You've Got the Fish Tank—Now Which Freshwater Fish Will You Add?
The biggest decision which any aquarist makes when creating a freshwater aquarium is choosing which freshwater fish will populate it. There are so many to choose from! While freshwater accounts for 0.3% of the water on our planet, there are over 15,000 species of freshwater fish and counting. Not all of these are suitable for keeping in home aquariums, and certainly not all are suitable for beginners. So how do you choose?
To give you some ideas, we’ve rounded up some of our favorite freshwater fish for aquariums. We’ve included fish for both amateur aquarists and experts alike. That way, you can find the livestock that's just right for your experience level and tank size.
If you’ve ever known someone with a fish tank, you’ve probably seen a betta fish. One reason they’re so popular is their brightly colored and majestic forms. They were bred to emphasize color and finnage by Asian aquarists over 100 years ago. Today there are many varieties of betta with vibrant colors and patterns, including:
- Crowntail bettas
- Halfmoon bettas
- Butterfly bettas
The betta is commonly seen in small one-fish tanks in the possession of casual fish owners. That’s because the betta requires a minimum tank size of only 3 gallons of water. Compare that to 10, 30, or 50 gallons for other species on this list.
Bettas are alternatively called Siamese Fighting Fish. That's because the males will fight each other to the death if kept together. This also contributes to their often being kept alone, since the males are the ones with the most colorful flowing fins. Male bettas only fight other male bettas though, so females can be kept in groups. In fact, they do best in community tanks with other fish. They require relatively little care and live up to 5 years.
Barbs are another type of fish which comes in a variety of colors and patterns. This makes them good for adding a splash of color to an aquarium. You can choose from many distinct looks from different species, including:
- Black ruby barb
- Rosy barb
- Gold barb
- Checkerboard barb
Cherry barbs have possibly the most eye-catching appearance. Tiger barbs are also eye-catching, but can be more aggressive. Fin-nipping is common. That can be averted by placing them in groups of 3-5. All barbs should be in groups but the numbers vary by species. Cherries are best in groups of 6 or more, for example.
Barbs are good freshwater fish for beginners because they're small and hardy, with high tolerances for condition changes. They’re also very active. However, they take a while to acclimate to new environments, so it can be a few weeks before they start to come out of their shell. Help them out by giving them aquatic plants and other places to hide.
Danios are another small, active fish that loves to dart around in groups. They come in many varieties, including:
- Royal blue danio
- Celestial pearl danio
- Zebra danio
- Giant danio
These are particularly hardy freshwater fish and are great for starting out, since their high tolerance for different water conditions will give you more room for error. However, some danios, like the zebra danio, can bully other peaceful fish, so while they are easy to keep it can be harder to keep them with other species if you put them in a small space where they can get territorial.
Tetras are the most popular freshwater fish for aquariums, and with good reason. They come in many colors—black, silver, gold, and neon hues. Just contrast the Congo tetra and the black skirt tetra.
In addition to that, they’re also pretty easy to take care of. They require relatively little space, with even a school of them being fine in a tank as small as 10 gallons. Throwing together several schools of different species of tetra is an easy way to liven up an aquarium without adding much to the difficulty of maintaining it.
In addition to being easy to care for, they’re also particularly easy to breed. This makes them useful for learning the basics of breeding.
As with the previous entries on this list, guppies are also small freshwater fish which come in a wide variety of colorations. They’re hardy, peaceful, and easy to care for and breed.
They are so easy to breed, in fact, that this can be a nuisance if unintentional. Each female will give live birth to up to 60 fry, and they’re quickly eaten up in a community tank if unsecured. To prevent this, keep only one sex of guppy. We recommend males, as they are more attractive.
Leaving behind the small colorful fish for a moment, let’s take a look at a more useful species—the Plecostomus, a type of sucker-mouthed catfish.
These freshwater fish can attach to a variety of surfaces with their mouths. They like to graze along the bottom of a tank, sucking up unwanted algae and excess food. Because they perform this service so well, they can be quite useful for managing algae.
However, beginners beware: while they look small in the pet store, many kinds of plecos often grow to be a foot long or more. Those are tank-busting dimensions when you consider that most beginners start with a 20-30 gallon tank. A tank should be a minimum of 50 gallons to house a pleco.
7. Cory Cats
If you don’t have that tank space, a corydoras catfish may be a better solution for you.
These guys grow only to around 1-3 inches, and love to mind their own business at the bottom of the tank. There are hundreds of species of cory, and dozens available in stores. You can put a handful of species of cory together and they’ll swim together, scavenging and cleaning the substrate. Just be sure to supplement their scavenging with catfish pellets that sink to the bottom.
8. Kuhli Loachs
This is another bottom-feeding species of freshwater fish. It has the unique advantage of also having a quite distinct appearance. Their eel-like forms are a great addition to diversify the life in your aquarium, and their peaceful and hardy nature makes them good for new aquarists.
Keep them in groups of 3 or more, and try not to pair them with any species that’s too big—they may be mistaken for food.
Cichlids are a vast and diverse group of fish featuring thousands of species found mostly in Africa and in South and Central America. They’re often some of the most colorful species of freshwater fish to be found—but beginners should be wary of the difficulties they can pose.
Many cichlids, like the discus, can please your eyes but make your head hurt with the degree of care they require. They need very specific water conditions, water change schedules, tank dimensions, and plant distributions. They at least are peaceful though, whereas the African cichlids will tear other inhabitants apart, and fire mouth cichlids will get aggressive during mating seasons.
For these reasons, beginners should take a lot of care before deciding to raise cichlids. Yet for intermediate and advanced aquarists who can handle it, the brilliant hues of cichlids like the peacock cichlid are well worth the effort.
Gouramis are another group of freshwater fish that come in a wide variety of colorations and patterns. Some of the most distinct include:
- Red fire dwarf gouramis
- Banded gouramis
- Lace gouramis
- Blue gouramis
There have been plenty of colorful fish on this list, though. Gouramis are more interesting in their behaviors. All gouramis swim to the top of the water and take gulps of air, so you should allow room at the top of the tank for them to do that. This allows them to live in water with less oxygen. Different kinds of gouramis also exhibit other interesting behaviors, including spitting jets of water, chirping and croaking during social interaction, and feeling around with long needlelike fins.
Other Freshwater Fish
There are still thousands of freshwater fish to choose from, including platies, mollies, sword tails, angelfish, and so much more. These are some of our favorites, but here's a more extensive list of 101 species.
If you’re looking for a reliable supplier for these fish, or want advice on building your aquarium’s community, then Living Art Aquatics in Crystal Lake has the expertise you need. We've been working with these and other species for years. Give us a call and we’ll help set you on your way to a vibrant, colorful aquarium.
This post was originally published in August 2016, and has been updated for accuracy and comprehensiveness.