Blue Chromis Fish Care (Chromis Cyanea)

Blue chromis fish

Last updated on July 5th, 2022 at 03:46 pm

The Blue chromis fish, or Chromis cyanea, is one of the most popular species of marine fish kept in saltwater aquariums, but few aquarists have the correct information about how to care for this fish in their tanks

They are hardy fish and can be quite entertaining, but they require more attention than some other species. Fortunately, with proper care and maintenance, you’ll be able to have these fish swimming around your tank for years to come!

They have been around since the early 2000s and it’s still popular among aquarists today. Not only are they beautiful, but they’re pretty easy to care for, too!

This Blue chromis fish facts will show you all you need to know about this species of saltwater fish.

Origin and descriptions

Blue chromis fish are a group of fish known as damselfish. Damselfish live in tropical reefs, where they can often be seen in large schools. The fish are part of a larger family known as Pomacentridae, which also includes royal grammas and damsels.

They are small fish that grow up to 4 inches long. These fish are very hardy fish that do well in saltwater aquariums.

The most important thing when caring for Blue chromis fish is keeping them with other peaceful tank mates so they don’t get picked on by more aggressive species.

Species profile

Blue chromis fish

The Blue chromis fish belong to the family Pomacentridae, which also includes damselfish and clownfish. They are blue in color with black color on the back, running from their head to their tail. They are native to shallow reefs in tropical waters, but have been introduced into many other areas of the world, including Hawaii.

These fish can be kept in captivity at temperatures between 72 and 82 degrees Fahrenheit (22-28 degrees Celsius). They can grow up to 7 inches (18 centimeters) long.

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Scientific name

The scientific name of the Blue chromis fish is Chromis cyanea


Blue chromis fish are shallow water fish that are generally found between 3 and 5 meters deep but can reach depths as deep as 25 meters below sea level. There has also been a record of it at a depth of 60 m below sea level. This marine animal lives on reef surfaces but feeds on plankton in the water columns above the reefs.

Blue chromis fish size

These saltwater fish species are very big, the average size of the Blue chromis fish is 3-4 inches (8-10 cm) in length when fully grown.

Blue chromis tank size

Due to their size, the minimum recommended tank size for Blue chromis fish is 30 gallons (114 liters), as they need room to swim.

Tank requirements

The Blue chromis fish requires specific tank conditions in order to survive and thrive, but there are several things hobbyists can do in their own tanks that will make life easier for these fish.

The aquarium should contain live rock or corals for them to graze on, as well as algae and zooplankton for them to eat.

Keep pH between 8.1 and 8.4. Additionally, keep nitrate levels low (below 40ppm) by limiting feedings and doing partial water changes of at least 20% once a week or more frequently if you notice problems with your tank’s water quality.

Keep ammonia and nitrite levels as close to zero as possible by performing regular water changes, changing filter media regularly, cleaning equipment properly before adding it back into your aquarium, and keeping an eye on how much food is going into your tank.

Finally, be sure to provide plenty of hiding places for Blue chromis fish; they need somewhere safe to retreat when they feel threatened or stressed out.

Tank mates

Blue chromis fish prefer tank mates that are small enough not to be seen as prey by these fish.

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Good tank mates include cardinalfish, fairy basslets, blue tangs, and pajama cardinalfish.

While all fish require tank mates of their own kind, certain fish are more compatible than others. Be sure you choose wisely when deciding on tank mates; Chromis cyanea (Blue chromis fish) may be less aggressive than some other saltwater creatures, but they’re still territorial and protective of their eggs and fry. Choose wisely!


Blue chromis fish

In order to groom their territory, males brush their tails along the substrate and nibble at out-of-place bits with their mouths. In order to attract females, the males typically turn bright blue and do a lateral display, or sometimes countershading with a mix of light and navy-blue colors, as well as swimming up and down in front of the female.

Having been persuaded, the female scoots along the nest site and lays her eggs, and the male swoops down to fertilize them. Thereafter, the female will leave and the male is left to clean, aerates, and protect the nest while the eggs develop.

He will continue to do so until the eggs hatch and the fries are ready to swim on their own, usually around 5 days after hatching.

Newly hatched fry are 0.25-0.5 inches (6-12 mm) long and should be fed a mixture of rotifers, green water, and micro-worms. They will also eat finely crushed flakes or baby brine shrimp if they are available. Feed them at least once a day, more often if they’re growing quickly. Remove any uneaten food after 20 minutes so that it doesn’t pollute your tank with ammonia and waste products.

Are blue reef chromis aggressive or peaceful?

The Blue chromis fish is an extremely hardy, peaceful saltwater fish that requires minimal care and upkeep. They are reef safe and will not harm your corals or other small fish. However, if you do have other aggressive fish in your tank, they can be picked on because of their smaller size. That is why it is important to make sure all of your fish are getting along before you introduce new additions into your tank.

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Blue chromis fish care

Blue chromis fish

The Blue chromis fish is a saltwater fish that requires special care, which means it’s not an ideal species for those in aquaria with community tanks. To learn how to properly care for a Blue chromis fish (Chromis cyanea), you should first ensure that your tank has specific water conditions.

The recommended temperature is 72-78 degrees Fahrenheit, and it should have a specific gravity level of 1.020 or higher and a pH level of 8.0 or higher. If you don’t meet these requirements, consider adding aquarium supplements to keep these levels stable. When setting up your tank, make sure there are plenty of hiding places, these fish prefer dimly lit areas.

They also need rockwork and live rock so they can graze on algae; make sure there are plenty of crevices for them to hide when they feel threatened by other inhabitants in their tank. You will also need a deep sand bed so they can bury themselves when necessary.

What do blue chromis eat?

Blue chromis fish are omnivores, they eat invertebrates and algae in your tank. They’ll also eat freeze-dried plankton and other marine fish food that sinks to the bottom of your tank.

In their natural habitat, chromis eat algae and small invertebrates like crabs, shrimp, and worms

Aim for a balanced diet that includes both wet and dry foods (your fish will pick out what they like). And if you have algae bloom in your tank, plan on feeding more frequently, their mouths are equipped with tiny teeth which help them scrape off algae.

Blue chromis fish lifespan

Blue chromis fish

In captivity, these fish species can leave up to 8-15 years with proper care and good water conditions.

Parasites and diseases

Blue chromis fish can catch a number of diseases and parasites, including flukes and nematodes, but it is difficult to treat these conditions in aquariums.

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An important part of knowing how to care for Blue chromis fish is understanding what parasites and diseases can befall them. Like all marine fish, they’re also prone to parasites such as ich, anchor worms, and flatworms, which are contracted by contact with infected fish or unclean aquariums.

If you notice symptoms of disease, such as redness fish’s body or lethargy, then you may need to move your Blue chromis fish into a quarantine tank, and contact your veterinary doctor immediately.


Even with a healthy diet, young Blue reef chromis fish may fall prey to common predators like triggerfish, jacks, and grunts. To protect them from their natural enemies, keep your fish in a tightly covered aquarium and place them in an area that is free of other fish. Be sure that each individual has their own space as well so they don’t tear each other apart over territory disputes.

Do Blue chromis fish make good pets?

Yes, Blue chromis fish make very good pets; they’re hardy and can live in a variety of saltwater aquarium setups. They’re also easy to feed since they eat most of any food you give them. If you have little experience with marine life and would like to try keeping one as a pet, we recommend trying a Blue chromis fish first. It is an excellent beginner fish.