Green Terror Cichlids: Size, Tank Mates & General Care

As part of the Cichlid family, these fish are known for their metallic green and blue markings and inquisitive nature.

But with their reputation for aggressive behavior, it’s essential to understand their care requirements before bringing them home.

This article will provide all the information you need to keep your Green Terror Cichlids happy and healthy.

In this article, we’ve covered you, from tank size and water parameters to compatible tank mates and breeding tips.

Whether you’re an experienced fish keeper or just starting, our mission is to help you fulfill your thirst for knowledge and to ensure your success when caring for these incredible creatures.

Species characteristics and natural habitat

The Green Terror (Aequidens rivulatus) is a beautiful freshwater fish from the cichlid family.

It is sometimes mistakenly identified as related to two other species – Andinoacara salzberg and Andinoacara blombergi, – because they all share similar characteristics, such as narrow white edging.

However, the Green Terror has unique features that set it apart. Its vivid coloring distinguishes it, making it stand out in any aquarium.

In the past, it has been difficult to differentiate between A. rivulatus and its close relatives due to their similarities.

But with careful observation, it is now possible to tell them apart.

The Green Terror is a captivating fish that will bring life and color to any tank.

Its beauty and vibrancy will add a touch of uniqueness to your aquatic environment.

The Green Terror Cichlid is native to South America, being found in the coastal slopes of the Pacific Ocean from the Esmeralda River in Ecuador to the Thumbes River in Peru.

They inhabit tropical freshwaters such as rivers and streams, away from the brackish waters of estuaries and river mouths.

They have sandy substrates to burrow themselves into for shade and cover.



Their stunning metallic green scales are highlighted by bright blue markings on their face and body, with vibrant orange stripes on the dorsal and tail fins.

While the color patterns of male Green Terror Cichlids tend to be more pronounced, female fish can be a bit duller and lack the orange stripes.

Even juvenile fish are eye-catching, with a silvery-blue hue that deepens to the classic metallic green as they age.

Their ray-finned fins are supported by thin spines, particularly on their expansive dorsal fin.

Another way to distinguish between males and females is that males have a distinctive hump on their forehead composed of fatty tissue.

This hump tends to be bigger during the breeding season in the wild but can remain large for the lifetime of captive fish.

Green Terror Cichlids make an exciting addition to any aquarium due to their striking appearance and unique behaviors during the breeding season.


If you want a fish that will grow impressively large and require a spacious aquarium, then the Green Terror Cichlid might be for you.

These freshwater fish have an average size of 8 inches but can reach up to 12 inches in the wild.

It’s important to keep their growth rate in mind when choosing tank mates and the appropriate size.

Some aquarium owners have managed to get their fish to exceed 10 inches in size, even in their homes.

These factors will help ensure your Green Terror Cichlids have plenty of room to swim around and thrive without overcrowding or stunting their growth.


You need to be prepared for the long haul when buying fish, and it’s best to buy from a reliable breeder or store.

With an average lifespan of 7-10 years in captivity.

How long they live is determined by how well you care for them.

Maintaining good water conditions is key in ensuring your fish live long, happy lives.

But don’t make it complicated. Just follow the instructions in this guide and give your fish the best possible care.

By being dedicated to your fish and providing them with the best care, you’ll be rewarded with a companion that will stay with you long.

Basic Care Guidelines

When caring for Green Terror Cichlids, some important guidelines exist.

First and foremost, ensuring they have enough space in their tank is crucial.

Additionally, setting up the tank with proper decor and providing optimal water parameters will help keep these fish healthy and happy.

Finally, staying vigilant about potential diseases and regularly checking water parameters can prevent common ailments in your Green Terror Cichlids.

Tank Size Requirements

To ensure your freshwater Green Terror Cichlids are happy and healthy, providing them with a tank of at least 50 gallons is crucial.

This will give them enough space to swim around comfortably and reduce the chances of aggressive behavior toward other fish in the tank.

Having 35 gallons of space for each additional fish is recommended if you keep more than one.

When setting up your Green Terror Cichlid’s tank, incorporate ideal filtration to keep ammonia and nitrate levels low due to their large size and significant waste production.

Additionally, managing aggressive behavior is important when selecting tank mates.

Alternative tank options include adding natural barriers such as large rocks and driftwood or using floating vegetation as shelter.

These can also act as decoration ideas while providing safety for your fish.

Tank Setup Recommendations

Aquarium decor is essential to provide hiding places and natural barriers that mimic their natural habitat.

Here are some recommendations:

  1. Substrate options: A sandy substrate is preferred as it helps simulate their natural environment and prevents injury to their delicate barbels.
  2. Lighting choices: Green Terror Cichlids prefer lower light levels, so it’s recommended to use soft lighting or dimmers to create a more subdued atmosphere.
  3. Filtration systems: Powerful filters are necessary as these fish produce significant waste, and high ammonia and nitrate levels can cause health problems.

In addition to these suggestions, floating vegetation such as Java ferns and Anubias can help prevent plant uprooting while providing cover for juvenile fish.

Ensure all the roots are properly protected with pots to prevent harm because these fish have a reputation for uprooting and consuming vegetation.

Large rocks and driftwood can also act as natural barriers in the aquarium while serving as decorative elements that enhance the overall aesthetic of the tank.

Remember that these fish are curious creatures who love to explore every corner of their home, so it’s important to provide ample space for swimming and enough hiding spots for when they need some privacy.

Water Parameters

Maintaining optimal water parameters is crucial for the health and well-being of your beloved Green Terror Cichlids, so it’s essential to monitor pH levels, water hardness, and temperature regularly.

Water parameter testing should be conducted at least once a week to ensure the levels are within the recommended range.

It’s important to note that sudden changes in pH levels can cause stress for these fish and lead to health problems.

Therefore, pH level maintenance should gradually be done by adding small buffers or adjusting the water source.

Filtration systems are also critical for keeping the water clean and free from harmful toxins.

A powerful filter should be used to keep ammonia and nitrate levels low due to their large size and significant waste production.

It’s important to keep your water in the right conditions.

The ideal temperature is between 72 and 77 degrees Fahrenheit, while you should keep the water temperature between 68 and 80 degrees.

Ensure the pH levels are between 6.5 and 8.0, and the water hardness should be 5 to 20 dGH.

Furthermore, regular water changes are necessary to maintain optimal conditions as Green Terror Cichlids produce a lot of waste.

Changing 20 to 25% of the tank volume every week is recommended depending on how many fish you have in your aquarium.

By maintaining good filtration systems, conducting regular water changes, and maintaining pH levels, your Green Terror Cichlids will thrive in a healthy environment.

Common Diseases

It’s important to be aware of common illnesses that can affect your fish, so you can quickly spot any signs of disease and take action to treat them.

Green Terror Cichlids are prone to all major freshwater ailments, including parasitic infections and skin conditions.

Keeping them healthy is crucial to implement preventative measures such as regular water changes and monitoring water parameters.

If you notice signs of illness in your Green Terror Cichlid, several treatment options are available.

These include medicated dips or baths, antibiotic treatments, and quarantine tanks for infected fish.

It’s worth noting that fish immunity is not as strong as other animals, so prompt treatment is necessary for the best chance of recovery.

Some common diseases are:

  • Head and Lateral Line Erosion, often called Hole-In-Head Disease, is a condition you should be aware of. It can cause serious damage if left untreated.
  • Lymphocystis disease – white lesions can be seen on the body, fins, or even the mouth and gills. Don’t mistake it for Ich, though, as this is a virus that affects the connective tissue.

By staying vigilant about your fish’s health and seeking proper treatment, you can give your Green Terror Cichlid a long and happy life in your aquarium.

Diet and Feeding

To keep your beautiful Green Terror Cichlids healthy and happy, you must pay close attention to their diet and feeding habits.

These fish have a voracious appetite, but overfeeding can lead to serious digestive problems.

It’s important to feed them twice a day and only enough food that they can eat in a couple of minutes.

Green Terror Cichlids thrive on a varied diet of flakes and live food.

Feeding frequency should be monitored closely, as they tend to eat more than they need when presented with too much food.

Live food such as brine shrimp or bloodworms are great supplements for their diet but should not be the sole source of nutrition.

Keeping up with their dietary needs will help prevent digestive problems and promote optimal growth and behavior from these stunning fish!

Behavior and Temperament


It’s important to know that they can be prone to aggressive behaviors and exhibit inquisitive behavior as they explore every inch of the tank.

Aggression management is crucial for keeping Green Terror Cichlids with other fish species.

They can become territorial and sometimes attack other fish if they feel threatened or stressed.

Keeping a bonded pair together in a large enough tank is recommended to prevent aggression toward other fish.

Despite their aggressive tendencies, Green Terror Cichlids have interesting social behavior and exploring tendencies that make them fascinating pets.

They are known for being highly curious and will often investigate every nook and cranny of their environment, and this makes them great fun to watch as they interact with their surroundings.

Providing plenty of hiding places, such as rocks, caves, and driftwood, will help reduce stress levels while allowing them space to explore freely.

Compatible Tank Mates

Tank mate selection is crucial for Green Terror Cichlids since they’re known to be aggressive and territorial.

It is essential to be thoughtful when selecting tank mates that will get along to protect against aggression.

Community options include similar-sized fish, such as Cichlids or catfish, that aren’t seen as food.

Keeping a bonded pair together is also recommended since they can become more aggressive toward others during breeding.

Compatible schooling fish, such as Silver Dollars, can also be added as long as they aren’t too small or timid.

However, it’s essential to closely monitor the Green Terror Cichlid’s behavior towards these fish and remove any showing signs of aggression.

Adding hiding spots like caves and rocks can help reduce territorial conflicts and provide a sense of security for all tank inhabitants.

Overall, with proper tank mate selection and careful monitoring, Green Terror Cichlids can coexist peacefully with other fish in a community aquarium setting.

Breeding Tips

When breeding your beautiful Green Terror Cichlids, it’s important to know the triggers that can initiate the process.

Raising the water temperature or feeding live food frequently can help stimulate breeding behavior in these fish.

Once they lay their eggs on a flat rock or directly onto the glass, males defend their breeding site while females protect their young.

It’s essential to provide a safe and secure environment for your cichlids during this time to ensure the successful hatching of the eggs.

Green Terror Cichlids are known for being prolific breeders, with bonded pairs able to breed very frequently if water conditions are optimal.

Females can lay upwards of 600 eggs at once, and parental behavior is highly protective of their young.

Fry care involves feeding them microplankton, infusoria, and baby brine shrimp until they’re fully grown enough to eat regular food.

Separating the fry from the parents is unnecessary with Green Terror Cichlids since males and females take an active role in caring for them as they grow up.


In conclusion, Green Terror Cichlids are fascinating fish that require specific care to thrive in your aquarium.

These fish can be aggressive, so choosing tank mates wisely and avoiding overcrowding is important.

When it comes to feeding, Green Terrors are not picky eaters, but it’s essential to offer them a varied diet that includes high-quality pellets and frozen or live food.

Finally, breeding these fish requires patience and careful attention to water conditions.

Overall, taking care of Green Terror Cichlids can be challenging but rewarding for any aquarist who appreciates their unique beauty and personality.

Your Green Terrors will thrive in your aquarium with proper care and attention for many years.