Freshwater Fish for a 10 Gallon Tank

10 gallon fish tanks are perhaps the most popular tank size in the hobby, with many amazing choices and variations out there. They are perfect for beginner hobbyists because they are small, inexpensive, and can be used in an abundance of different ways after serving as your fish tank should you wish to upcycle it.

10 gallon (38 liters) tanks, or nano tanks, as they are commonly referred to as, are fantastic for hobbyists at any stage of their journey due to there still being enough room to create an awesome environment, whilst still being minimalistic.

There is a plethora of different dimensions too, so, if you prefer a tall, narrow tank over a long, short tank, that is totally fine, and more than doable. At the end of this article we have referenced the two most popular size configurations for 10 gallon (38 liters) tanks.

10 gallon freshwater tanks

The only issue with a 10 gallon (38 liters) freshwater fish tank is choosing which fish to have in it! In all cases, the size of your fish tank will determine the size, type, and number of fish you have in it.

So, with any 10-gallon (38 liters) tank, whether that be saltwater or freshwater it is a no-brainer that you will need to populate it with small freshwater or saltwater fish that are of a peaceful nature, and not too many of them.

Best Fish for a Freshwater 10 Gallon Tank

Now, let's dive into the top 5 best fish for a freshwater 10 gallon (38 liters) fish tank. There are plenty of other fish that would be suitable for a tank of such a small size, but the fish on this list are the most beautiful, colorful, and well-tempered fish that will live a healthy and happy life in such a small tank.

Neon Tetras

The Neon Tetra (Paracheirodon innesi) is an incredibly well-known and popular freshwater aquarium fish. They sport almost neon blue bodies, with a bright red stripe starting midway down their body.

These fish are also incredibly small and they enjoy living in large to medium-sized groups, 10 would fit perfectly in a 10-gallon (38 liters) tank as they only grow to around 1.25 inches.

Pregnant Neon Tetra

A recommendation when setting up a neon tetra tank is that you populate it with plenty of plants to hide in, with additional driftwood and rocks to reproduce their natural environment in the streams of South America.

Betta Fish

Betta fish (Betta splendens) is another popular freshwater fish. The Siamese fighting fish come in a huge variety of different colors and patterns and they are extremely easy to care for and manage. They need to be ideally kept alone as they are, as the name suggests ferocious fighters, especially with their own kind.

Goldfish food

Additionally, finding Betta fish tank mates can be a bit of a struggle as they will not play well with most other fish species, especially those that look similar to them, like guppies.

Unfortunately, due to their unique and beautiful appearance, some people use bettas as more of a fashion accessory than they do their fish that must be looked after correctly. An example of this would be people putting bettas in small bowls with no filtration or plants, which is a big, big, no-no.


Guppies (Poecilia reticulata) are certainly beginner-friendly fish, they are incredibly easy to care for and are peaceful by nature, making them a model citizen for any fish community, and you will find no problems when looking for the perfect guppy tank mate.

They will also breed without any assistance, meaning that if you are going to put a few in a 10 gallon freshwater aquarium, make sure they are either all males or all females. If not, they will breed and breed in abundance, unless of course, you want a guppy-only tank or a breeding tank!

Guppy tank mates

You can keep between 5 and 10 guppies in a 10 gallon tank. If you decide to use the small tank as a guppy breeding tank then it is sensible to use the ratio of 1 male to two females.

Male guppies tend to be a lot more colorful than females, but they will all come in many different bright and beautiful colors regardless. By filling up their tank with plants and driftwood you will be ensuring that they live a stimulated and happy life.

Celestial Pearl Danios

Celestial Pearl Danios (Celestichthys margaritatus) is perhaps the most peaceful fish on this list. They make fantastic additions to any pre-existing tank or brand new aquarium. They will only grow to an inch and are the perfect fish for a small, 10 gallon freshwater fish tank.

Celestial pearl danio

They are truly beautiful too, displaying a blue metallic body, covered in bright spots and neon orange bands on their fins. Ideally, they would be residing in a tank with plenty of plants, rocks, caves, driftwood, and any general hiding spots.

They should be kept in schools of 6, but you can definitely have 10 residing in a 10 gallon tank.

There are certainly other brilliant freshwater fish for a 10-gallon tank, including some unusual ones. Even different types of pufferfish (dwarf puffers) can live in a 10 gallon freshwater tank with no issues.

Final Thoughts and Tips

Whilst 10 gallon (38 liters) tanks are some of the smallest in the hobby, there are plenty of stocking options, especially with freshwater tanks.

It certainly helps to have a look around for inspiration, to see what other people have done with their 10 gallon tank, and while it is important to stock yours up with caves and driftwood, you do not want to overcrowd your tank before any fish have been introduced.

Additionally, keeping on top of water changes for your 10 gallon (38 liters) tank is very important. In a small tank ammonia levels and nitrates will build up quickly, which can be detrimental to your aquarium community.

You also need to avoid overfeeding your fish tank, which is much easier to do with a 10 gallon tank.

10 gallon freshwater fish

Finally, 10 gallon (38 liters) tanks come in several different dimensions and sizes, so, if you prefer a tall, narrow tank over a long, short tank, that is totally fine, and more than doable.

The two most popular dimensions for 10 gallon tanks are:

  • 20 inches Long x 10 inches Wide/Deep x 12 inches High (50 cm x 25 cm x 20 cm) for landscape tanks
  • 12 inches Long x 11.5 inches Wide/Deep x 17 inches High (30 cm x 29 cm x 43 cm) for portrait tanks.

The image above displays two popular 10 gallon (38 liters) freshwater fish tank sizes for you to gain some ideas and inspiration from.