Green Chromis Fish Care (Chromis Viridis)

Green chromis fish

Last updated on August 10th, 2022 at 06:20 pm

Green chromis fish, also known as the blue green chromis (Chromis viridis), are popular aquarium fish due to their bright blue and green coloration, with orange or yellow on the fins. Their care requirements are easy, making them an ideal first saltwater fish for new aquarists, as well as an attractive addition to more experienced reef tanks.

They can be kept singly or in pairs, but make sure to leave enough swimming room between individuals. Green chromis school size can be 2 or 3 in a tank. A 30-gallon tank will house two fish comfortably, but adding a third individual would require a larger tank of at least 50 gallons in size.

Chromis viridis is an omnivorous marine fish that lives in the Indo-Pacific Ocean as well as parts of Australia. They are easy to identify by their unique orange and blue stripes, which are dark on their top half and fade into white on their belly. The species can reach up to 8 inches long, making it suitable for home aquariums if cared for properly.

Origin and descriptions

Native to clear tropical and subtropical waters, they are found throughout much of Southeast Asia. Blue green chromis fish are relatively small, reaching lengths of between 3 and 4 inches. They have distinctive coloration and patterns which can vary widely between individual specimens.

While young, a blue green chromis fish is predominantly dark with light markings around its eyes and pectoral fins. As it ages, these spots will begin to disappear while additional spots appear on its body. The most distinctive feature of a blue green chromis fish is its tail fin; instead of being flat like most other species in their family, green chromis fish’s tail fin has two lobes protruding from it that resemble butterfly wings.

Species profile

Green chromis fish

The blue green chromis fish belong to the family Pomacentridae, and are also known as reef-dwelling damselfish. They are found in tropical waters of both the Pacific and Atlantic oceans, and usually inhabit shallow lagoons and coral reefs.

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This Chromis fish can grow up to 10 cm in length, with a life span of 8-15 years.  They are omnivorous, feeding on animals, algae, and plankton. These beautiful creatures have a metallic sheen that reflects light from their scales. Their colors range from silvery white to golden yellow.

Green chromis fish scientific name

The scientific name of the blue green chromis fish is Chromis viridis

Common names

Blue green chromis, green chromis fish, green chromis viridis, or just chromis fish.


A saltwater fish called the Green Chromis can be found on shallow reefs in the South Pacific and Indo-Pacific Oceans. They spend most of their time on coral reefs and lagoons, where they are found in large shoals. These fish can be found in shallow waters with a depth of about a meter but can be found as deep as 12 meters.

Our recommendation is to match the aquarium you place your Green Chromis in as closely as possible to their natural habitat.  They spend a lot of time in coral formations, so you should fill their aquarium with coral if they like hiding in it, playing in it, and even living in it. Try corals like Acropora if you are just starting out.

Chromis viridis is considered reef safe, which means you can add them to your existing marine tank without damaging or stressing nearby coral. The only downside is that these creatures don’t tolerate high levels of nitrates well, so make sure you perform regular water changes to keep your tank clean and healthy.

Green chromis size

Blue green chromis fish can grow up to 3-4 inches (8-10 cm) in length.

Tank size

Due to their small size, green chromis fish will thrive in a tank size of around 30 gallons (114 liters).

Tank requirements

When keeping a couple of them you’ll need an aquarium of 30 gallons. Nevertheless, for a shoal to be kept at all, a minimum of 60 gallons is required. A Blue Green Chromis can be found swimming in all levels of the water column in an aquarium, but they are active swimmers and will occupy a majority of the middle of the tank; they will rank as one of the busier species of fish in your tank.

Blue Chromis Fish Care (Chromis Cyanea)

Water temperatures should range from 72° to 82°F, with pH ranges of 8.1-8.4, and specific gravity should be 1.03 to 1.04.

The tank should also have plenty of coral and some plant sections covered in algae so the fish can graze on it.

In contrast to freshwater fish, saltwater fish do not require much water movement. To be on the safe side, you should make sure that the current isn’t too fast.

Green chromis tank mates

Green Chromis can be an excellent community fish; they are even capable of creating a school with other green chromis species.

Fish such as Basslets, Butterflies, and Blennies are ideal to keep with them in community tanks.

Are green chromis reef safe?

Yes, green chromis are reef safe and can be kept with corals.

They can be kept with other somewhat aggressive fish like tangs, however, it is important to always remember that the larger fish will rule the tank.

The Green chromis species will devote almost all its time to the top corner of the tank if it is being bullied. When this happens, you need to take action; either remove your fish or the bully.

Green chromis breeding

Green chromis fish

Blue green chromis are fairly easy to breed in captivity. To encourage breeding, increase lighting during daylight hours and raise the water temperature to 82 degrees Fahrenheit.

When aquarium conditions are ideal and there are no predators in the tank, Blue Green Chromis will sometimes breed in captivity. Several female Blue Green Chromis will lay eggs at the same time into a nest that is prepared by a male in the sand bed.

After fertilizing the eggs, the males tend to the nest and guard the eggs until they hatch after a few days.

The male chromis fish typically eat the remaining unfertilized eggs or those that do not hatch.

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If your blue green chromis do not start reproducing after several months, remove all the decor from their tank and replace it with large chunks of live rock. Some hobbyists recommend adding live sand as well for improved filtration, though others argue that sand will clog filter intakes more quickly than other types of substrate.

Are green chromis aggressive or peaceful?

They are peaceful, but they do have a tendency to get in a squabble once in a while. But even then, these fights usually only occur between two fish of the same species. This is because green chromis fish are not particularly territorial and prefer to swim as individuals rather than in groups. Because of their peaceful nature, they are great additions to reef tanks with docile invertebrates like clams or shrimp.

Green chromis care guide

Green chromis fish

Green chromis fish are fairly easy to care for, and with a little bit of research, you can easily set up a beautiful and healthy habitat for your fish. Since they live in warm water, you’ll want to keep your tank at around 72 degrees Fahrenheit. They need an established aquarium with plenty of swimming room, so an efficient filtration system is important for their health. The filtration will also remove any waste products that may trigger algae growth in your tank.

Green chromis food

Like many fish, Chromis viridis are omnivores, they eat a range of small aquatic animals. In particular, they consume algae, copepods, and snails. They need a diet rich in meaty foods like brine shrimp, mysis shrimp, or finely chopped krill. A varied diet is recommended as well as vitamin supplements from time to time.


Green chromis fish

The blue green chromis fish are hardy species that can live between 8-15 years when properly cared for in aquariums with good water parameters.

Parasites and diseases

Green chromis fish can be affected by a wide variety of parasites and diseases. This can include internal parasites such as ich and worms, external parasites such as marine invertebrates, fungal infections, bacterial infections, and protozoan infections.

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Parasites and diseases should always be treated to avoid further damage to your fish. If you notice that your green chromis are displaying any signs of disease or parasite infection, then it is important that you act quickly in order to treat them before they become too ill.


Luckily, Chromis viridis is small and evasive enough to easily avoid many predators; however, it can fall prey to larger fish. They are targeted by large predators such as barracuda, mackerel, tuna, and wahoo. They may be eaten by snapper, grouper, and other larger fish.

Are green chromis good fish pets?

Green chromis fish species, like many marine animals, make good pets. They are relatively easy to take care of and don’t require a lot of money or a large tank. But they aren’t your average pet fish; they will bite their owner if they feel threatened.