10 Best Large Fish for a Freshwater Aquarium - PetHelpful - By fellow animal lovers and experts
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10 Best Large Fish for a Freshwater Aquarium

Eric is an aquarium enthusiast with over two decades of experience caring for a wide array of tropical fish.

Big fish like Oscars are fun to keep but require the correct size aquarium.

Big fish like Oscars are fun to keep but require the correct size aquarium.

Large fish look amazing in a freshwater aquarium. Whether they are a centerpiece fish in a community tank, part of a huge aquarium setup, or have their own single-specimen tank all to themselves, a big fish grabs your attention.

In the aquarium hobby, there are many cool large fish to choose from, but you’d better do your research before bringing them home. If you skip that important step, you might find yourself in over your head with a monster fish that’s outgrowing its tank and perhaps eating all of its tank mates.

This article can help. Here you’ll find a list of ten of the most commonly available large freshwater fish. Odds are you can zip on down your local pet store and purchase any of them right now. But should you? By the time you are done reading this you ought to know the answer to that.

At the top of the list you’ll find fish that are easy to care for and can be kept in a standard-size aquarium in your home. They are among the best fish for a 55-gallon tank setup. As you move further down the list, you will see fish with some special housing requirements you absolutely need to consider before you bring them home.

1. Angelfish

Freshwater Angelfish are extremely popular in the aquarium industry. They are new-world cichlids and come in a variety of colors and patterns. The angelfish is a great choice as a centerpiece fish in a 55-gallon tank but be sure not to stock small fish as they could become a snack. A well-planted aquarium with plenty of driftwood and swimming space recreates the angels’ home environment in the Amazon and looks fantastic. Avoid stocking your angel with fin-nippers or aggressive fish. While they grow to a large size, angelfish aren’t fast moving, and their flowing fins can be irresistible to smaller fish like tiger barbs.

Maximum Size

12 inches (tall)

Minimum Tank Size

55 gallons

Tank Setup

Live plants, driftwood, river rocks, plenty of swimming space, low-moderate current.

Tank Mates

Large, peaceful fish; medium-sized schooling fish, bottom dwellers such as cories.

2. African Leaf Fish

The African Leaf Fish is one of my all-time favorite fish and among the most colorful freshwater fish you can add to your aquarium. It is the ultimate ambush predator and comes complete with its own camouflage. It lurks in the vegetation, waiting for prey to swim past, and then gulps it into its massive mouth. That means you don’t want to stock this fish with anything you don’t want it to eat, and that includes most fish smaller than it. Incorporate lots of vegetation and live plants as that is where the African leaf fish will spend most of its time. Also avoid stocking aggressive fish. While the African leaf fish is a predator, it is otherwise a docile fish.

You may see the African leaf fish referred to under different names, including:

  • Leopard Bush Fish
  • Spotted Ctenopoma
  • Leopard Ctenopoma
  • Spotted Climbing Perch

Maximum Size

8 Inches

Minimum Tank Size

55 gallons

Tank Setup

Lots of live plants and vegetation for hiding.

Tank Mates

Large, peaceful fish too large to eat. Avoid other anabantids (gourami, betta, etc).

3. Oscar

Oscars (Astronotus ocellatus) are large, aggressive new-world cichlids. They can live for a couple of decades and grow to a foot. So, if you are thinking about getting one, you are in it for the long haul. Some fish keepers house the oscars in pairs, but often these predatory fish are best kept in single-specimen tank. Include plenty of room for swimming and some driftwood. Know that they may try to uproot any plants, live or artificial, if you include them be sure they to secure them. A 55-gallon tank is the bare minimum for one of these guys, but a 75 gallon would be better.

Maximum Size

14 inches

Minimum Tank Size

55 gallons (single-specimen tank)

Tank Setup

Driftwood, river rocks, lots of swimming space. May uproot live plants.

Tank Mates

Other oscars. Often best kept as single-specimen.

4. Common Plecostomus

Plecos are the “sucker fish” you see clinging to the sides of an aquarium. They are among the best freshwater algae eaters and for that reason, juveniles of the species end up in many novice fish keepers’ tanks. The problem, besides the fact that there are better ways to deal with algae, is that the common pleco can grow to a foot and a half or more in length. That’s way too big for most home aquariums. In fact, if you want a common pleco you need to be thinking of a tank 150 gallons or bigger. If that sounds a little crazy but you still like having a sucker fish, consider instead a rubber-lip pleco, which only grows to about six inches.

Maximum Size

24 inches

Minimum Tank Size

150 gallons for common pleco

Tank Setup

Plenty of driftwood and hiding spots. Plecos are tough on live plants. Consider artificial instead.

Tank Mates

Large fish as adult. Any tropical fish as juvenile. Plecos may become more aggressive as they age.

5. Silver Dollar

These round fish often look more like silver quarters in the pet store. However, silver dollars can grow to six inches across. They are a relative of the piranha, but they are peaceful omnivores. That means you don’t have to worry about them gnawing on your hand if you stick it in the tank, but they may much up your live plants. They are also schooling fish and they do well in small groups. While they won’t need a massive tank like the bala sharks or tinfoil barbs, you should still be thinking of a tank around 100 gallons for a school of these guys. Long tanks are best as they are active swimmers. Consider other large, peaceful tank mates.

Maximum Size

6 inches

Minimum Tank Size

100 gallons (school of 6)

Tank Setup

Long tank with few obstacles. River rocks. Silver dollars may eat live plants.

Tank Mates

Other South American species; medium-sized fish they can't eat.

6. Clown Loach

The clown loach is a bottom dweller who can help tidy up some uneaten food that falls to the bottom of your tank. They are also a fish known to eat snails. They may become aggressive if kept in insufficient numbers, so aim for a small school of six. Because they reach an adult length of about a foot, that means you will need a enormous tank of at least 150 gallons. The clown loach is another fish you can easily purchase as a small juvenile. They are beautiful fish, but few people know what they are getting when they purchase them.

Maximum Size

12 inches

Minimum Tank Size

150 gallons (school of 6)

Tank Setup

Driftwood, rover rocks. Plenty of swimming space at lower levels of tank. Loaches are nocturnal so hiding spots are a must. May uproot live plants.

Tank Mates

Large and medium-sized fast-moving fish.

7. Bala Shark

Bala sharks are beautiful, peaceful fish, with silver sides and a streamlined form. You can buy them in most pet stores as little 3-inch juveniles and they are very tempting, but this is a situation where you want to do your research before purchasing. Adult bala shark can grow to over a foot. To complicate things further, they are fast-moving schooling fish that require a lot of swimming space and need to be kept in groups of six or more. So, how big of a tank do you think you need for six foot-long fish that like to swim around a lot? If you answered really, really big, you are correct. While they can live in a 55-gallon tank as juveniles, consider 40-50 gallons per fish as adults.

Maximum Size

14 inches

Minimum Tank Size

300 gallons (school of six)

Tank Setup

Lots of swimming space and open areas. Avoid pointy obstacles as balas are easily startled and may injure themselves.

Tank Mates

Other large, peaceful fish.

8. Tinfoil Barb

This is another beautiful fish you can buy as a small juvenile and watch grow into a monster. Tinfoil barbs grow to over a foot. Like the bala shark, it is a schooling fish that should be kept in a group. They are docile but active and you will need a very large tank for a school of adults. When choosing tank mates for tinfoil barbs and bala sharks, consider other large, peaceful fish. Be careful stocking them with smaller fish. Remember one of the important rules of thumb in fish keeping: Big fish eat little fish. While tinfoil barbs are peaceful, they are often labeled as semi-aggressive fish because they may take advantage of an easy meal.

Maximum Size

14 inches

Minimum Tank Size

300 gallons (school of six)

Tank Setup

Plenty of swimming space. Live plants, river rocks, driftwood.

Tank Mates

Other large, peaceful schooling fish.

9. Iridescent Shark Catfish

The iridescent shark catfish is not a shark at all but a catfish—a catfish that grows bigger than some sharks. These guys can reach a maximum length of four feet. What size tank do you keep a four-foot fish in? You don’t. Fish this ridiculously large have no place in the aquarium trade. The only reasonable place to house them as adults is in a pond or a professionally managed aquarium. Yet you can buy them as small juveniles in many pet stores. The fish store probably won’t ask if you know anything about them, and they won’t inquire about what size tank you intend to put them in. Why do they even sell them if they know they aren’t appropriate for most fish keepers? We’ll get to that soon.

Maximum Size

48 inches

Minimum Tank Size

Pond or professionally managed aquarium

Tank Setup

River rocks, driftwood, live plants.

Tank Mates

Very large fish it can't eat.

10. Goldfish

Last on our list are the humble goldfish, the shiny little pets that often live in bowls. They are cold-water fish, and they pollute water rapidly. That means it’s not a good idea to keep them with tropical fish. There are a few different kinds of goldfish, and they all get bigger than many people think. Fancy goldfish grow to around eight inches long and require a 20-gallon tank for single fish with an additional 8-10 gallons for every fish after the first. Common and comet goldfish can top out at over a foot. You can keep them in a home aquarium by following the same rules as fancy goldfish, but eventually you will need to move them into a pond.

Maximum Size

8 inches fancy; 18 inches comet and common

Minimum Tank Size

20+ gallons for fancy, pond for comet and common

Tank Setup

Lots of swimming space. Cold-water setup (not tropical). Consider over-filtering.

Tank Mates

Other goldfish.

Which Fish Are Best for Your Home Aquarium?

As you can see, there are many large fish for freshwater aquariums commonly available in pet stores. Some of them, like angelfish, make good fish for community settings. Others, like the iridescent shark catfish, probably ought to be given a pass.

You can keep any of these fish in smaller tanks as juveniles. Just be sure you understand their care requirements as they age and be sure you can get them into a bigger tank or pond when the time comes. There is nothing wrong with having a huge fish tank in your home either. If you have the space and time for a 300-gallon tank, go for it.

Most fish keepers have tanks in the 10 to 75-gallon range. Pet stores must know this, right? So why do they sell so many fish that are inappropriate for the vast majority of aquarium enthusiasts?

Because people continue to buy them. If nobody bought bala sharks or tinfoil barbs, pet stores would not stock them. Unfortunately, there is an endless cycle of people who don’t know any better purchasing fish that have no business in their tanks

I did it when I first started keeping fish. Maybe you’ve done it too. We all make mistakes. The only way to break the cycle is to do the research and only purchase fish you can care for, not just today but for their entire lives.

This article is accurate and true to the best of the author’s knowledge. It is not meant to substitute for diagnosis, prognosis, treatment, prescription, or formal and individualized advice from a veterinary medical professional. Animals exhibiting signs and symptoms of distress should be seen by a veterinarian immediately.

Comments

Abhinav on August 27, 2020:

Did you forget wolfish? Wolfish are awesome big fish.I have never kept them but I have seen videos on them.

Eric Dockett (author) from USA on February 21, 2020:

@Chad - Yes, every angelfish behaves a little differently, just like bettas and oscars. That is true of most fish species, even tetras. I think people like to imagine they have personalities but really the fish are just reacting to stimulus and exhibiting learned behaviors. Some may behave differently than others and some may be a little smarter, in fishy terms. But, they are always going to act within a behavioral range that's governed by their instinct and evolution, not personality quirks.

Chad Carson on February 20, 2020:

What are your thoughts on an angelfish? Do they have a unique personality like Bettas or Oscars or are they kinda dumb like tetras?

Eric Dockett (author) from USA on February 12, 2020:

Thanks Rebecca!

Rebecca Mealey from Northeastern Georgia, USA on February 11, 2020:

What a nice article for fish as pets! I love the layout. Very helpful!