What “reef safe” means
A reef safe fish is one that is not expected to eat or damage corals and generally leaves peaceful invertebrates alone. It is a useful starting point, not a guarantee. Individual fish vary, and the label depends on what you keep: a fish that ignores hard corals may still nip at soft corals, clam mantles or small shrimp. Tank size, feeding and the fish’s age also play a part.
“Reef safe with caution”
Many sellers use a middle category, meaning a fish is usually fine but can cause trouble in some tanks. Common examples include:
- Some angelfish, especially dwarf angels. They can pick at corals or clams in some tanks.
- Some wrasses. Many are helpful, but larger ones may eat shrimp, snails and small crabs.
- Some butterflyfish. Certain species are known for eating coral polyps or anemones, so check each species.
- Some larger tangs. They are often considered reef safe, but need a lot of swimming room and can be aggressive toward other fish.
When a care sheet says “with caution,” read it as a prompt to research that species and your specific corals.
Reef safe fish for beginners
The following groups are widely regarded as suitable for reef tanks. Always confirm the exact species and its adult size.
- Clownfish (such as ocellaris and percula). Hardy and often captive-bred. A pair needs a tank sized for their adult length.
- Cardinalfish (such as pajama and Banggai). Slow, peaceful, and often kept in small groups in larger tanks.
- Gobies, including watchman gobies and small clown or neon gobies. See our guide to the best goby for a reef tank.
- Blennies, such as the Midas blenny and some algae-grazing species. Some may nip at large-polyped corals or clam mantles, so observe them.
- Basslets and grammas, such as royal gramma and chalk bass.
- Dottybacks. Many are colorful and hardy, but some are quite territorial toward other small fish.
- Firefish and dartfish. Peaceful, but they jump, so use a tight lid.
- Tangs such as the yellow tang or tomini tang. These are good algae grazers in large enough tanks. See our article on the best algae-eating saltwater fish.
Fish that are usually not reef safe
Fish that commonly eat corals, anemones, shrimp, snails or other tank inhabitants, or that are too large and aggressive for most reef setups, include:
- Many triggerfish
- Most large angelfish
- Many butterflyfish that feed on coral polyps
- Large wrasses and groupers
- Lionfish and other predators that eat small fish and shrimp
- Most pufferfish and boxfish, which tend to nip at corals and eat invertebrates
Is there a reef safe puffer?
Pufferfish tend to eat snails, crabs and shrimp and often nip corals, which is why they are generally not recommended for reef tanks. Some very small species are sometimes kept in specialized setups, but they are usually considered a risk, and their dietary needs are tricky. If you want a reef tank with corals and inverts, most hobbyists choose a different fish.
How to lower the risk when stocking
- Research each species’ diet and temperament, not only the reef safe label.
- Match adult size to your tank.
- Add peaceful fish first and aggressive or territorial ones last.
- Feed enough so fish are not hunting corals and inverts for food.
- Quarantine new fish. Our saltwater fish care guide explains why.
- Watch new fish closely for the first weeks, and be ready to remove one that damages corals.
To think about how different species get along with each other, see compatible reef fish and our list of the best saltwater community fish.