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6 Great Tank Mates for Fire Eels (Compatibility Guide 2023)

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By Lindsey Stanton

Fire Eel in aquarium

While a Fire Eel is an excellent fish on its own, having a single fish in a tank can get a bit boring. But what tank mates can you add to their enclosure that won’t cause any problems—or end up as lunch?

We broke down the six best options here and when you might want each one.

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The 6 Tank Mates for Fire Eels

1. Angelfish (Pterophyllum) — Easiest to Care For

Angelfish in aqurium
Image Credit: Piqsels
Size 6” long and 8” high
Diet Tropical flakes, color flakes, tropical granules, and shrimp pellets
Minimum tank size 20 gallons
Care Level Low
Temperament Peaceful and timid

One of the best tank mates that you can get for your Fire Eel is an Angelfish. Angelfish have a typically peaceful and timid temperament, and their larger size means the Fire Eel will not see them as food.

Keep in mind that Angelfish do best in schools, so you should consider getting at least six. Otherwise, they can get a bit temperamental and territorial.

Finally, since Angelfish don’t require an overly large enclosure, the tank you have for your Fire Eel is likely already large enough.

2. Barb Fish (Barbus Barbus) — Most Variety

tinfoil barb fish
Image Credit: Zeyd Ladha, Pixabay
Size 3” to 13”
Diet Tropical flakes, color flakes, tropical granules, and shrimp pellets
Minimum tank size 30 gallons
Care Level Low
Temperament Playful but occasionally aggressive

Barb fish come in many different varieties, which is part of the appeal of adding them as tank mates. However, finding the perfect barb fish for your Fire Eel requires a bit of homework.

Too small of a fish and your Fire Eel will eat it, and too large of a fish and you’ll need to massively upgrade your tank size. These fish are known to be extremely playful but can have an occasional aggressive streak.

This usually isn’t a problem with a Fire Eel companion, but it’s something to keep in mind if you’re adding other fish into the fray.

3. Silver Arowana (Osteoglossum Bicirrhosum) — Most Challenging Tank Mate

silver arowana in aquarium
Image Credit: Grigvovan, Shutterstock
Size 47”
Diet Earthworms, crab, crickets, shrimp, beef heart, krill, crustaceans, and feeder fish
Minimum tank size 250 gallons
Care Level High
Temperament Highly aggressive

Sometimes, you want a bit of a challenge, and when you do, the Silver Arowana is an excellent choice to pair with your Fire Eel. These massive fish can grow up to 4 feet long, and they require a tank of at least 250 gallons!

They’re also extremely aggressive, so you can’t pair them with any smaller fish. If you’re thinking of adding a Silver Arowana to your tank, ensure that you have enough space and can keep conditions and feedings ideal—otherwise, you might run into problems.

Related Read: 10 Best Tank Mates for Arowanas

4. Oscar Fish (Astronotus Ocellatus)

white and orange oscar fish
Image Credit: Fabika, Shutterstock
Size 11″ to 12”
Diet Tropical flakes, color flakes, shrimp pellets, bloodworms, shrimp, boiled peas, and blanched spinach
Minimum tank size 55 gallons
Care Level Medium
Temperament Aggressive and territorial

A slightly challenging but highly popular fish to pair with your Fire Eel is the Oscar Fish. Just keep in mind that Oscar Fish are incredibly territorial, even with other Oscar Fish.

So, while a 55-gallon tank might be the minimum size, you might run into problems if you use anything smaller than 75 gallons. The more Oscar Fish you add, the larger tank that you need. Otherwise, they’ll fight and kill each other.

5. Green Terror (Andinoacara Rivulatus)

green terror cichlids
Image Credit: Piqsels
Size 8”
Diet Frozen krill, bloodworms, and brine shrimp; tropical flakes, plankton, green vegetables, cichlid pellets, or live red earthworms
Minimum tank size 75 gallons
Care Level Medium
Temperament Aggressive and territorial

An aggressive and territorial fish that pairs well with the Fire Eel is the Green Terror. Green Terrors can add a splash of bright color to your tank.

Due to this fish’s territorial nature, you need to ensure that you have a large enough tank, with a 75-gallon tank being a good starting point. The more fish that you add, the larger the tank that you’ll need.

6. Bichir Fish (Polypteridae)

Banded Bichir Fish
Image Credit: chonlasub woravichan, Shutterstock
Size 12” to 30”
Diet Shrimp, mussels, silversides, worms, and other live food
Minimum tank size 55 gallons
Care Level Medium
Temperament Occasionally aggressive

The Bichir Fish is an option that you need to do your research on before purchasing. Some Bichir Fish only reach 12 inches, which means they’re a great addition to a smaller tank.

However, they can reach 2.5 feet in length, so if you get a larger Bichir Fish, you might need closer to a 100- or 150-gallon tank to fit both them and a Fire Eel!

Finally, keep in mind that Bichir Fish are mostly nocturnal, so you likely will not see them move around much during the day.

What Makes a Good Tank Mate for Fire Eel?

By far, the most crucial factor when looking for a tank mate for your Fire Eel is the size of the potential tank mate. Fire Eels are predators by nature, so you don’t want to pair them with smaller fish.

However, Fire Eels don’t mess with fish that are larger than them, which means you don’t need to worry about them getting aggressive toward a large fish.

It also means you can pair them with slightly more aggressive fish. Since the Fire Eel will leave them alone, the chances of them fighting with each other are relatively low.

Fire Eel open mouth
Image Credit: Contentus, Shutterstock

Where Do Fire Eels Prefer to Live in the Aquarium?

Fire Eels are bottom feeders through and through, and as such, they spend most of their time at the bottom of the aquarium.

They will search the bottom of the aquarium for food and actually burrow their way under the substrate throughout the day. This means they’ll often escape the notice of larger or more territorial fish.

This makes it a bit easier to find them a tank mate that they don’t want to eat and that doesn’t want to eat them.

Water Parameters

Caring for a Fire Eel is relatively easy. They’re freshwater fish that need the temperature kept between 75 and 82 degrees Fahrenheit.

They’re extremely sensitive to different temperatures, though, so you need a thermostat and, potentially, a water heater to help you regulate the tank.

These easy parameters mean you can add plenty of other tank mates to the aquarium and focus some of the finer details around their needs because it won’t affect your Fire Eel.


The average Fire Eel will reach 3.3 feet in length, which is no joke for an aquarium fish! Therefore, you need a minimum tank size of 80 gallons to accommodate this beautiful fish.

Keep in mind that if you’re adding more fish, you’ll need to get an even larger tank, which can quickly drive up your costs.

Aggressive Behaviors

Most Fire Eels are extremely docile unless you put them around their own kind. If you house more than one Fire Eel together, you need to have plenty of space and plenty of places to hide; otherwise, you’re asking for trouble.

Fire Eels also appreciate tons of places to hide if you’re adding other types of fish. This can be as simple as a loose substrate that they can burrow under or different objects inside the tank.

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2 Benefits of Having Tank Mates for Fire Eel in Your Aquarium

Adds more variety to the tank

While Fire Eels are interesting enough by themselves since you can’t house them with their own kind, not having tank mates means having only one fish in the aquarium.

Since these Eels sleep throughout most of the day, that means when you look at the tank, you probably won’t see much happening! Adding a tank mate changes the scenery and spices things up.

It gives them a more natural habitat

In the wild, Fire Eels aren’t the only fish around, so if you’re looking to replicate their natural habitat (and you should!), then you should add different types of fish.

Just ensure that you don’t overcrowd the tank, as this won’t replicate their natural habitat either.

Picking a Substrate for a Fire Eel

Fire Eels love to burrow, which means you need to account for two things. First, the substrate needs to be something that they can burrow into. Second, you need to avoid plants that grow into the substrate.

Ideally, you want about 2 to 3 inches of a fine sand that won’t irritate your Fire Eel. If you want live plants, you need ones that float. Otherwise, your Fire Eel will quickly destroy anything that you plant.

To avoid learning an expensive lesson, be aware that live plants that grow in the substrate and Fire Eels simply aren’t a good mix.

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The good news is that if your Fire Eel has a large aquarium, there’s no reason that you can’t add a tank mate, and you have plenty of choices. Just ensure that the new tank mate won’t attack your Fire Eel and that they’re not small enough for your Fire Eel to eat!

If you hit both objectives, your Fire Eel will likely just ignore their new companion, which means you get another fish without the headache or price tag of a new tank!

See Also: 9 Best Tank Mates for Peacock Eel

Featured Image Credit: Roberto Dani, Shutterstock

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