A 10 gallon aquarium might be the most popular tank size in existence.
You can think of a 10 gallon tank as the Honda Civic of aquariums—practical and widely available.
The reason that 10 gallon tanks are so poplar (according to me), is that they provide an excellent balance between size, price, and space available for fish.
10 gallons tanks are widely available and are often a “first time” tank for families and people new to fishkeeping.
Does that mean you should get a 10 gallon tank?
That depends on which fish you plan to keep.
10 gallon tanks make ideal homes for a wide range of tropical fish species, but, because 10 gallon tanks look so spacious, new fishkeepers often make two giant mistakes:
1. Overcrowding; and
2. Incompatible species.
Overcrowding a new tank with fish leads to ammonia spikes, and the death of most, if not all, of the fish.
And, putting incompatible species in a tank together may lead to fin nipping, stress, or death.
A classic mistake is to keep goldfish (a coldwater fish) together with tropical fish (like neon tetras).
The result is usually a bunch of dead fish.
Another common concern is that 10 gallon tanks are too small for many commonly kept schooling fish.
And that is often true. Most schooling fish are not ideal for small tanks like a 10 gallon.
But, some schooling fish do well in 10 gallon tanks, and, in my experience, how well these fish do depends more on water quality and having places to hide than on total water volume.
Think about it this way, the dimensions of a standard 20 gallon tank are 24 inches by 12 inches by 16 inches.
And, a standard 10 gallon tank measures 20 inches by 10 inches by 12 inches.
This means that a 20 gallon aquarium only offers 4 extra inches of length, 2 extra inches of width, and 4 extra inches of height for the fish to swim compared to a 10 gallon tank.
Many people think larger tanks offer more room to swim, and they do to a certain degree, but the real difference between a 20 gallon aquarium and a 10 gallon aquarium is the extra water volume in a 20 gallon.
That may sound obvious, but many people worry more about giving their fish a couple inches of extra swimming space rather than focusing on keeping the water stable and clean.
So, what all this means is that many of the fish suitable for a 20 gallon aquarium are also suitable for a 10 gallon aquarium if water conditions are kept pristine.
Which Fish Are The Best Fish To Keep In A 10 Gallon Tank?
And which fish should be avoided?
This article will help you pick the best fish for a 10 gallon tank; keep in mind that these are not the only fish that are suitably kept in a 10 gallon, they are just some of my favorites.
1. Black Skirt Tetra (Gymnocorymbus ternetzi)
Recommended Temperature: 74-80 Fahrenheit (23.33-26.67 Celsius)
Size: 2-3 inches (5-7.6 centimeters)
Black Skirt Tetras, also known as Black Widow Tetras or Petticoat Tetras, are a classic aquarium fish, and are found in most pet stores that sell tropical fish.
And for good reason, Black Skirt Tetras are hardy and tolerate a wide range of water conditions.
They are also elegant, typically sporting two vertical black stripes along their bodies.
Some have even been bred with longer fins, giving the fish an especially graceful look.
Black Skirts are schooling fish, and enjoy swimming in groups.
But, room is limited in a 10 gallon tank, so how many Black Skirt Tetras are suitable for a 10 gallon aquarium?
My answer is 3-4 fish.
That answer may be controversial to some, but a 10 gallon and a 20 gallon tank are not far off in terms of dimensions (see my explanation above).
That being said, comfortably keeping 4 Black Skirt Tetras in a 10 gallon tank means frequently changing the water and providing plant cover and a solid filter.
Is this the most ideal setup for these fish? Maybe not, but in my experience they thrive in 10 gallon tanks and may even breed.
If you want a large school of these fish, consider getting a 40 gallon breeder tank (a 30 gallon tank is also a great option).
2. Swordtail Fish (Xiphophorus helleri)
Recommended Temperature: 72-80 Fahrenheit (22.22-26.67 Celsius)
Size: 3-5 inches (7.6-12.7 centimeters)
Swordtails (Xiphophorus helleri) are live bearing tropical fish with pointy tails, hence the name “swordtail.”
These fish are perfect for someone who wants a fish with the personality of a guppy (active and a little crazy), but larger and more streamlined.
Female Swordtails do not possess a pointy tail, and look similar to a Platy (fish) in body shape.
Swordtails are available in a variety of colors, with certain colors fetching higher prices than others.
Swordtails, like most commonly kept livebearers, are extremely hardy and will fill your tank with babies if males and females are kept together.
In a 10 gallon tank, keeping a group of 3 males is best if you don’t want to be removing and rehoming fish fry.
Swordtails look stunning in a planted tank setup, and plants also provide places for your fish to hide if one of them becomes aggressive.
3. Bleeding Heart Tetra (Hyphessobrycon erythrostigma)
Recommended Temperature: 72-82 Fahrenheit (22.22-27.78 Celsius)
Size: 2-3 inches (5-7.6 centimeters)
The Bleeding Heart Tetra is a beginner friendly community fish with a conspicuous red dot near the middle of its body.
The fish is not actually bleeding, and the red dot is not a heart, so don’t get freaked out by the name.
Like the Black Skirt Tetra, these fish are hardy and make excellent fish for new aquarists.
If you want a fish that looks interesting but is also easy to keep, consider getting 3-4 Bleeding Heart Tetras for your 10 gallon tank.
If you want to keep more than that number, consider getting a 30 or 40 gallon tank.
4. Sparkling Gourami (Trichopsis pumila)
Recommended Temperature: 76-82 Fahrenheit (24.44-27.78 Celsius)
Size: 1.5 inches (3.81 centimeters)
Also known as the Pygmy Gourami, these fish are sometimes mistaken for the Croaking Gourami, which is a different species (Trichopsis vittata).
While not a true schooling fish, Sparkling Gouramis enjoy being in groups of 4-6.
In a 10 gallon tank, a group of 1 male and 2-3 females works well.
If you plan to keep more than one male, consider getting a 30+ gallon tank as male gouramis will compete for territory in the tank.
They are mesmerizing to watch, and constantly interacting with each other.
Sparking Gouramis have surprisingly large eyes for a small fish, which makes them seem more intelligent and alert (at least to me) than other commonly kept aquarium fish.
They are somewhat shy fish, and enjoy hiding in plant cover, so make sure your tank has some aquatic plants.
Sparkling Gouramis reach a maximum size of about 1.5 inches, making them one of the only gouramis suitable for a smaller tank, like a 10 gallon.
5. Gold Barbs (Barbodes semifasciolatus var. Schuberti)
Recommended Temperature: 68-80 Fahrenheit (20-26.67 Celsius)
Size: 3 inches (7.62 centimeters)
Gold Barbs are magnificent tropical fish with bright yellow bodies speckled with black dots.
Also known as the Chinese Barb or Schuberti Barb, the Gold Barbs we see in the aquarium hobby were line bred by Thomas Schubert.
Gold Barbs are active fish and do best in schools, so for these fish a 20 gallon long aquarium (extra length) is better than a standard 10 gallon.
Given their size, keeping 3-4 fish in a 10 gallon is certainly doable, but make sure to perform frequent water changes.
Gold Barbs are beautiful fish and perfect for aquarists who appreciate Goldfish but want a much more reasonably sized fish that can comfortably live in a 10 gallon.
6. Marbled Hatchet Fish (Carnegiella strigata)
Recommended Temperature: 76-80 Fahrenheit (24.44-26.67 Celsius)
Size: 1.25-1.75 inches (3.18-4.45)
Marbled Hatchet Fish are surface dwelling fish with unique body shapes, kind of like a turkey’s waddle.
Hatchet fish are fascinating because they are considered a type of flying fish.
These fish are incredible jumpers and can actually flap their pectoral fins while airborne.
In the fish world, this is as close to flying as it gets.
If you plan to keep these amazing fish, make sure you have a tight fitting lid on your aquarium.
Marbled Hatchet Fish are on the smaller side when it comes to hatchet fish, seldom reaching over 1.75 inches.
They are also one of the most common species of hatchet fish in the aquarium hobby, making them relatively easy to find and affordable.
Being nervous, Marbled Hatchet Fish enjoy being in groups.
In a 10 gallon tank, a group of 4-5 hatchet fish works well, especially if the tank contains floating plants.
If you plan to keep more than that number, or if you plan to keep your hatchets with other fish, consider getting a spacious 30 or 40 gallon tank.
In general, caring for Hatchet Fish takes a little more work than other commonly kept community fish.
These fish eat at the water’s surface so make sure to offer them foods that are easy for them to grab at the surface.
Offering a variety of foods like tubifex worms, fruit flies, and protein flakes will help keep them healthy.
Also, if other fish are in the tank, make sure your Hatchet Fish are actually eating, and not having their food stolen.
7. Betta Fish (Betta splendens)
Recommended Temperature: 78-80 Fahrenheit (25.56-26.67 Celsius)
Size: 2.25-2.6 inches (5.72-6.6 centimeters)
Betta Fish are just too magnificent to leave off this list of best fish for a 10 gallon aquarium.
Does a betta need a 10 gallon tank to himself/herself? Not really.
Is it good for a betta to live in a 10 gallon tank? Yes.
The extra water volume is helpful for maintaining water quality, and betta fish do enjoy exploring so the extra space gives them some extra enrichment.
Also, a 10 gallon tank is perfect if you plan on giving your betta fish some tank mates.
Betta fish don’t require tank mates, they are perfectly happy on their own, but a 10 gallon provides enough space to keep some small tank mates, like pygmy corydoras, or some large snails.
But remember, betta fish are aggressive, do your research before putting a betta in a tank with other tropical fish.
For a list of fish that can live with a betta fish, check out my article on betta fish tank mates.
8. Pygmy Cory Catfish (Corydoras pygmaeus)
Recommended Temperature: 74-80 Fahrenheit (23.33-26.67 Celsius)
Size: up to 1 inch (2.54 centimeters)
Corydora Catfish are little bottom dwellers that roam around the tank looking for bits of food.
Corydoras are shy tropical fish and do best in groups of 4 or more.
For larger species of Corydora Catfish, a 10 gallon is not ideal as surface area is limited.
But, for Pygmy Cory Catfish, which typically refers to three species of small corydoras (C. pygmaeus; C. hastatus; C. habrosus), a 10 gallon tank is excellent.
C. pygmaeus is the smallest and my favorite, but the others species also do well in a 10 gallon setup.
Pygmy Corydoras are relatively easy to keep, but make sure food is actually reaching them at the bottom of the tank.
A varied diet is also important for the health of these small but captivating aquarium fish.
Pygmy Cory Catfish make ideal tank mates for a variety of tropical fish, including betta fish, making them one of the best cleanup crews for small tanks.
9. Guppies (Poecilia reticulata)
Recommended Temperature: 74-80 Fahrenheit (23.33-26.67 Celsius)
Size: 2 inches (5.08 centimeters)
Guppies are, without a doubt, one of the best fish to keep in a 10 gallon aquarium.
They are relatively small, which lets you keep multiple fish without creating major water quality issues.
They are active, and constantly excited by the prospect of food.
And, they are available in a huge array of colors.
If you want an elegant fish, that can only be described as happy go lucky (as far as fish go), then get some guppies for your 10 gallon.
The one downside of guppies is that they breed like rabbits.
If you don’t want a tank full of small guppy babies, consider keeping only a group of male guppies in your tank.
If you want to learn more about the differences between male and female guppies and which is better to keep, read my article on male vs female guppies.
Guppies also made it onto my list of the best fish for a 5 gallon tank, which you can check out here.
10. Mollies and/or Platies
Recommended Temperature: 76-80 Fahrenheit (24.44-26.67 Celsius)
Size: 3-5 inches (7.62-12.7 centimeters)
Mollies and Platies make this list of the best fish for a 10 gallon because, like Swordtails and Guppies, they are resilient and enjoyable to keep.
Whether you get Balloon Mollies, or Mickey Mouse Platies, or one of the other innumerable colors available, these tropical fish are ideal for 10 gallon tanks.
Both fish are reasonably sized; Mollies typically stay under 5 inches, and Platies tend to max out around 3 inches.
Being livebearers, these fish will breed prolifically if given the chance, so keep that in mind if you plan to keep male and female fish together.
If you are new to fish keeping, or if you are looking for “easy” fish to keep, consider getting 3-4 mollies or platies for your tank.
Conclusion
Picking the perfect fish for your 10 gallon tank is challenging because a wide variety of personable and beautiful fish are available these days.
You really can’t go wrong with any of the fish listed above, but keep in mind that some fish do well with tank mates and some do better alone, or with invertebrate tanks mates only.
Most of the fish in this article can be kept together but, some combinations—such as a betta fish and guppies, or a betta fish and gold barbs— are likely to end poorly.
If you want to learn more about betta fish and which fish can safely be kept with them, check out my article on betta fish tank makes.
If you want to aquascape your 10 gallon tank, check out my article and video on creating a cave aquascape in a 5 gallon, the same setup can be replicated in larger tanks.
Finally, if you love small tanks, check out my article on best fish for a 5 gallon tank.
As always, stay zen.