Selecting the best filters for 5-gallon tanks can be confusing as there are many things that you need to keep in mind, from flow rate to durability. While any aquarium needs good filtration to thrive, It’s extra important in nano aquariums as there is less room for error.
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Using the wrong type of filter can have disastrous consequences, which is something I discovered when I was a new fishkeeper over a decade ago (long story short, I ended up with an ammonia spike that wiped out my entire tank).
That’s why I’ve compiled a list of some of the best 5-gallon aquarium filters to make sure you don’t run into the same mistake that I did. I’ve also covered some important information about filters in general, including what to look for in a filter, further down in this article.
Let’s get started!
- Selecting the right filter for a 5-gallon tank is crucial, and it’s especially important for nano aquariums due to limited space.
- The Aqueon QuietFlow E Internal Power Filter is the top pick for its ease of installation, self-priming auto pump, and quiet operation, while the Penn-Plax Smallworld Water Filter offers excellent value with chemical, mechanical, and biological filtration, and the AquaClear 20 Power Filter is the editor’s choice, delivering powerful filtration at 100 GPH with included filter media.
- Factors to consider when choosing a filter include cost, filter type, flow rate, build quality, included features, ease of maintenance, and warranty.
On to the Reviews…
Boasting a compact design and powerful auto-start pump, the Aqueon QuietFlow E Internal Power Filter is a good choice for a 5-gallon tank as it efficiently filters water and is simple to set up.
The Aqueon QuietFlow E Internal Power Filter is my top pick for a 5-gallon fish aquarium due to its simple installation, self-priming auto pump, and quiet operation.
It easily and effectively filters water in small fish tanks thanks to its powerful and self-priming pump. The latter will automatically restart if power to the device is cut off or reactivated, which is useful if you experience a power outage.
Although listed for only being suitable for aquariums up to 3 gallons, it is actually ideal for setups up to 5 gallons as it has a flow rate of 25 GPH (Gallons Per Hour).
As a rule, your filter should be able to turn over 4 times the volume of your tank, so a filter with a GPH of 25 is plenty for a 5-gallon aquarium!
The Aqueon QuietFlow E Internal Filter is also easy to install as it comes with suction cups, allowing you to affix it to your tank with ease.
Better yet, this 5 gallon aquarium filter kit comes with a free activated carbon cartridge to remove odors and give your tank water an extra level of polish. With this inclusion, the device offers chemical, mechanical, and biological filtration!
However, this small fish tank filter can be a little inconsistent in quality depending on the unit. I’ve used this 5 gallon aquarium filter for a few of my betta fish setups, and I’ve noticed that sometimes the filter lasts for years, and other times it stops working after a few months.
Despite this flaw, I still think it’s a great option for a small aquarium or nano aquarium, especially those that house a single fish like a betta.
- Filter Type: Internal
- Flow Rate: 25 GPH
- Dimensions: 2.75” x 2.75” x 6.81”
- Quiet during use
- Simple to install and set up
- Comes with a free activated carbon filter cartridge
- Auto-start pump that reactives if power is interrupted/turned back on
- Quality can be a bit inconsistent
The Penn-Plax Smallworld Water Filter is the best filter for aquarists on a budget as it offers biological, mechanical, and chemical filtration at an affordable price. It comes with suction cups, a mounting bracket, filter media cartridge, an adjustable flow rate, and a connector.
If you need a good-quality but budget-friendly for a small aquarium or nano aquarium, the Penn-Plax Smallworld Water Filter is well worth considering as it’s designed specifically for 5-gallon fish tanks.
I really like the compact and vibrant design of this 5 gallon aquarium filter – it’s a bright shade of green to really make your aquarium pop!
It provides chemical, mechanical, and biological filtration as it comes with a filtration media cartridge. This cartridge contains zeolite and carbon, which helps absorb ammonia, nitrite, nitrate, and phosphates. It also doubles up as a bio-sponge for beneficial bacteria to grow on.
The filter includes suction cups and a mounting bracket to allow you to install with ease, alongside a connector that you can attach to standard air tubing. The filter also has an adjustable valve so you can change the flow control.
However, the adjustable flow control valve on this filter for small aquariums can be quite difficult to turn (the knob is quite stiff). It can also be a bit noisy, though I don’t think this is a huge problem unless you’d prefer a quieter filter.
- Filter Type: Internal
- Dimensions: 6” x 2” x 6”
- Flow Rate: Not Specified
- Adjustable flow rate
- Vibrant and compact design
- Offers chemical, biological, and mechanical filtration
- Comes with a filter cartridge that contains zeolite and activated carbon
- Can be a little noisy
- Flow rate controls can be hard to use
The AquaClear 20 Power Filter is one of the best filters for nano aquariums as it’s strong, effective, and provides you with all the filter media you need to keep your fish tank clean.
Another one of the best filters for small aquariums is the AquaClear 20 Power Filter. This is one of my personal favorite HOB filters to use for my nano aquariums due to its excellent performance.
It has a flow rate of 100 GPH and offers chemical filtration, biological filtration, and mechanical filtration for superior water quality. It also comes with own media which includes biological media, chemical media, and mechanical filter media, which is great as you won’t need to buy your own filtration media!
The filter casing is strong and durable, allowing it to stand up to the test of time (and mischievous small fish that like to nibble on your tank equipment!). You can adjust the flow rate of the filter to increase or decrease the current, which is ideal if you want either fast or slow-moving waters.
A feature I really like about the adjustable flow rate of this small filter is that even at a slower flow, up to 50% of the water inside the chamber is turned over multiple times to maintain the device’s filtering efficiency.
The only downsides of this power filter for nano tanks are its noisiness and unreliability, at least long-term. However, you can muffle the sound of the filter a little by smearing some vaseline on the impeller to help lubricate it.
Additionally, this external power filter comes with a lifetime warranty, so if it breaks or develops an issue, you’ll be able to get a replacement!
- Filter Type: HOB
- Flow Rate: 100 GPH
- Dimensions: 4.5” x 7” x 6.5”
- Strong casing
- Includes filter media
- Flow rate can be adjusted
- Provides chemical filtration, mechanical filtration, and biological filtration
- A little noisy
- Can be unreliable long-term
If you need a quiet, good-quality internal filter that won’t break the bank, the Tetra 4i Internal Power Filter is a solid choice.
Next up is the Tetra 4i Internal Filters, which is an affordable but good-quality filter system for small fish tanks. It has an internal 27 GPH pump, so it’s plenty powerful enough for aquariums that are 5 gallons in volume.
This Tetra filter boasts a space-saving design and comes with an adjustable clip and suction cup so you can easily attach it to your tank water. It also comes with a filter media cartridge that contains activated carbon to keep your tank sparkling clean.
This means it offers chemical filtration, mechanical filtration, and biological filtration. And best of all, it’s relatively quiet when in use!
Unfortunately, this internal filter can be a little hard to install as the included clip can be difficult to use on some setups.
- Filter Type: Internal
- Flow Rate: 27 GPH
- Dimensions: 3” x 3” x 7.38”
- Space-saving design
- Comes with suction cups, mounting clips, and carbon cartridge
- Mounting clips may be unsuitable for some tanks
The AZOO Mignon Filter 60 is one of the smallest HOB filters available due to its compact but sleek design. It’s a decent option for shrimp or betta tanks and includes biological sponge filter pads.
Another decent filter for a small fish tank is the AZOO Mignon Filter 60, which sports a small, compact design – it’s actually one of the smallest external power filters on the market!
It offers quiet performance and quick maintenance, making it a good choice for aquarists who need a silent filter that is easy to clean. It comes with a pre-filter sponge that is ideal for promoting the growth of beneficial bacteria.
The clear housing of this fish tank filter allows you to clearly view inside the chamber, which is a feature I really like as it means you’ll be able to see when your filter pads need replacing (i.e., they’ll be dirty!).
While you can adjust the flow rate of the filter to up to 16 GPH, this is a little low for most 5-gallon aquariums. That being said, it’s still a good choice for shrimp or betta tanks.
- Filter Type: HOB
- Flow Rate: 16 GPH
- Dimensions: 3.25” x 3.75” x 6”
- Compact design
- Comes with biological filter media
- Clear housing allows you to view inside the filter chamber
- Flow rate is only 16 GPH
If you need a reliable and powerful filter for your aquarium, the PULACO Ultra Quiet Aquarium Hang on Filter is a good pick. It has a flow rate of up to 66 GPH and comes with sponge filter cartridges.
Last but not least is the PULACO Ultra Quiet Aquarium Hang on Filter, which boasts a powerful motor, an adjustable flow knob, and easy installation.
It has an adjustable flow rate of up to 66 GPH, so it will have no trouble filtrating the water in a small fish tank. The included biological filtration sponge will easily trap debris and other particulates in your aquarium water, as well as provide a space for allowing beneficial bacteria to colonize.
This filter hangs outside of your aquarium. It’s also easy to install as it comes with a mounting bracket so you can attach it to the outside of your small aquarium.
My main gripe with this filter is its noisiness – it can emit a fairly loud buzzing sound during use. The suction may also be a bit too strong for delicate or slow-moving fish like bettas, so this is something to keep in mind if you decide to use this filter.
- Filter Type: HOB
- Flow Rate: 66 GPH
- Dimensions: 4.3” x 4.7” x 3.5”
- Easy to install
- Powerful motor
- Comes with sponge filter cartridges
- Suction may be too strong for fragile fish
Does a 5 Gallon Fish Tank Need a Filter?
Aquariums, especially nano tanks like a 5 gallon tank, need clean and healthy water for fish to survive. While it’s possible to successfully maintain a tank without a filter, it’s always better to use one, particularly if you’re new to fish keeping as it will help you maintain a healthy environment by keeping your tank water clean.
What Size Filter Is Best for a 5 Gallon Aquarium?
A fish tank filter with a flow rate of at least 25 GPH is best for a 5 gallon tank setup. As a general guideline, your filter should be able to turn over your tank water at least 4 times per hour.
You’ll still need to consider the size and bioload of your fish. Large species or those that produce a lot of waste will benefit from a more powerful filter system with a higher flow rate.
How Long Does It Take to Filter a 5 Gallon Fish Tank?
It typically takes 1 hour for a filter to fully filtrate a 5-gallon aquarium.
What Filter Is Best for a 5 Gallon Tank?
The best filter for a 5-gallon setup depends on the size and bioload of your fish, as well as personal preference.
I’d personally recommend either a HOB filter or internal filter as both are powerful while being fairly easy to maintain. They also don’t take up a huge amount of space.
How to Choose the Best 5 Gallon Tank Filter for Your Tank
Choosing the right 5-gallon filter for your aquarium can be a big decision as there are a lot of things you’ll need to think about, including its quality, flow rate, features, and your overall budget.
Ideally, you should use the highest quality filter you can afford so its performance isn’t hindered and it doesn’t break prematurely.
Included accessories such as filter cartridges can also be useful to save you the hassle of purchasing them separately.
What Should You Consider In a 5 Gallon Aquarium Filter?
Before you select a filter for your tank, you’ll need to think about the cost of the filter, its type, flow rate, build, and features. This will help you choose the right one for your needs and setup.
Below are some of the things you should consider in a 5-gallon filter to ensure you select the right one for your setup and needs.
How Much Does It Cost?
First and foremost, you’ll need to consider the price of the filter and your budget. It’s also worth thinking about whether the cost of the filter is an indicator of its quality.
Less powerful devices or those made from inferior materials may be inexpensive, but they could break prematurely, meaning you’ll need to purchase a replacement and therefore spend more money in the long run.
What Type of Filter Is It?
Aquarium filters come in a variety of types, and the right one for your aquarium will depend on your setup, as well as the species of fish you own.
The most popular types of fish tank filters are:
- HOB (Hang-on-Back) Filter
- Internal Filter (Traditional In-Tank Filter)
- Undergravel Filter
- Canister Filter
- Sponge Filter
HOB or internal filters are normally used in nano aquariums as they offer proper filtration without taking up too much space in your setup.
A sponge filter is ideal for delicate or sick fish, whereas an undergravel filter is useful for heavily planted setups. A canister filter is best for larger tanks, but it can also work in small tanks with a lot of fish waste.
What Is the Flow Rate?
The filter you use for your 5-gallon setup will need to have a suitable flow rate, ideally at least 25 GPH. Any lower than this may not be enough to keep your tank clean and healthy.
Does It Include Any Features?
Some filters have useful features like an auto-start pump or indicator light that blinks when you need to change your filter media cartridge.
Although not essential, these types of extras can be convenient and may save you some time. Buying a unit that doesn’t require a separate external pump will save you money.
What Is the Build?
As 5-gallon fish tanks are already quite small, it is best to avoid overly bulky filters that will reduce the amount of swimming space your fish have access to.
Opt for a filtration system with a space-saving, compact build so your fish have as much room as possible.
Is the Maintenance Easy?
Every filter needs regular maintenance to keep it running smoothly and effectively, so you should use a filtration system that makes this process simple and quick.
Canister filters tend to be the hardest to clean, whereas cleaning sponge filters are usually the easiest.
Does It Include a Warranty?
While filters can break prematurely if they are not cared for properly, sometimes it may be due to a fault with the craftsmanship.
That’s where at least a 6-month warranty can come in handy – you’ll be able to either get a replacement or a refund if your filter breaks shortly after you’ve purchased it.
FAQs About Aquarium Filters
What Is the Best Type of Aquarium Filter for a 5 Gallon Tank?
This is mostly down to personal preference, but a HOB filter tends to be a good choice as you can install it on the outside of your aquarium to provide your fish with more swimming space.
However, any filter will do the trick as long as it is powerful enough for the size of your aquarium!
Is a Sponge Filter Enough for a 5 Gallon Tank?
Sponge filters are usually sufficient for 5-gallon aquariums, but it will also depend on the number and type of fish in your setup. Sponge filters are best used for small betta fish tanks, dwarf cherry, fry (baby fish), injured or sick fish, and small or delicate species.
Species that produce a lot of fish waste will need a more heavy-duty unit, so they may benefit from power filters, canister filters, or strong internal filters.
What Flow Rate Do I Need for a 5 Gallon Tank?
You should aim to use a filter with at least a flow rate of 25 GPH.
Do I Need a Filter for My Betta?
Yes, you need a filter for your betta! Like any fish, bettas need clean and healthy water to thrive.
Can You Use a 10 Gallon Filter In a 5 Gallon Tank?
Yes, you can use a 10-gallon filter in a 5-gallon aquarium! However, you may need to lower the flow rate as it could be too strong for some fish species, particularly small fish or those that prefer slow-moving waters like the betta fish.
Can You Over-Filter an Aquarium?
No, you can’t over-filter an aquarium – more filtration is always a plus! But you should know that using a strong filter such as a canister filter can cause strong currents which can have negative effects on fish.
How to Tell If You Need to Change Aquarium Filter 5 Gallon
One of the biggest signs that you may need to replace your aquarium filter is if it has lost suction or is no longer working as well as when you first bought it.
However, filters can lose suction if the impeller is clogged, so it’s always worth dismantling the unit first and giving it a thorough clean (with old tank water so you don’t lose any beneficial bacteria!
Do I Need to Do Water Changes If I Have a Filter?
Yes, you will still need to do water changes even if you have a filter. A filter only filtrates your aquarium water and helps clean it by removing debris like uneaten food from the water column.
It will not keep your water chemistry stable and remove the build up of ammonia, nitrite, or nitrate. Only frequent water changes will do this!
I hope this guide gave you some recommendations on the best filters for 5-gallon fish tanks, as well as gave you some pointers on how to choose the right fish tank filters for nano tanks!
Which filter do you plan to use for your fish tank? Be sure to let me know over on our social media platforms and share this post with other fish fanatics!
If you’re looking for more aquarium-related product reviews, guides on fish keeping, or anything about aquatic life, take a look at our other articles.