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Emperor Tetra Care Guide: Everything You Need To Know

Emperor Tetra Care Guide: Everything You Need To Know

The Emperor Tetra is a freshwater fish that is often overlooked. For me, I think they are a stunning fish, a hidden gem. Not only are they visually stunning, but these tetras also exhibit a calm and peaceful demeanor, making them perfect companions for community tanks.

With their vibrant colors, peaceful nature, and easy-to-maintain care requirements, these fish are an ideal choice for both novice and experienced fish keepers. 

Before bringing home your Emperor Tetras, it’s important to consider their preferred water conditions, feeding habits, and suitable tank mates to ensure their well-being and happiness. Let’s explore in detail everything you need to know about Emperor Tetras.

Emperor Tetra Overview and Natural Habitat

  • Common name: Emperor Tetra
  • Scientific name: Nematobrycon palmeri
  • Care level: Easy
  • Size: 1.65 inches (4.2 cm)
  • Lifespan: Six years
  • Temperament: Peaceful
  • Diet: Omnivore
  • Group size: Six or more
  • Minimum tank size: 10 gallons
  • Tank level: Mid-top dweller
  • Water temperature: 73°-81°F (23°-27°C)
  • Water pH levels: 5.5-7.5
  • Water hardness: 3 to 8 dGH

Emperor Tetras, (also known as Nematobrycon palmeri) are a small, freshwater species. They’re popular in community tanks for their friendly personalities and form schools of six or more. Like many other tetras, these tropical fish are easy to care for.

These tetras have a natural habitat in western Colombia, most commonly found in San Juan and Atrato river basins, consisting of clear, slow-moving water. They were first discovered by William A. Kyburz, a fish exporter based in Colombia. He started exporting them to the U.S. in 1960, where the fish gained popularity as a pet.

The species has changed very little since then, despite breeding in captivity. They still look very similar to their wild counterparts today.

Emperor Tetra Appearance and Size

The Emperor Tetra is a beautiful fish characterized by a long and slender body shape. Its primary color is a captivating bluish-gray, which is complemented by the unique iridescent quality of its scales. In low-light conditions, the scales reveal enchanting purple undertones, creating a captivating sheen.

One of its most distinctive features is a prominent black stripe that extends from its mouth all the way to the tip of its tail. The fins of the Emperor Tetra have subtle yet eye-catching details, with hints of yellow in the anal and dorsal fins. These fins may also display a touch of red at the base where they meet the body, along with a black outline along the edges.

These gorgeous little fish aren’t very large, usually reaching 1.65 inches (4.2 cm) as adults. However, some can grow up to two inches (5 cm). 

Difference Between Males and Females

It’s easier to tell the difference between Emperor males and females than you might think. They’re one of the more sexually dimorphic tetras.

The males have a trident tail and metallic blue eyes, while the females have metallic green eyes. Males have pointier fins than females as well. 

The females are usually slightly rounder and larger, while the males are smaller and straighter.

Emperor Tetra Personality and Behavior

Emperor Tetras are known for their peaceful and sociable nature, making them ideal for community aquariums. They are active and appreciate having lots of space to explore and zip around the tank.

They thrive in well-planted tanks that mimic their natural habitat, providing hiding places and areas for them to hide when needed. These fish are also known for their shoaling behavior, meaning they prefer to be kept in groups of at least six or more. This helps them feel secure and reduces stress levels.

While Emperor Tetras are generally peaceful, it’s important to note that males can occasionally display minor territorial disputes or fin-nipping behavior, particularly during breeding periods. However, these conflicts are typically short-lived and do not escalate to the point of causing significant harm.

Emperor Tetra Expected Lifespan

Emperor Tetras have an average lifespan of up to six years, provided they receive proper care and attention throughout their lives.

You’ll want to provide a well-maintained environment with ideal water parameters, balanced nutrition, and a stress-free atmosphere. Additionally, regular water changes, proper filtration, and diligent monitoring of their overall health are also essential to ensure these little guys live a long and happy life.

Emperor Tetra Care and Tank Set Up 

Knowing what water conditions and tank setups these tetras are like will help you keep them healthy. Choosing the right size tank and using their preferred water parameters are essential. You’ll also need to ensure you set the tank up with lots of decors for the tetras to hide in.

Tank Size

Depending on a few factors, you can choose between a 10 or 20-gallon tank. If you have a few bonded pairs or a small school, they can fit in a smaller 10-gallon. However, if you have an entire school of Emperor Tetras, you’ll need to use a 20-gallon tank.

You’ll also need to choose a 20-gallon for when you want to keep a community tank. With this setup, you can have a school of tetras and other fish without overcrowding.

In a 20-gallon, it’s also best to have four or five females with one male Emperor. This setup is good for reducing aggression between your tetras. Your tank will be much more peaceful since you won’t have to worry about the males butting heads with each other.

How Many Emperor Tetras Are Suitable For 20 Gallons?

Emperor Tetras need open water to swim in, so it’s better to size up whenever possible and give them enough room to move freely. For this reason, 20 gallons will almost always be a better choice than 10.

Six to eleven Emperor Tetras are suitable for 20-gallon tanks. This amount is enough for them to form one to two schools comfortably. They’ll become stressed and sick quickly if their school isn’t large enough. You must also check that more females are in the tank than males.

Water Parameters

  • Water temperature: 73°-81°F (23°-27°C)
  • Water pH levels: 5.5-7.5
  • Water hardness: 3 to 8 dGH

These fish come from clear, slow-moving water, so you’ll want to replicate those conditions as closely as possible. It’s also best to keep their water as consistent as possible since sudden changes can cause stress. 

Luckily, achieving optimal tank conditions for Emperor Tetras is pretty straightforward. 

Water Temperature 

Emperor Tetras are tropical freshwater fish, so they need to live in warm conditions. They like water between 73°-81°F (23°-27°C), but you want to try to keep their tank in about the middle of that range. So, 77°F (25°C) is best.

I recommend using a water heater unless you live somewhere very warm. Sudden temperature drops can be disastrous to tetras, making keeping the water temperature stable essential.

Water pH Levels

These fish have a preference for water with a pH ranging from 5.5 to 7.5, leaning towards a slightly acidic to neutral environment. 

Like many other tetras, they tend to thrive in more acidic water. So try to maintain a pH level towards the lower end of that range.

Water Hardness

Emperor Tetras live in moderately hard water, meaning some minerals are in it. You’ll want to keep it between 3 and 8 dKH

It’s important to note that this differs from other tetra species, which like soft water better. You must be careful if you combine them in a community tank.

Water Current

Lastly, these tetras are like slow-moving currents since it reminds them of home. They come from slow, gentle rivers, so you don’t want to subject them to heavy flowing water. Depending on your filter, it’s usually enough to gently stir the water.

Too much current will upset your Emperors, so you’ll want to watch how they react to the flow you add to the tank. If they avoid the moving water entirely or get pushed around too much, you’ll need to remove it.

Generally, these tetras will prefer no current compared to too much. So don’t hesitate to remove it.

What To Put in the Tank

Emperor Tetras love lots of hiding places, as they can become stressed without them. Providing ample hiding spots, such as plants, rocks, or driftwood, will ensure their comfort and well-being. 

I also recommend providing them with a tank environment that has dim lighting, to help replicate their natural habitat and overall happiness.


Sand, fine gravel, and pebbles are all good substrate options for Emperor Tetras as they don’t typically explore the tank’s bottom extensively. Sand is generally considered the most suitable, as it minimizes the risk of them choking on it.

Darker substrates are also best because they more closely resemble the substrate from these tetra’s natural habitat. Plus, sand tends to look the most natural out of these options.


You’ll want to provide plenty of hiding spaces for your Emperors. They enjoy zipping around their tank but need spaces to return to if startled. Tanks with many plants are best because they keep out light and make the tetras feel more secure.

You can add many rocks, pieces of driftwood, and other decorations to the tank. A good tip is to place your decorations in groups of three towards the sides and back of the tank so there’s open water in the front-middle section.

Arranging your tank like this leaves some open waters for the tetras to dart through when excited. 

Ideal Plants

Plants will serve as hiding places when your fish feel stressed and need a place to retreat to.

Live plants are always an excellent choice for a fish tank. Don’t worry; if you’re a beginner, these plants are still easy to grow.

Java fern and water sprite are great for Emperor Tetras because they have a lot of floating leaves that block light and make for good hiding spots. Frogbit, Jungle Vallisneria, and Amazon swords are some more excellent options.

These plants are straightforward to care for, and your fish will surely appreciate having them.

Make sure you distribute the plants evenly throughout the tank, ensuring your tetras have sufficient room to swim around freely.


These tetras don’t need a lot of light. In fact, they hate bright light.

Most of the time, just the light from your room will be enough for them. Although, you can connect a very dim light to their tank if you prefer. 


Generally, you will want to include a heater for tetras. These tropical fish need to live in water that’s probably warmer than your home. 

The AQQA Submersible Aquarium Heater is a good option. It’s easy to set up and lets you customize the temperature for the tank. It stops when it gets too hot and starts when the tank drops a single degree, so the water temperature is always consistent for the fish.

While Emperor Tetras are pretty hardy fish, they can be very susceptible to sudden changes in water temperature. So, you’ll want to take care in picking and installing their water heater.


If you have a smaller planted tank, the plants can likely handle much of the bioload from a school of Emperors. You usually only need a hang-on filter for small tetras like these.

However, you need to check that the filter won’t create too much water disturbance. A light current is good, but it shouldn’t push your fish.

Emperor Tetra Tank Mates

Emperor Tetras are peaceful and can get along with many other species. The males are slightly more aggressive but won’t bother other fish unless too many are in the tank.

Any other peaceful species that isn’t larger than the Emperor Tetras will get along fine with them. Anything too big or aggressive will bully the tetras and might even try to eat them! So please ensure you’re only adding non-aggressive fish to the community tank.

Some great Emperor Tetra tank mates include:

Tank Mates To Avoid

As mentioned above, you don’t want to keep Emperor Tetras with aggressive fish. Due to their small size and calm personality, Emperors can easily be tormented by larger fish.

You should avoid bettas and angelfish since they’re too aggressive. You should also not add small shrimp to the tank because they can become a snack for the tetras.

Emperor Tetra Food and Diet

The Emperor Tetras are omnivores but aren’t too picky when it comes to food. They’ll eat pretty much anything, but make sure to give them small-sized bites because their mouths are tiny. 

For their regular meals, good-quality fish flakes and pellets will do the trick. If you want to treat them, you can add some bloodworms, baby brine shrimp, or mosquito larvae every now and then. These foods have higher amounts of protein, making them suitable for conditioning your fish for breeding.

Breeding Emperor Tetras

If you take good care of your Emperors, they’ll often breed in their main tank without issues. However, you’ll want to use a separate tank if you plan on keeping the fry because adult tetras will eat the eggs.

Your breeding tank should have the following conditions to encourage spawning:

  • 80 to 82°F (26 to 27.8°C)
  • Lots of plants
  • A pH level of 7.0
  • A sponge filter

Then, once you’re ready for the fish to breed, identify the bonded pairs in your tank. Feed the fish more live food and wait for the female to start getting rounder. Once she does, move the bonded pair to your separate breeding tank.

Breeding usually happens within 24 hours if the tank’s conditions are right.

Emperor Tetras Common Health Issues

Emperor Tetras have many of the same health issues as other fish. If they get too stressed, their immune system weakens, leaving them vulnerable to bacterial and fungal infections. Keeping their tank clean can significantly reduce the spread of disease.

Knowing more about these health issues can help you prevent them.

Gill Flukes

Dactylogyrus, or gill flukes, are parasites that attack the gills of Emperor Tetras. They’re incredibly harmful and can destroy a tetra’s gills if you don’t treat them.

Gill Flukes Symptoms

Fish that are infected with this parasite will have swollen, pale gills. They also increase mucus production, so they’ll look slimy. Infected tetras will gasp, lose their appetite, and become erratic.

They may even try to jump out of the tank due to stress.

Gill Flukes Treatment

You can treat gill flukes with antibacterial medications. Although, products that have Praziquantel are the most effective at eradicating the parasite.

You’ll want to separate infected fish and keep them in small quarantine tanks. Then, apply the treatment according to the given instructions.

Gill Flukes Prevention

Gill flukes attack fish that are stressed and in poor living conditions. Keeping their water clean and clear will help prevent them.

Flukes can also appear when species of fish that shouldn’t be kept together are in the same tank.


Ich (white spot disease) is a widespread disease among all pet fish species, and it’s prevalent in tetras too. It’s another parasitic disease, but it’s easy to identify and treat.

Ich Symptoms

Ich is easy to see on the tetra’s body. It appears as small white spots that look like salt, usually on the body and gills of the fish. 

If your Emperor is infected, it will usually lose its appetite, hide, and try to scratch itself on items in the tank.

Ich Treatment

Plenty of treatments for ich are readily available online and in pet shops. You’ll need to ensure that you follow the instructions on the medication for the best results. 

Ich can spread quickly, so you’ll need to act fast. It’s a good idea to start by raising the tank’s temperature by one to two degrees and adding aquarium salt to reduce the lifespan of the parasite. Then, give your fish the treatment.

Ich Prevention

Luckily, ich is easy enough to prevent. You’ll need to quarantine new fish in a separate tank for several weeks before adding them to your main one. 

Make sure to quarantine anything you plan on adding to the tank, even plants and other creatures like snails.

Are Emperor Tetras Right For You?

Emperor Tetras are right for anyone, including beginners. They’re easy to care for, hardy, and fun in any tank. Many people raise them first before trying to care for other fish to gain experience. You’re sure to enjoy watching them.

So, yes, Emperor Tetras are right for you. They go great in any tank and are easy to raise, whether or not you’ve kept fish before.

Emperor Tetra FAQs

Do Emperor Tetras Eat Shrimp?

Emperor Tetras will eat small shrimp and babies. They will try to eat them if they can swallow them. You’ll need to ensure that you only keep large adult shrimp with your tetras to prevent that from happening.

Shrimp can become stressed when kept with Emperors, so you’ll want to consider not including them.

How Many Emperor Tetras Can Live Together?

Emperor Tetras can live in groups of six or more fish. Any less than that, and they become very stressed. These prey fish live in large schools to protect themselves, so you’ll want many in a tank.

However, a bonded pair of Emperor Tetras can do just fine when their tank is in good condition.

Do Emperor Tetras Jump?

Emperor Tetras can jump, so you should always have a lid on your tank to prevent accidents. They usually do this when they feel stressed. You can avoid jumping by keeping your water in good condition.

Tetras may jump out of their tank if the water quality is terrible or they’re stressed from being bullied by other fish.

Wrapping Up

Caring for Emperor Tetras can be a rewarding experience and you’ll love them for their peaceful and sociable nature.

By providing them with a well-maintained aquarium, suitable tank mates, and a balanced diet, you can ensure the health and happiness of these vibrant little fish. Remember to closely monitor water parameters, maintain proper filtration, and perform regular water changes to create a stable and pristine environment. 

Additionally, keep in mind the importance of providing ample hiding spots and vegetation to mimic their natural habitat. If you decide to get Emperor Tetras for your tank, I’m sure you’ll love them.

I’m Elle, the founder of FishHQ. I created this website to share knowledge, tips, and inspiration for beginner hobbyists to help them create a healthy, happy, and vibrant environment for their fish to thrive. Read more...