Best Small Aquarium Filter

Are you looking to get your first aquarium? Fish are mostly a low maintenance pet which look great in your home. If you have kids, a nano or small aquarium is a fantastic way to show them how underwater environments can thrive. 

Before adding any fish to your tank, you need to let the water stabilize. One step which is vital to doing this is adding a water filter to your aquarium. There are many different models to choose from so we thought we would make it nice and easy for you by listing our favourite products below.


We really do believe that Tetra has come through with this product. The filter easily mounts to the side of your aquarium and doesn’t take up a lot of space. Perfect for your smaller tanks! This design also makes it possible to place your aquarium up against the wall with its slimline layout. 

This is one of the most effective filters on our list and that’s why we chose it for the top pick. It can actually filter up to 125 gallons per hour ensuring that your aquarium’s water is fully oxygenated at a quicker rate than other products. 

Our top pick doesn’t have to be the most expensive option either! This is reasonably priced for the quality of the filter. We really are impressed with how well this filter works!

As we’ve mentioned above, this is our top choice when looking for a filter for a small aquarium. Not only does it have a slimline design but it also is one of the quieter recommended filters. As this filter sits below the water, you can barely hear it working away in the background. It really does whisper!

Instead of filtering through a sponge, this filter uses Whisper Bio-Bag filter cartridges. These have been produced especially for this model and you will get one included in your purchase. What we love about these cartridges is that they are super convenient to change. That means cleaning your tank and filter maintenance will never be easier!

This filter is suitable for aquariums from five to ten gallons. If you’re starting out with a nano tank, this would be a great option for you to try out.


  • Budget-friendly option.
  • Easier filter maintenance.
  • Slimline design.



This filter is perfect for tanks from 1.5 to 10 gallons in size. It pumped out an impressive seventy gallons per hour to keep your tank’s water fresh and clear. This product comes with an internal sponge which promotes the production of beneficial bacteria for your aquarium. 

You are able to set up this filter in two ways. The first option is to have it over the water, only half of the filter is submerged. This setup is perfect for smaller fish like bettas. It works by acting as a spray and evenly pumps filtered water throughout your aquarium. 

This product is also fully submersible and can easily be fitted to your tank horizontally. This means that it is out of sight and not as bulky or intrusive as other models may be. By using this setup, the filter sits towards the bottom of the tank and the multiple nozzles get to work at purifying that water!


  • Two different ways to set up the filter.
  • Fully submersible.
  • Compact design.


  • Does produce a light humming noise.


If you’re just starting out with your aquarium, we think that this is a great product for you. Zoo Med has taken into account how difficult some brands make installing a filter and come up with this device. It is perfect for aquariums of up to ten gallons. It can also be used in both freshwater and saltwater tanks.

There are many additional extras included when you buy this filter. You get the Nano 10 canister filter, the filter sponge, spray bar, carbon chemical filtration media, and the bioceramic filtration media.

We personally love a filter that comes with a spray bar as it is less disruptive to smaller breeds of fish. It provides a more gentle experience for them but still promotes fresh and clean water for them to live in.

The design of this aquarium filter is quite compact which makes it great for smaller tanks as it doesn’t take up too much space. It is also designed to be a quieter model.



  • A more expensive model.


This product is suitable for aquariums up to fifteen gallons. It has a top of the range filtration system that ensures that your water is oxygenated. This means that your water will stay clear for longer periods of time. 

The Fluval Nano Aquarium Filter also comes with an attachable spray bar. Like we’ve previously mentioned, this is a great addition to any filtration device. The way that the spray bar distributes water is much more delicate than other products that may not have one included. The gentle water flow promotes a clean environment for your fish to live in and is even safe for shrimp. 

The Bio-Foam sponge works well to catch any debris which may make its way through the product and ensures that there is efficient water flow in your aquarium. The Bio-Foam sponge is also designed with much smaller holes than other sponges on the market. This makes for fewer times which you will have to unclog the filter!


  • Comes with an attachable spray bar.
  • Ensures water is oxygenated.
  • Bio-Foam sponge has an improved design.


  • Can be difficult to clean.


This power filter easily clips onto the side of your aquarium and is suitable for aquariums from five to twenty gallons. It is super easy to install and comes equipped with all the essential parts you need to oxygenate your water. 

Included in your purchase is the filter itself, the Aqua Clear foam, the activated carbon filter, cycle guard and biomax. If you’re new to this, let us break it down for you. The water is pumped into the filter and firstly makes its way through the foam/sponge. This foam stops any large pieces of debris from blocking the filter. 

The water then goes through the carbon filter which absorbs all of the bad stuff! Say goodbye to odors and impurities! It then flies up through the biomax filter which promotes the growth of healthy bacteria in your aquarium. Sounds good right?


  • Easy to install. 
  • Purifies water efficiently. 


  • Slightly noisy.

Best Small Aquarium Filter Buying Guide

The Nitrogen Cycle

If you’re about to set up a new aquarium, one of the most important components is the filter. The filter purifies the water and makes your aquarium a comfortable environment for your fish to live in. You may be wondering how it does this, so let us break it down for you below.

As you feed your fish there will be some food that is untouched and will sink to the bottom of your aquarium. Just like any other food, if the food is left there for a long period of time, it will begin to decay. When food decays at the bottom of your tank, it produces harmful bacteria.

What happens when fish eat? They need to go to the toilet! Any excrement will over time, also fall to the bottom of the aquarium. This is not healthy for your tank and will produce ammonia which can have negative effects on your fishy friends.

Ammonia is a chemical toxin and if your tank is not filtered and regularly cleaned, will begin to harm your fish. Ammonia will cause chemical burns to fish tissue and this will usually start off at the gills. Therefore, if you are thinking about getting an aquarium, get a top-quality filter, and regularly change the water.  

A water filter will oxygenate your water and break down the ammonia to make nitrite. This chemical on its own is also harmful to fish but by now, your filter is working properly to ensure that the nitrogen cycle continues. Nitrite then breaks down further into nitrate. 

Nitrate can actually be absorbed by aquatic plants. Once the plants take in the nitrates, the water is purified further as they give out oxygen to the aquarium. The fish will sometimes snack on the plants too so the cycle has been completed and it can start again. A water filter helps to promote this cycle in a small aquarium. 

Types of Aquarium Filters

There are several different types of aquarium filters on the market. We have covered a few variations in our recommendations list but below is a more extensive list of filters available to buy. 

Canister filters are some of the most commonly used filters in medium to large sized aquariums. This type of filter attaches to the outside of your tank and is quite powerful. They work by channeling water through the filter media.

A sponge filter is a good option to create a biological filtration system. It is constructed by pieces of sponge wrapped around an air pump. The sponge captures bacteria and debris which will promote a healthy environment for your fish to flourish in. 

The most common type of filter is a power filter. These usually clip onto the back of your aquarium and come in a wide variety of sizes. This type of filter is great for beginners as they are easy to clean and maintain. 

The clue is in the name with submersible filters. You can fully submerge this filter into your tank. We have recommended some of these filters above as they are easy to install and usually are compact in design.

Suitable Fish Breeds for Small Aquariums

When you have your aquarium set up, it’s a good idea to research what breeds of fish would thrive in your aquarium. You must remember that your tank is a small size so a lot of common fish breeds would not be suitable. For example, a goldfish would not enjoy living in a nano aquarium as they grow a lot larger than you may think. 

We’re going to run through three breeds which would be a good choice for a smaller tank. The fancy guppy is our top choice when looking for breeds suitable for small aquariums. This breed is quite curious and likes to explore any plants or small decorations in the tank. It is best to get a maximum of 6 fancy guppies in one small aquarium so you don’t overcrowd the area. Ensure that you have a good mix of males and females to reduce the stress levels.

Next, we have a popular favourite, the neon tetra. Many aquarium owners love these fish as the neon stripe across their body darts attractively around the tank. It is best to keep this breed in no more than five fish in one small aquarium. It is really important that water is purified regularly so a top quality filter is a must when raising this breed. 

Lastly we have another attractive fish called the zebra danio. Just as the name would imply, the body of this fish is striped black and white. However, the scales are reflective in the water so create an almost light show as they swim back and forth the aquarium. It is best to keep a maximum of five of these guys in one small tank at a time.

Frequently Asked Questions

What is the best way to clean my aquarium?

Cleaning a small aquarium is much easier than cleaning a larger tank. It is much easier to manoeuvre. To start, you need to remove about a quarter of the water in the tank. Then you will need to remove any debris or algae from the tank and decorations. Once this is done, you can start adding in freshly treated water. Then you would have successfully changed your aquarium’s water. 

Once a month, while you are cleaning your aquarium, remove the filter so you can clean that too. It will say how to clean your type of filter in the information booklet that comes with your product. However, in short, you want to remove any stones or debris from the sponge or filter cartridges inside your filter and place back inside the component. 

How often should I clean my aquarium?

How often you clean out your tank depends on several different factors. Size of tank, type of filtration system and the number of fish you have in your tank will all vary for each aquarium. As we are talking mainly about nano or small aquariums in this article, we will say that it is probably best to do this once a week. can