July 26

Sarah Robertson

Bring Life to Your Aquarium with Koi Angelfish

Angelfish are one of the original species to be kept in captivity and they remain a popular choice among fish keepers. Because breeders have crossed different varieties of angelfish, there are now many colors available in stores. The natural color of these fish is silver with dark vertical stripes, but you can find them in black, gold, marble, and more. One popular hybrid is the Koi angelfish which features bright colors.

Koi angelfish are stunning, and if you're looking to liven up your aquarium with some color, they are a perfect choice. This strain of angelfish has been bred for its mottled black and white coloration. Some may have gold markings on the head. The young specimens may have a red hue beneath the eyes that fades with age. 

They are originated from South America and are found in the lakes, rivers and streams of Brazil, Peru and Colombia. They live in small groups or large schools near the surface of the water.

Koi angelfish prefer a warm tropical tank with plenty of plants to hide in. If you are a newbie to aquarium keeping, then Koi angelfish are a good fish for you to start with as they are relatively easy to care for. In this article we shall discuss how to properly care for Koi angelfish in the home aquarium.

Koi Angelfish Quick Care Guide

  • Scientific Name: Pterophyllum sp
  • Common Name: Koi Angelfish
  • Origin: Amazon and Orinoco River Basins, South America
  • Family: Cichlidae
  • Diet: Omnivore
  • Minimum Tank Size: 30 gallons
  • Temperature: Between 78° and 84° F
  • PH Range: 6.5 – 6.9
  • Lifespan: 10-15 years
  • Water Type: Hard
  • Breed Type: Egg Layer
  • Care Level: Easy- Moderate
  • Temperament: Semi-aggressive
  • PH Range: 6.5 – 6.9
  • Lifespan: 10-15 years
  • Water Type: Hard
  • Breed Type: Egg Layer
  • Care Level: Easy- Moderate
  • Temperament: Semi-aggressive
  • Aquarium Hardiness: Hardy
  • Max Size: 6 inches
  • Compatibility: Community Tanks
  • Aquarist Experience Level: Beginner

Koi Angelfish Size

Koi angelfish grow to be around 6-7 inches on average. They are a common aquarium fish species and need enough room to swim in the tank.

These fish can get tall, so you must provide them with adequate vertical space in the tank. There are many factors that play into how large your fish will grow, including water quality, diet, and also the size of the tank. Genetics also plays an important role in size determination.

Koi Angelfish Lifespan

Koi angelfish can live up to 10-15 years with proper care. However, many will not reach this age when kept in captivity due to improper care or unsuitable water parameters.

The key to keeping your Koi angelfish healthy and happy is providing them with the right tank setup and diet. Regular water changes and monitoring of water parameters are essential for keeping your Koi angelfish happy and healthy.

Koi Angelfish Behaviour

Koi angelfish are relatively peaceful fish and can easily be kept with other fish species. They usually live in small groups or large schools and swim near the surface of the water.

These fish love to graze on algae and will often pick at rocks, driftwood, and decorations for food. However, they can also eat smaller fish and shrimp, so it is important to make sure your tank is well-stocked with plants and plenty of hiding spots.

Koi angelfish may also display some aggression towards other fish or even their own kind. To prevent this, provide them plenty of hiding spots in the aquarium and don't overcrowd the tank.

When kept in a large enough tank with plenty of places to hide, Koi angelfish can make great additions to any community aquarium.

Koi Angelfish

Koi Angelfish Appearance

Angelfish come in many colors, but koi are especially beautiful and perfect for adding some life to your aquarium. This particular species of angelfish has been bred for its stark black and white colors. Some may have gold markings near the head. The younger fish may also display a red hue beneath their eyes, though this fades as they age.

These fish have a diamond-shaped body and can reach 6 inches in length and 8 inches or more in height. They have round, laterally compressed bodies, triangular dorsal fins, and anal fins. The dorsal fin has 10-11 spines and the caudal fin is deeply forked.

Like other angelfish, Koi have large eyes and a pointed head. They also have long Barbels which they use to find food in the substrate.

Koi Angelfish Tank Setup

Setting up a tank for Koi angelfish requires a bit of extra care. These fish need plenty of space to swim around as they can reach quite a large size. If you are a novice aquarium keeper, then read on for some tips on setting up the perfect tank for your Koi angelfish.

Tank Size

Koi angelfish require a minimum tank size of 30 gallons. You should also provide them with enough vertical space as they can reach heights up to 6 inches or more.

There are many benefits in having a larger tank size, such as better water quality, more space to swim around, and fewer issues with aggression.

Sometimes when these fish are provided with less space, they can become aggressive or stressed. Make sure to provide them with plenty of space and they will be much happier and healthier in the long run.

Water Parameters

Koi angelfish prefer slightly alkaline water with a pH range of 6.5 – 6.9 and a temperature between 78-84°F.

They also prefer soft to medium hard water with a hardness between 6-12 dGH. A quality filtration system is also necessary as these fish produce a lot of waste. The level of dissolved oxygen in the water should be kept high, as these fish are very active and require plenty of oxygen to survive.

Finally, regular partial water changes every 1-2 weeks are recommended to keep the tank clean and free from pollutants.

Tank Decor

A few things to keep in mind when decorating their tank: these fish need plenty of hiding spots. This can be achieved by using live plants, caves, and other decorations.

If you want to make your fish tank look and feel more like home for your fish, consider adding some live plants. Some good choices that are easy-to-care for and provide shelter for your fish include java fern, anubias, java moss, hornwort, and water sprite. Not to mention, they also help support the local ecosystem by filling the water with oxygen. If you don't want to use live plants, plastic ones can work just as well; though clean them regularly to prevent them from leaching toxins into the water.

Keep in mind that your fish like to swim at all depths of the tank, so you'll need decorations reaching from the bottom to the top. Some good picks are driftwood, rocks and caves. But beware using any decorations with sharp or jagged edges because they might hurt your fish.

Lastly, you need to select a substrate. A sandy substrate is the best option for a Koi Angelfish tank because their delicate fins won't get damaged as easily this way.

As for lighting, these fish do well in dimly-lit tanks. You can recreate this by using an aquarium hood with a low-wattage bulb or by placing floating plants around the tank to diffuse the light.

Tank Maintenance

Maintaining a Koi angelfish tank requires regular cleaning and monitoring of the water parameters. It's important to do weekly partial water changes to keep the water clean and free from pollutants. Always use a good quality aquarium vacuum to remove any waste or uneaten food in the substrate.

It is also recommended that you test your aquariums water parameters regularly. Doing so will help you to identify any potential problems before they become serious. Test your water for ammonia, nitrite, pH and other parameters with a good aquarium test kit.

Finally, the tank should be cleaned on a regular basis. This includes removing any algae or debris from the walls of the tank and cleaning the filter media.

Note: It's important to condition your water before adding it to the tank. Water conditioners help eliminate chlorine and other toxins that can be harmful to your fish. Make sure you're using a dechlorinator specifically made for aquariums!

Koi Angelfish Diet

Koi Angelfish are typically omnivores that consume small insects, crustaceans, and algae in the wild. As pets kept in aquariums their diet can be supplemented with:

  • Pellets and flakes are an easy way to provide your fish with a well-balanced diet. These products typically contain a variety of ingredients, including fish meal, plant matter, and vitamins.
  • In addition to pellets and flakes, you can give your Angelfish fresh foods like brine shrimp, frozen bloodworms, and blanched vegetables. While this is a great way to make sure they're getting the nutrients they need, don't overfeed them as it could create health problems down the road.
  • If you want to give your fish a diverse diet, frozen food is a great option. Sometimes it can be tricky to get fresh seafood, so having frozen options available is ideal.
  • You can supplement your fish's regular diet with vegetables such as zucchini, spinach, and peas. Just remember to cook or blanch the veggies first; if you don't, they'll be difficult for your fish to digest.

Offering a variety of foods is key to keeping your fish healthy and preventing nutrient deficiencies. Pay attention to what they seem to prefer eating and offer more of those items. As with any pet, it's important to keep their environment clean – be sure to remove uneaten food from the water regularly.

Only give your live food sources foods that they can eat easily. This way, you won't have to worry about them choking on something too big or letting escape anything too small and risk water contamination.

The best way to make sure your Koi Angelfish are getting live food is by culturing it yourself. To do this, set up a small aquarium with just a few fish or shrimp in it. Once the culture has been established, you can add it to your main tank.

Koi Angelfish

Koi Angelfish Diseases

Angel fish are delicate creatures, and if not properly taken care of they can succumb to disease quickly. It is essential to be vigilant in watching for early signs of infection or distress. Some common ailments that your Angelfish might face include:

  • Ich: Also known as White Spot Disease, Ich is a protozoan that appears on fish in the form of white dots. The number one cause of ich among angelfish is usually a swift temperature change in their water or stress caused by other fishes. However, placing plants or other similar fish into an inadequate tank can taint all the angelfish and result in Ich. If gone untreated, this disease has a high chance of causing fatalities among affected fish, so taking immediate action is key.
  • Fin Rot: Fin rot is a bacterial infection of a fish's fins. It can be caused by unclean water conditions, such as high levels of ammonia or nitrite. Additionally, fin rot can occur if the fish are kept with other fishes that nibble at their fins, which results in physical damage. If left untreated, fin rot will spread to the fish's body and be deadly.
  • Dropsy: Dropsy, often found fish condition which is swollen from too much fluid, can have numerous causes like kidney failure or infection. Antibiotics could help the fish recover; however, if not successful then the only other option would be to put it down.
  • Velvet Disease: Poor water conditions, new fish, or plants often lead to a fish infection called velvet disease. This is when they develop a velvet-like coating. To treat this, quarantine the fish and apply copper sulfate treatment.
  • Angelfish Hexamita: Aquarists need to be on the lookout for Hexamita, or Hole-in-the-Head Disease. This disease is caused by a rapidly multiplying parasite, and if left untreated it can kill your angelfish and quickly spread to other fish in freshwater aquariums. To quarantine infected fish, you can raise the water temperature gradually until it reaches 90°F, or treat the aquarium with salt.

Symptoms of Disease in Angelfish

It is important to monitor your fish for any signs of disease. Some of the more common symptoms to watch out for include:

  • Loss of appetite
  • Lethargy
  • Clamped fins
  • White spots on the body and/or fins
  • Discolored patches or lesions on the body or fins
  • Raised scales
  • Red streaks in the fins
  • Holes or lesions on the body, head, or fins

If you do notice any of these symptoms, it's best to take immediate action to treat the fish and prevent further spread of infection.


Preventing the disease from affecting your Koi Angelfish is the best way to take care of them. To do this, follow the following steps:

  • Maintain a healthy and consistent water temperature.
  • Perform regular water changes to keep your tank clean.
  • Do not overfeed as this can cause food particles to decay in the water, leading to infection.
  • Avoid overcrowding or placing incompatible fish together as they can easily stress each other out.
  • Periodically check your tank for any signs of disease or distress.
  • Periodically check your tank for any signs of disease or distress.
  • Quarantine new fish and plants before adding them to the main tank.

By following these steps, you can help keep your Koi Angelfish healthy and free from disease!


The sooner you detect the symptoms in your angelfish, the better chance you have of successfully treating the disease.

Some treatment options for diseases that target angelfish are:

  • Freshwater dips and/or baths
  • Antibiotics
  • Copper sulfate treatments
  • Salt treatments
  • List Element

• Raising temperatures in the tank to 90°F (32°C) If you are unsure of how to treat your Koi Angelfish, make sure you consult a professional. It is important that you take immediate action when the disease is detected so that it can be treated before it's too late!

Koi Angelfish Breeding

There are a few key things to remember when breeding Angelfish: feeding them well and giving them the opportunity to choose their mate. Male and female fish can be tricky to tell apart, so letting them pick may be your best bet. Another way you can identify males from females is that females' eggs will cause their abdomen to swell just before they hatch.

Before you start breeding your angelfish, you need to condition them first. This involves preparing their bodies and the tank for breeding by changing their diet and environment. The whole process generally takes 4-8 weeks. To begin conditioning your fish, improve their diet by adding more protein and live foods. Also, make sure the water parameters (like pH levels) in the tank are good for breeding conditions.

Before they mate, parents work together to clean a proposed site - this could be anything from a leaf to slate. Once the female is ready to lay her fertilized eggs, she does so in rows. To improve their chances of survival, both parents take turns cleaning off any dirt or rot that might threaten the health of the eggs.

Koi Angelfish breed for life and work together to rear their young. However, sometimes when under stress or due to other external factors, breeding pairs will consume eggs as well as any small fish nearby. Because of this exception, some professional breeders have had to adjust their methods in order to accommodate these situations.

In order to hatch your eggs, put the leaf or slate they were spawned on in a container with water from their initial tank. Next, add an air stone so there is a stream of bubbles for circulation and cleansing. If you want to be extra cautious, adding fungicide will eliminate any fungus present and stop fungal infections.

Many breeders put newly born fish, called fry, in tanks with lots of places to hide until they're big enough to defend themselves from predators.

Koi Angelfish Fry Care

There are a few easy steps you can take to make sure your Koi Angelfish fry stays healthy and happy. Providing them with hiding places is crucial; live plants or pieces of driftwood work great. In addition, feeding them a nutritious diet is key; live brine shrimp or daphnia works well for Koi Angelfish fry. To keep the habitat clean, you'll need to change the water regularly and remove any ammonia or nitrates. Patience is also key; Angelfish can take up to 12 months before they're fully grown, so don't get discouraged if their growth rate seems slow.

Koi Angelfish

Frequent Questions

What is a koi angelfish?

Koi angelfish are colorful freshwater fish native to South America. They are highly sought after in the aquarium hobby for their vibrant colors and peaceful nature.

What is the ideal water temperature for koi angelfish? 

The ideal water temperature for a koi angelfish tank is between 75-82°F (24-28°C). Anything higher than this could make them stressed or ill, so it's important not to let the temperature get too high. Additionally, since Koi Angelfish come from tropical climates, they do best with aerated warm water tanks with plenty of hiding places.

How do I tell if my koi angelfish is male or female?

It can be difficult to tell the difference between males and females, but one way is to look for signs of female egg production. If her abdomen is swollen or you see eggs in her mouth, then she is likely a female. Males tend to have broader heads and larger dorsal fins than females. Additionally, when they are preparing to breed, males will often swim around females in circles as a courtship ritual.

What kind of food do koi angelfish need?

Koi Angelfish generally require a diet high in protein. Live brine shrimp and other small live foods such as daphnia are ideal for young fish, while adult Angelfish prefer tubifex worms, bloodworms, and other frozen foods. They also benefit from a small amount of vegetable matter in their diet, such as cooked peas, zucchini, or cucumber slices. Additionally, it's important to avoid overfeeding Angelfish; too much food can cause them to become overweight and unhealthy.

When do koi angelfish reach maturity?

Koi Angelfish typically reach sexual maturity between 6-12 months of age. However, they may not be ready to breed until they are around two years old. It's important to note that only a handful of fish produced each spawn will survive into adulthood; the rest will perish due to predation or environmental factors like poor water conditions. This is why it's essential for prospective breeders to take careful precautions when hatching and raising fry.

How to care for koi angelfish?

Koi Angelfish requires a spacious tank with plenty of places to hide and explore. They need high-quality, clean water that is between 75-82°F (24-28°C) and have sufficient oxygen levels. Additionally, they should be provided with a varied diet of live, frozen, and vegetable matter foods. To ensure their general health and well-being, it's important to perform regular water changes and keep an eye out for signs of disease, such as fungal infections. Also, be sure to provide sufficient space between multiple Koi Angelfish so that they don't compete for food or territory. Lastly, providing them with plenty of hiding places is key; live plants or pieces of driftwood work great. With proper care and attention, Koi Angelfish can be a beautiful addition to any home aquarium.

How big does a koi angelfish get?

Koi Angelfish can grow up to 6 inches (15 cm) in length. However, it is important to note that they may take up to a year or more to reach full size. Therefore, it's important not to get discouraged if their growth rate seems slow; these fish need time and patience for them to achieve their full-size potential. Additionally, it's important to provide them with a spacious tank or pond so they can have enough room to swim and explore. A tank of at least 30 gallons (114 liters) is recommended for a single Koi Angelfish. With these care tips in mind, you can enjoy watching your Koi Angelfish grow and mature into a beautiful adult!

How expensive is the koi angelfish?

Koi Angelfish can vary in price depending on their size and quality. Generally, these fish range between $9-20 USD for one small Koi Angelfish. Prices for larger or more colorful specimens will be higher than that. Furthermore, since they are relatively rare compared to other freshwater species, the cost may be even higher if you are looking for a specific type of Koi Angelfish. However, if you are patient and diligent in your search, you should be able to find the perfect fish for your aquarium at an affordable price.

Are koi angelfish cichlids?

Koi Angelfish are not cichlids, but they do belong to the same family (Cichlidae). While both fish share some characteristics such as a large dorsal fin and colorful scales, Koi Angelfish have longer bodies and more slender fins than other cichlids. Additionally, their behavior is typically less aggressive compared to other cichlids, making them better suited for community aquariums. Despite their differences, both Koi Angelfish and cichlids are popular choices among freshwater fish hobbyists!

Are koi angelfish aggressive?

Koi Angelfish are semi-aggressive and should not be housed with other aggressive species. They can become territorial and may fight each other over space or food if they are overcrowded in their tank. If this happens, it is important to separate the fish as soon as possible to prevent any unnecessary stress or injury. Additionally, it's best to only keep one male Koi Angelfish in a tank, as two males can become territorial with each other. With proper care and attention, Koi Angelfish can be peaceful and enjoyable additions to any home aquarium.

Summing Up

 Koi Angelfish is an attractive species of freshwater fish with unique colorations and patterns. They are known for their peaceful nature but can become territorial if housed with other aggressive species. This angelfish has been bred for its black-and-white mottled coloration. Some specimens may have gold markings on the head, and young ones may have a red hue beneath the eyes that fades with age. Although they can be expensive, they make a great addition to any home aquarium if you provide them with the right environment and care. Make sure to keep their tank clean, feed them high-quality food, and give them plenty of space to swim and explore. With these simple tips, you can look forward to watching your Koi Angelfish thrive and grow into a beautiful adult.

Sarah Robertson

I am a passionate blogger who also happens to be a fish keeping enthusiast. Writing about my hobby is something that I absolutely love to do, and it's no secret that my chosen topic is always centered around fish keeping.

Sarah Robertson

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