Reef-safe aquarium fish

Reef-safe fish leave corals alone as a matter of course. Some still eat very small ornamental shrimp, crabs or snails, so check the profile before you mix them. These profiles cover species rated reef safe, with tank size, temperament and any cautions to watch for.

Tank size: 5–396 gal; 5 gal (19 L) to 396 gal (1,500 L); half the list needs 30 gal (115 L) or more
Temperature: 73–81°F; 23–27°C, most of the list
pH: 8.1–8.4; Most of the list
Difficulty: 120 easy; 55 medium · 17 difficult
Temperament: 101 peaceful; 77 mostly peaceful · 14 aggressive

192 species and 25 varieties

Start here

A reef-safe starter list

Reef safe means the fish does not eat corals as a matter of course. Some reef-safe fish still eat very small shrimp, crabs or snails, or nip clams and corals when underfed. Check a fish's profile before you add shrimp, snails or clams. These six are marked reef safe and easy or beginner. The ocellaris clownfish and the royal gramma are the usual first pair, both 3.1 inches (8 cm). The firefish hovers in mid-water at 3.5 inches (9 cm) in 20 gallons (75 liters). The green chromis is a peaceful schooling damsel for 30 gallons (115 liters). The Banggai cardinalfish hangs among the rock at 3.1 inches (8 cm), and the tailspot blenny is a 2.4 inch (6 cm) fish for 20 gallons (75 liters) that perches and watches.

The rule

What reef safe means in the catalog

Every saltwater profile but three brackish ones carries one of three marks, and freshwater profiles carry none. Reef safe means the species leaves corals alone, and that is the mark this list filters on. Some reef-safe fish still eat very small ornamental shrimp, crabs or snails, the Christmas, radiant and eightline wrasses among them. Caution means the fish usually behaves but has a known habit. A dwarf angel may nip clam mantles, and a clown goby irritates the coral it lives in. Not reef safe means the fish eats or nips as a matter of course, and those fish have the FOWLR list. Reef safe says nothing about other fish: the maroon clownfish and several damsels are reef safe and aggressive at the same time.

01
Reef safe
Leaves corals alone, though a few take tiny shrimp or nip clams
02
Caution
Usually fine, with a known habit on the profile
03
Not reef safe
Eats or nips, and belongs in a FOWLR tank
04
Not the same as peaceful
Temperament is a separate mark

Movement

Tangs, wrasses and a school for a bigger reef

The grazers and open-water swimmers need length. The tomini tang is the most compact tang at 6.3 inches (16 cm) for 70 gallons (265 liters). The kole tang comes next at 7.1 inches (18 cm) for 79 gallons (300 liters). The scopas tang lists the smallest tank of the Zebrasoma tangs, 90 gallons (340 liters) for 7.9 inches (20 cm), and is marked easy. The mimic tang, also marked easy, reaches 11.4 inches (29 cm) in 129 gallons (490 liters). The fairy and flasher wrasses are the reef-safe wrasses by nature, feeding on plankton in the water column: the exquisite fairy wrasse lists 90 gallons (340 liters), McCosker's flasher wrasse 55 gallons (208 liters). The melanurus wrasse hunts flatworms and pests on the rock at 5.5 inches (14 cm). The schooling bannerfish and the pyramid butterflyfish are the two butterflyfish marked reef safe. Both are peaceful schooling fish, 8.3 and 7.1 inches (21 and 18 cm) for 124 gallons (470 liters).

Small reefs

Reef-safe fish for 20 to 30 gallons

The neon goby stays at 2 inches (5 cm) and lists 11 gallons (40 liters), and the sharknose goby is its 1.6 inch (4 cm) cousin for 13 gallons (50 liters). Helfrich's firefish is the small, peaceful firefish at 2.4 inches (6 cm) for 20 gallons (75 liters). The yellow cardinalfish and the pictus blenny both stay at 2 inches (5 cm) in 20 gallons (75 liters). Hector's goby grazes hair algae at 3.1 inches (8 cm) and lists the same tank. None of them touches a coral.

Watch out

Reef safe is not the same as peaceful

The maroon clownfish is marked reef safe and aggressive, a 6.7 inch (17 cm) fish that owns its anemone and the tank around it. The blue damsel is marked beginner, reef safe and aggressive, and so are the three-stripe and four-stripe damsels, which is why they are missing from the beginner list. The bicolor dottyback is a 2.8 inch (7 cm) fish that will harass anything its size, and the blue velvet damsel reaches 5.9 inches (15 cm) with the same temper. They all leave corals alone. They do not leave other fish alone.

By the numbers

Smallest

Largest

Easiest to keep

Most peaceful

Fits a 20 gallon tank

Fits a 30 gallon tank

FAQ

Common questions

What does reef safe mean?

It means the fish is not known to eat corals as a matter of course. Some reef-safe fish still take very small ornamental shrimp or nip clams and corals when hungry. It is the top mark of three; the middle mark, caution, means the fish usually behaves but has a known habit.

Are clownfish reef safe?

Yes. Every clownfish in the catalog is marked reef safe, and none of them needs an anemone. The maroon clownfish is the one marked aggressive, and a mature one can tear up corals and anemones. Add it last and keep no other clownfish except its mate. Choose tank mates that stay out of its way, such as bottom-dwelling gobies or blennies. It may still bully or kill smaller fish in time.

Are tangs reef safe?

Yes. Every tang in the catalog is marked reef safe, and a well-fed tang leaves corals alone. An underfed one may nip LPS or soft corals, so keep dried algae available. The catch is size: the scopas tang lists 90 gallons (340 liters), the mimic tang 129 gallons (490 liters), and the unicornfish need far more.

Which wrasses are reef safe?

The fairy, flasher and leopard wrasses are marked reef safe. The six-line, fourline, eightline, melanurus, Christmas and radiant wrasses, the twospot hogfish and the two cleaner wrasses are marked reef safe too. The Christmas, radiant and eightline wrasses still eat small ornamental shrimp, the habit that gives the adorned and yellow coris wrasses a caution. The Thalassoma wrasses and the red coris wrasse are marked not reef safe.

Are dwarf angelfish reef safe?

Every dwarf angel in the catalog carries a caution, because one may nip clam mantles and fleshy corals. The angels marked reef safe are the five Genicanthus swallowtail angels.

Are damsels reef safe?

Most are marked reef safe, but many are aggressive toward other fish. The domino and white damsels carry a caution and are marked aggressive. The blue, three-stripe, four-stripe, neon, Fiji blue devil and blue velvet damsels are marked reef safe and aggressive. The azure, yellowtail, sapphire and Talbot's damsels are among the mostly peaceful ones, and the chromis are marked peaceful.

Index