20 Best Freshwater Aquarium Fish

Finding the right fish for your aquarium can be a pain, especially if you’re new to the hobby. So, we’ve set up a list of some of the best freshwater aquarium fish around and included a little bit about their care to boot.

So, read on and we’ll help you find the right fish to fill the missing niche in your tank!

freshwater aquarium fish

Best Freshwater Fish for Beginners

1. Betta Splendens – Best Fish for Beginners

The humble Betta sure gets a lot of press. They’re one of the most common species in the trade and they display an outstanding amount of colors alongside their flowing fins. They’re also the first fish I recommend to people.

Reasons for keeping a Betta first are numerous. The most important, in my eyes, is that they’re low maintenance while remaining attractive. Many of the larger colorful fish, such as Discus, are hard to care for and require huge tanks.

Meanwhile, a Betta can live happily in a 5-gallon tank with a small filter. They’re interactive, curious creatures. The only real issue is that you can’t keep males together or they’ll kill each other due to their strong breeding instincts.

Small tanks, small fish, big personality, and easy care? It’s hard to beat a Betta for someone new to the hobby. You can find out more about their care right here.

2. Fancy Guppies – Best Schooling Fish for Newbies

Guppies are, hands-down, one of the most common and colorful of the various varieties of livebearer. I think their small size and extra hardy nature make them a great beginner choice. You can fit 6 in a 10-gallon tank with no issues.

You can breed them with no effort. And, while I don’t advise it, you can usually cycle a tank without any deaths. That’s a good thing if you happened to bring some home and didn’t have the proper education first, as often happens with fish purchased for kids.

They’re also one of the best places I can think of to learn selective breeding. The generations emerge quickly and there are obvious changes. It’s a great project for kids and a good starting place for adults who’d like to step into larger and more lucrative fish.

Overall? Guppies are a learner’s fish and they do quite well in that role. If you want schooling fish for your first go-around, you won’t find any fish easier to care for.

3. Oscar – Best Cichlid for Beginners

This may be a controversial pick, but I honestly believe there’s no better place to start with Cichlids than to pick up an Oscar. Just make sure you have a tank big enough for him, those cute little 2” Tiger Striped Oscars are going to end up being a bit over a foot long.

And a lot uglier, but I think that’s true for all of us.

The fact of the matter is that Oscars are almost invariably captive-bred, highly tolerant of water conditions, and they’re tough overall. The last one is a big point if you start an actual tank for cichlids, balancing aggression levels in these tanks is a headache for newbies.

The best part is that they’re highly intelligent and interactive with their owners if they feel secure. This allows you to learn a bit about cichlid communication and behavior. For instance, Oscars clearly display moods and communicate with color. Mine was the first fish I ever considered a real “pet” due to that.

Overall? This American cichlid is one of the most interactive fish around. They make a great introduction to cichlids in general, and they’ll interact with you whenever you’re near the tank. It’s a win for everyone, and they’re still gorgeous even if you choose not to expand to other areas with the genus.

4. Corydoras Catfish – Best Bottom Dweller for Beginners

The humble Corydoras Catfish is an awesome little fish. They school together, act lively, and come in a bunch of different varieties. Their care is easy enough for even a true amateur and they’re pretty tolerant of beginner mistakes.

Just keep in mind that you’ll need a 10-gallon tank just for them since they should be kept in groups of five or more. If you’d like to add some guppies as well you should probably go ahead and pick up a 20-gallon tank as well.

The only real requirement for their care is paying attention to the substrate of the tank so their delicate barbels aren’t harmed. You’ll have to skip the clown puke and gravel, but it’s definitely worth it.

For those considering it, I recommend looking at our guide to the Panda variety. Care is the same across the board. It’s hard to describe just how cute they are in groups, so just pick up a group and you won’t have to take my word for it.

5. Cherry Barbs – A Great Addition for Planted Tanks

Planted aquaria are their own subject. Everything on the list so far, except for the Oscar, do well in them but some fish excel. The Cherry Barb is my personal favorite schooling fish for any kind of planted tank.

They’re relatively sedate for the most part. Unlike most barbs, they tend to be peaceful and only occasionally fight among themselves. The males are an impressive red that can be enhanced by feeding them blood worms on occasion.

They’ll gently nibble at algae from time to time, but they’re 100% harmless to your plants. Their sedate movements are relaxing, creating an even more picture-perfect scene in a well-done planted tank.

If you’re unsure of what fish to put in your planted tanks? Cherry Barbs are where you should go. Add a few Cherry shrimp as well and you’ll have a low-maintenance display tank with just enough red to keep things interesting.

Best Freshwater Fish for Nano Tanks

6. Celestial Pearl Danio

The Celestial Pearl Danio is one of the newer nano-fish available to aquarists, and they’re pretty nifty little critters. These fish only reach about an inch at most, and they do well in the confines of smaller aquaria.

These fish sport a black, spotted body with bright red fins. They were first described in 2006, which means they’re not as well studied as most fish. That said, they thrive in captive care without requiring anything specialized.

They’re an excellent addition to small planted tanks, providing movement and a bright splash of color. The only issue in their care is that they’re remarkably shy, so you may want to keep them in a single species tank in groups of five or more for the best results.

While a newcomer to the stage, Celestial Pearl Danios are quickly becoming a favorite in the hobby.

7. Endler’s Livebearer

Imagine, if you will, a smaller guppy that still has bright coloration but can be fit into a nano-sized tank without issue. That’s the Endler’s Livebearer, an easy-to-keep and breed fish that’s a staple in nano-tanks.

Endler’s have a wide variety of different colors, which track about the same as guppy colors. That makes them suitable for amateur breeders who want to begin to understand selective and line-breeding on a larger scale.

They’re also lively. You just need to make sure that you balance out the males and females in the right ratio for the best results. Two females per male is a bit less colorful, but it’ll make everyone in the tank a lot happier and increase the chances of breeding success.

They’re some of the most popular nano fish for a reason, I’d suggest taking a look if you’re starting your first nano-tank and don’t know where to start.

8. Otocinclus Catfish

The Otocinclus Catfish is perhaps the algae eater when it comes to small planted aquariums. They’re also easy to keep if you follow some simple guidelines regarding the tank you place them in. Namely, it needs to be a mature tank.

If provided with biofilm and some hiding spots, however, these fish will devour algae voraciously. They’re remarkably active for sucker catfish as well, and a small group of three or more can be a lot of fun to watch.

Do your research before adding them. The mature tank isn’t optional to their care, but instead 100% crucial to their survival in the long term. Manage that, however?

And you may have just found the best algae eater for nano-tanks around!

9.  Chili Rasbora

Chili Rasboras are another one of the great fish that you can easily fit in a nano-tank. They’re hardy, but they do have some trouble with nitrates, so you’ll need a clean, cycled tank to keep them. If you’ve got that?

Well, you’re good to go. These fish are hardy, active, and their bright crimson coloration contrasts well with heavy planting. Captive-bred specimens are about as hardy as any other schooling fish, at least when it comes to pH and water hardness.

In my opinion, any freshwater nano-tank should be planted, and the plants do a good job at soaking up excess nitrates. It does mean that you have to test regularly and do regular water changes, but the end result is spectacular.

Give them a shot if you’re looking for something colorful for your small tank.

10. Clown Killifish

Clown Killifish, also known as the Banded Panchax, is a small, bee-striped fish that remains under 1 ½” as it matures. This makes them an ideal fish for those interested in nano-tanks, but they may not be the best choice for a complete amateur.

These fish thrive in a cycled, clean nano-tank. The biggest problem you’ll encounter in their care is that they’re not particularly tolerant of high-flow conditions so you’ll need plants to help keep the water clean. That’s pretty much a given in a nano-tank, regardless of the inhabitants.

These fish are a bit shy, so you need plenty of cover and some caves. You’re also best off keeping them as the only species of fish in the tank, although they’ll peacefully coexist with Neocardinia davidii or other dwarf shrimp.

While a little bit more challenging than some, keeping Clown Killifish can be very rewarding. They’re worth a look if you’re planning on setting up a small tank in the future.

Best Brackish Fish

11. Bumblebee Goby

The Bumblebee Goby is a tiny, brackish water fish that has bold coloration and a big attitude. These fish reach about 1 ½” at most and they’ll spend most of their time peacefully floating about. They’re usually kept in a species-only tank to avoid problems with predation.

On the other hand, you can’t keep them with things like dwarf shrimp. Their voracious appetite for crustaceans extends to those the same size as themselves, stick with larger shrimp if you choose to go down that route.

That said, they’re among the only brackish water fish that are suitable for small-scale aquaria. Tank mates are their biggest problem, however, the Bumblebee Goby is an adaptable, hardy fish that is suitable even for those new to introducing a bit of salinity.

They’re a great way to enter the world of brackish fishkeeping, and they’re a fast favorite among many of us. It’s hard to beat watching a trio of these guys scoot around a properly maintained 5-gallon aquarium!

12. Figure 8 Puffer

Puffers are all great fish, but for my money, the best commonly available one is the Figure-8 Puffer. They’re on the small end for a pufferfish, at about 2 ½”, but their great coloration and lively nature make them a favorite.

They’re also, in my experience, less aggressive than the slightly smaller Pea Puffer. That makes them a suitable (but not ideal) candidate for a mixed tank, as long as you’re mindful of the fact their beak can do serious damage to larger fish.

I’d still advise keeping them in a species only tank. As with all puffers, most invertebrates are a complete non-starter. A puffer this size will tear apart crayfish, fiddler crabs, and other common freshwater invertebrates with no problems.

That said, they’re amazing in a species-tank. After a few days, you’ll quickly realize just how intelligent and curious these cute little guys really are. Just be aware they’ll be a lot less cute if you stick the wrong fauna in alongside them.

13. Mudskipper

Specialized tanks and specialized care turn a lot of people off of mudskippers, but they’re still one of the more commonly found brackish Goby species. A turtle dock, good hood, and a 40-gallon breeder tank are actually enough to keep them in most cases, however.

Mudskippers are a fish species, despite spending a bit of time on land. They can jump so be prepared with a full hood before you introduce them. More than one has met their fate by drying out on carpet somewhere. That said, there are few fish more amusing to watch.

Mudskippers are predatory, territorial animals despite the fact they look like real-life Pokemon. They should be housed on their own, separate from other species and invertebrates. They need their space, but apart from needing a vivarium, they’re quite easy to care for.

If you want something truly unique in your home, mudskippers are a great option! Just be aware of their nature before you choose to bring them home.

Best Algae Eaters

14. Common Plecostomus

The Common Plecostomus gets a bad rap. They usually end up either being looked over entirely or being recommended to newbies who don’t realize how large they get. A full-grown Pleco can reach 15” or a bit more. These days, with more education, most people with smaller tanks opt for a Bristlenose Pleco instead.

But if you have a large tank? The Common Plecostomus is a powerhouse of algae-eating. They can take hits from all but the nastiest of freshwater fish without an issue, including American cichlids like Oscar and Green Terror. Their armor is thick, and they’re extremely strong. Most fish decide it’s not worth tangling with them quickly.

That makes them an excellent all-purpose algae eater in tanks 55 gallons or more. They’re also active, curious creatures which is surprising since most consider them more of a fixture than a pet. They adapt to water conditions better than most freshwater aquarium fish, they’re long-lived, and generally great fish to have around.

If you have a larger tank and need to handle an algae problem? The Common Pleco may be just who you’re looking for.

15. Siamese Algae Eater

Let’s get one thing clear right from the outset: the Siamese Algae Eater and Flying Fox look very similar. The Flying Fox is still a great fish in their own right, but they don’t even crack the top 10 algae eaters for the freshwater aquarium. You should know the difference before you buy one.

SAEs are the only fish I know of that consistently eat black beard algae, an insidious and hard-to-handle form that shows up in freshwater tanks. They seem to love the stuff, but the usual suspects won’t touch it. A Flying Fox may nibble, but they won’t rid your tank of it in the same way.

One thing to be aware of with SAE is the fact that they can be a bit aggressive… with fish that want to fight back. Fish like guppies, tetra, and most danios won’t have any trouble with them. As long as the fish respect their little bit of territory all will be well.

Aside from that, there are no real problems with keeping them. They’re hardy, durable, and long-lived… plus they’ll destroy any algae in sight. That makes them among the best algae eaters available for your freshwater tank.

Best Coldwater Fish

16. Ruby Red Minnows

Ruby Red Minnows are a common feeder fish. I’ve fed hundreds of (carefully quarantined and gut-loaded) them to larger cichlids and other big predators over the years. They’re also great coldwater fish, with an attractive coloration and tight schooling behavior.

Their resistance to lower temperatures makes them a common pond fish as well. The cool part is that they’ll take almost any water condition without complaint, and when fed with a few bloodworms they’ll become much darker than they are in the store.

They’re cheap, but the main problem is finding healthy fish. These fish are primarily sold as feeders, which means bad conditions in many stores despite the risk that puts on the fish eating them. You can usually nurse them back to health easily, but make sure to have a quarantine period as ich and other diseases run rampant in the same conditions.

But, if you’re looking for a colorful coldwater fish? Ruby Reds are readily available and hard to beat.

17. Gambusia

The humble mosquitofish is another one that commonly finds itself in ponds. They’re considered necessary mosquito control in many areas, particularly in manmade ponds without high circulation. They rapidly devour any mosquito larvae in their vicinity.

That said, you don’t want to keep these 3” fish with peaceful fish in the same size range. They’re a bit nippy and can stress out the majority of small schooling fish. I’ve found they’re amazing fish for small aqua-gardens, however, in the 10-25 gallon range. Whether in an aquarium or an above-ground pond.

They’re hardy on a level just not found in tropical fish. Able to stand low oxygen, dirty water, and terrible conditions. You shouldn’t let conditions get that bad, but they can be a good introduction for newbies who take livestock deaths personally.

While not the flashiest fish out there, the Gambusia should be in consideration for any coldwater gardens you’re planning on running, especially if you prefer to just enjoy the plant life without additional color.

18. White Cloud Minnows

I may be biased, but I’m pretty sure White Cloud Minnows are the best coldwater fish for indoor aquariums. They’re small, have just a hint of color, and lively movement as long as they have a  large enough school to feel secure.

These little guys only get 1 ½” long, making them suitable for nano-tanks, and with the removed need for a heater they’re my go-to choice for desktop tanks. They’re considered endangered in the wild, and captive breeding programs are being used to reintroduce them to their native climate.

On our side of things, however, they’re hardy and attractive fish that don’t require any specialized care. Think guppies without the need for a heater and you’ll be on the right track to making them thrive. Although they’re egg-scatterers, not live-bearers when it comes to breeding.

The humble White Cloud Minnow is among my top fish, period. You might find that you think the same after introducing a school into your home.

Best Oddball Freshwater Fish

19. Black Ghost Knife

The Black Ghost Knife is unlike… well, any other fish for the most part. All it takes is some video of one swimming to fascinate most people. Fortunately, if you can make some simple concessions for their care they’re actually easy to care for.

These fish are entirely blind, instead of using an electric sensory organ to find their way around.  They can reach 20” in length but grow quite slowly if you’re willing to plan for a grow-out tank in the future. They are predatory, so be very selective if you’re keeping them with other fish. They strike when it’s dark, so even speed isn’t assurance against their hunger.

A BGK will spend a lot of time in its cave, making them hard to observe in some tanks. My favorite way to get around it is to place a 2 ½” plastic tube at the front of the tank. The fish are blind and will still feel secure while you’re observing them.

If you have the space to take care of one, these incredible fish can be a great addition to the home. It’s hard to get something so odd with such easy care requirements, and they’re a borderline staple in LFS’ across the country.

20. Tire Track Eel

One of the many faux-eels available, the Tire Track Eel is the most docile of those I’ve kept. You do need to learn how to seal your tank nearly 100% to keep an eel successfully, but with the right habitat, they’re a lot of fun to watch.

You’ll need a soft substrate for these guys. They prefer to spend their time sifting in the sand, and even hiding in it, rather than swimming in the open. They’re best kept alone or with only a few fish large enough for them not to eat, especially if you want to observe them.

While their tank needs to be specialized, they’ll eat pretty much any frozen food and aren’t demanding about water conditions. A clean, cycled tank will easily support an appropriately sized eel. They’re a good beginner fish for those wanting to keep oddballs instead of the usual suspect.

The Tire Track Eel is a lively, unique addition to your home. Just be careful about tankmates and make sure your hood is on tight and they’ll enjoy a long, happy life while you watch.

Some Great Fish, But Not All of Them

Finding the best freshwater fish for your aquarium can be challenging. I hope the above has given you some stocking ideas for your next tank, and maybe even convinced you to break into something new.

There’s a world of fish out there, but the above are some of my favorites and I hope they’ll be yours too!