10 of the Best Reef Safe Fishes for a Marine Aquarium

Just because a marine fish lives in the ocean does not mean it’s a good choice for a reef aquarium. Reef-safe fish are always in demand because their diets don’t include decorative corals. But which fish should you start with when shopping for reef aquarium inhabitants?

The 10 Best Reef Safe Saltwater Aquarium Fish

It’s important to choose reef-safe fish when setting up an aquarium with corals. Too many reef dwellers enjoy munching on the delicate bodies of hard and soft corals. Other non-moving invertebrates, like feather duster worms and giant clams, are also in danger if you add the wrong fish to your reef aquarium.

Blue Green Chromis

The delicate pastel green and blue tones make the blue green chromis a favorite of aquarists of all skill levels. Like all damselfish, this species is hardy and an excellent fish for beginners. You can even cycle a new reef aquarium with damselfish are they are resistant to ammonia.

What’s more, chromis damselfish are peaceful fish. Many of the other genera, especially the three spot damselfish (Dascyllus trimaculatus) and its relatives, are very aggressive fish. Chromis viridis are fast growers and schooling fish that need to be kept in groups of at least 6 individuals!

• Scientific Name: Chromis virdis
• Length: 3 inches
• Minimum Tank Size: 20 gallons

Ocellaris Clownfish

There are many species of clownfish. But the small, bright orange and white variety that comes to most people’s minds is the ocellaris clownfish.

Ocellaris clownfish are poor swimmers, wobbling through the water column using their pectoral fins. This endearing behavior is due to their preference for living in the tentacles of sea anemones.

You don’t need to have an anemone if you want clownfish. But watching their symbiotic relationship in action is truly incredible.

A few of the larger species of clownfish, including the maroon clownfish, are more aggressive towards tank mates. But all clownfish are reef-safe fish that won’t harm corals or live rock.

• Scientific Name: Amphiprion ocellaris
• Length: 3 inches
• Minimum Tank Size: 20 gallons

Six Line Wrasse

Most wrasses are predatory towards fish and invertebrates. But the tiny six-line wrasse is an exception that won’t eat corals or other prized invertebrates.

They are a great saltwater fish to add to a reef tank that is infested with pests, in fact. Six line wrasses will eat pyramidellid snails, bristle worms, flatworms, and other reef tank pests.

Despite being small fish, the six-line wrasse is very active. 30 gallons is a bare minimum tank size, with more being better. Extra space also gives any tank mates room to flee. Six line wrasses are semi-aggressive to aggressive in personality.

• Scientific Name: Pseudocheilinus hexataenia
• Length: 3 inches
• Minimum Tank Size: 30 gallons

Firefish Goby

The firefish goby is also known as the dartfish. These reef-safe saltwater fish will dart back and forth from open water to nearby hiding places. When not feeling shy, firefish gobies will signal to each other using their flag-like dorsal fins.

The more hiding places you offer these hardy fish, the safer the firefish goby will feel out in the open. You should feed them brine shrimp, zooplankton, and other appropriately sized food.

Firefish normally live in mated pairs. Since sexing them visually is impossible, it is difficult to get a peaceful match in a home aquarium. If you look carefully, you may find a pair living together even in pet store saltwater aquariums.

But adding more than two to the same tank can be disastrous. Firefish are very aggressive towards their own kind.

• Scientific Name: Nemateleotris magnifica
• Length: 3 inches
• Minimum Tank Size: 20 gallons

Blue Tang

Blue tang, hippo tang, dory fish…These are one of the most popular saltwater fish in the entire world. And for good reason: the vibrant blue and deep black of these fish is incredible.

Blue tangs are one of the larger reef-safe fish you can add to your saltwater aquarium. They are also one of the less aggressive tangs and won’t bother their tank mates. You can even keep more than one blue tang so long as your reef tank is large enough.

Tangs are avid algae eaters as well. Algae tends to overgrow and smother corals if not maintained.

That said, blue tangs eat more zooplankton than algae. So don’t rely solely on it as a food source. If you want a dedicated algae-eating member of your clean-up crew, there are better tang species for your reef tank.

• Scientific Name: Paracanthurus hepatus
• Length: 12 inches
• Minimum Tank Size: 150+ gallons

Midas Blenny

One look and it’s easy to see how the midas blenny gets its name. Named after the Greek legend whose touch turned anything to gold, the radiant orange tones of this reef-safe fish are irresistible.

Midas blennies are peaceful aquarium fish. But they may fight with other blennies and other fish species with a similar body shape. If you enjoy these fish, choose species that are very different in color.

Also, make sure that any saltwater tank with a midas blenny has plenty of hiding spaces. The blenny will choose a large hole as its favorite, poking its head out to watch the world go by. They can be territorial if other cavity-dwelling aquarium fish try to enter their favorite cave!

• Scientific Name: Ecsenius midas
• Length: 4 to 6 inches
• Minimum Tank Size: 30 gallons

Purple Tang

The purple tang is one of the most elegant reef-safe fish in the trade. While they are fairly hardy fish, tangs have specialized dietary needs.

Purple tangs are herbivorous, feeding on algae and kelp in the wild. By eating algae that grows on live rock, tangs help keep the corals in your reef tank clean and able to expand outwards.

If they aren’t given enough vegetable matter, tangs develop hole in the head disease. The disorder is caused by poor nutrition.

Adding strips of algae and flakes fortified with spirulina to the diet of a tang will reverse its course. If you can, growing macroalgae in a refugium below your reef tank offers an endless source of food as well!

• Scientific Name: Zebrasoma xanthurum
• Length: 8 inches
• Minimum Tank Size: 90+ gallons

Banggai Cardinalfish

The Banggai cardinal fish is the only type of cardinal fish that is active during the day. Its diurnal traits and eye-catching patterns make it an excellent addition to any saltwater aquarium.

Their patterns look bright yet are actually a form of camouflage. Banggai cardinalfish live among the black spines of Diadema sea urchins. The fish crowd in close to the sea urchin when a predator comes near.

As schooling fish, you should keep them in groups of 6 or more individuals. These reef-safe fish eat mostly small invertebrates. They are also one of the easier saltwater fish for beginners to breed!

• Scientific Name: Pterapogon kauderni
• Length: 3 inches
• Minimum Tank Size: 30 gallons

Royal Gramma

As one of the smallest reef-safe fish, the royal gramma can be found in pet stores the world over. Grammas are peaceful towards their tank mates but very aggressive towards each other.

They do spend a lot of time out in the open. But grammas need a nearby cave to feel safe and unstressed. They will fight with other cavity dwellers if there aren’t enough hiding places.

These Caribbean fish are quite hardy and need little in the way of specialized care. Royal grammas will eat standard flake and pellet food with gusto.

They are known to be jumpers, however. So make sure that your lid is secure and no obvious holes can be seen from inside the tank!

• Scientific Name: Gramma loreto
• Length: 3 inches
• Minimum Tank Size: 30 gallons

Powder Blue Tang

Often the showpiece specimen of any reef aquarium, the powder blue tang is a large and impressive fish.

They are a little more sensitive to poor water conditions than the other fish on this list. But if you’re already familiar with providing impeccable water quality for corals then you should have little trouble.

Powder blue tangs should only be added to aquariums that have had 6 months or more to cycle. Even low ammonia levels cause them severe stress.

Powder blue tangs also need plenty of vegetable matter to stave off diseases like hold in the head. They are semi-aggressive to aggressive towards their own kind as well as other tangs.

Tang fights can be very serious. These fish are also called surgeonfish due to the switchblade-like spine along their tails. These razors can inflict bleeding wounds with lightning speed.

• Scientific Name: Acanthurus leucosternon
• Length: 9 inches
• Minimum Tank Size: 125 gallons

Conclusion

Reef-safe fish come in a wide variety of color patterns and sizes. Some are small enough even for 10 gallons of space. While others need 55 gallons or more to feel comfortable.

Some are aggressive but others are very peaceful. There is something to meet the desires of every aquarist on this list of the 10 best reef-safe fish!