your fish don’t die from ammonia poisoning. It’s essential, therefore, that you keep their populations in good shape!
Never introduce any fish into an aquarium that hasn’t been cycled. Every tank must be run through a filter for 10 days to several weeks before sufficient bacteria colonies have built up on the filter medium to keep the water chemistry safe and stable.
It’s essential to keep a portion of the population alive and healthy every time we clean the filter too…
Washable vs. Replaceable Filter Media
Before you buy a filter, it’s a good idea you know how to clean it.
Whereas some filters come with a sponge that you can take out and wash, others come in plastic cartridges that need to be bought each time from the manufacturers.
It comes down to personal preference, whether you’re up for getting your hands dirty and washing your sponge by hand or prefer a neat cartridge you can throw away and replace each month.
Of course, washable sponges are more ecological since they create much less waste. They’re also cheaper as you don’t have to pay for replacement cartridges all the time.
This is a hidden cost for filters that employ a replaceable cartridge system – they can become quite expensive over time.
Cleaning An Aquarium Filter
If you opt for the washable style of filter, you’ll need to clean it every 2-4 weeks, depending on its size, the type of filter, and how much waste (or bio-load) is produced in your betta fish tank.
To avoid killing your fish, you must clean your filter sponge properly! Never use tap water to clean your filter media, as it can kill the beneficial, sending your tank’s water chemistry into chaos.
As we’ve said, filter media contain millions of essential bacteria that convert deadly ammonia into safer compounds. If you kill these beneficial bacteria, your tank will fail to cycle properly, and your fish could die.
With clean hands, carefully remove a bucketful of water from the aquarium, then remove the filter sponge. Be careful not to squeeze dirt from the sponge back into the tank.
Gently clean off the worst fish waste on the outer layers of the sponge, and give it a gentle couple of squeezes in your bucket of tank water. Return the cleaned sponge back into the filter.
Do Betta Fish Really Need a Filter?
The short answer is Yes! They do.
This has been a subject of some debate for a long time among hobbyists. While it’s true that people have been keeping bettas for a thousand years, long before electric filters were invented, they must have had to take far more rigorous care of their betta’s water too.
If you really want to change part of your betta’s water every couple of days, go ahead and try living without a filter.
But if you don’t do the manual work necessary to replace a filter, you can’t expect your betta to live for long.
Bettas that live in cramped conditions without proper water maintenance often die within their first year.
Do I Need a Carbon Filter for Betta Fish?
Activated carbon is an extremely effective filter medium for removing tiny particles from the water and keeping the water crystal clear. Yet it also removes some important plant nutrients such as iron, calcium, and even carbon dioxide.
If you have a heavily planted aquarium or aquascape, we’d suggest not using a carbon filter all the time.
In special circumstances, such as if you need to remove medication from the tank’s water post-treatment, or need to make the water less cloudy, then you could employ carbon filtration for a few days until conditions clear up.
Will My Betta’s Tankmates Enjoy the Same Filtration As My Betta?
Not necessarily. While shrimps and snails will enjoy the same gentle current that your betta does, other fish sometimes prefer a stronger current.
Plecos definitely fall into this category since most species of the Plecostamus family are from fast-flowing streams of South America.
One way to make both species happy is to choose a power filter with an adjustable output nozzle, so you can point the filter’s outflow down toward the gravel where your pleco lives and away from the surface water where your betta likes to hang out.
How Can I Reduce Flow From My Betta’s Filter?
If your filter outlet is too strong for your betta, there are various measures you can take to reduce the flow.
Firstly, find out if you can adjust the flow of your filter. Check the instruction manual – sometimes, the flow adjustment mechanism can be very discreet.
If the flow is still too strong, you could try directing it away from the main swimming area of your betta.
If your filter outlet doesn’t have an adjustable nozzle, you may be able to buy or make a ‘flow deflector’ to direct the flow in a different direction.
Similarly, you can solve the problem by creating a ‘filter baffle’ – any device that reduces the filter’s output flow. There are many options – plastic bottles, filter sponges, and shower caddies.
Read our guide here to learn more about reducing the current in a betta tank.
What Can I Do To Reduce the Noise of My Aquarium Filter?
If your filter is rattling, try turning it upside-down in the water to remove any bubbles that may have gotten stuck in the system.
Lubricating the impeller with petroleum-based jelly and securing or removing loose pieces of plastic housing may also prove an effective remedy.
What’s a Good Filter for Breeding Bettas?
If you’re interested in raising baby bettas, you’ll need to choose an extremely gentle filtration system. This helps to avoid sucking up the fry or pushing them around with a strong flow.
Once again, sponge filters are excellent for this and should still be powerful enough to deal with their waste.
Do I Need Bubbles to Oxygenate My Water in a Betta Tank?
Bettas are labyrinth fish, meaning they can inhale a portion of their oxygen from the water’s surface.
So while it’s not essential, some betta owners still feel their pet fish is happier when the water is well-oxygenated.
Since sponge filters create a fizz of tiny bubbles as air passes through them, these filters are great at increasing oxygen and carbon dioxide levels in your tank for your fish and plants.
My Top Pick
My favorite types of filters for betta tanks are sponge filters with additional biological media. There are many good models, but my top pick is the Aquaneat Corner Sponge Filter.
I like how you can tuck this filter away in the corner of the tank so that it remains discreet while continuing to clean the water effectively.
It also puts the power in the hands of the fishkeeper – allowing you to customize your own filter medium and an air pump to control its power and efficacy.
This filter comes with a four-foot airline hose, so with the addition of a Tetra Whisper Air Pump, it’s one of the least expensive and easy-to-setup filters you could hope to find.
Click here to jump ahead and check the latest price for the Aquaneat Corner Sponge Filter.