Soft corals are found in the world’s oceans but are most commonly discovered in the deep sea, tropics, and subtropics, as well as polar waters. The most common names used for subsets of soft corals are “sea fans” and “sea whips.”

They are soft and bendable and are usually compared to plants or trees in their appearance. They do not build reefs as their hard coral counterparts do. But they do live in similar colonies.

Alcyonium acaule, an alcyoniid
Alcyonium acaule, an alcyoniid


What are Soft Corals?

Soft coral is a term used to describe a variety of species that have one thing in common and they lack a hard skeleton. They are the opposite of hard corals, which have a skeleton made of calcium carbonate. But this doesn’t mean that all soft corals are entirely devoid of hard structures. Some have tiny, hard pieces of the skeleton within their larger, fleshy bodies.

Most depend on a symbiotic relationship with zooxanthellae, an algae type that lives inside coral. Others, like Mushroom Corals, depend on the nutrient they can extract from the water and from eating other organisms.

Alcyonacean image showing individual polyps
Alcyonacean image showing individual polyps

Credit: Clark Anderson,  Creative Commons Attribution-Share Alike 2.5 Generic license

This means that if you’re planning on a soft coral variety in your aquarium, you are going to have to figure out how exactly they feed and what you need to supply them with.

Many soft corals live in nutrient-rich waters with low light but are easily collected and included in aquariums. They are easier to transport and harder to damage than hard corals. But they can be troublesome when it comes to preventing them from spreading all over your aquarium. It takes an understanding of each coral’s unique features in order to best care for it. 

Soft Coral Types 

There are many different kinds of soft coral in the world’s oceans that are available for aquarium hobbyists. They include:

  • Ricordea
  • Zoanthids
  • Palythoa
  • Discosoma
  • Pachyclavularia
  • Alcyonium
  • Cladiella
  • Lobophytum
  • Sarcophyton
  • Sinularia
  • Nepthea


Soft Coral Color 

Soft corals come in every color you can imagine. But, the colors may be somewhat limited depending on the species. For example, Green Star Polyps only come in shades of green, and Toadstool Leather Coral is almost always brown, yellow, or tan. 

Paramuricea clavata, a paramuriceid
Paramuricea clavata, a paramuriceid

Credit: Parent Géry, Creative Commons Attribution-Share Alike 3.0 Unported license

Other varieties, like Zoanthids, are much more diverse in the colors and patterns they grow into. They come in bright purple, blue, green, yellow, pink, and more. Sometimes, they even appear neon in dark lighting.

Popular Soft Coral for Aquariums 

Soft coral is one of the most popular additions to aquariums. Some of the most popular varieties include:

Zoanthids

A variety of Zoanthid
A variety of Zoanthid

Zoanthids are a soft coral variety that is very easy to grow and only requires a moderate water flow. They come in a wide variety of colors and patterns, some of which are incredibly expensive. They are considered easy to moderate-level coral to take care of. 

Mushroom Corals

A beautiful mushroom coral
A beautiful mushroom coral

Mushroom Corals are a very popular type of coral for aquarium hobbyists. They are easy to frag and come in a variety of colors, including green and orange. They are a great choice for a beginner who has little experience fragging coral. But, if you aren’t careful, they can grow out of control. 

Toadstool Leather Coral

A type of rough leather coral
A type of rough leather coral

Credit: Diego Delso, delso.photo, License CC-BY-SA

The Toadstool Leather Coral is a very species of coral that can grow up to 2 feet in length. But they are very easy to take care of and prevent rapid overgrowth. They usually come in green, brown, or yellow, with tentacles of different lengths. These corals do best in a tank with moderate to high water flow. 

Green Star Polyps

Green Star Polyps
Green Star Polyps

Credit: PilarMeca, Creative Commons Attribution-Share Alike 3.0 Unported license

The Green Star Polyp is a fast-growing soft coral that can prove troublesome or exciting depending on the hobbyist. They do best on a rock island that can help prevent them from overgrowing and taking over your tank. They are beautifully green in color and are native to the Indo-Pacific. 

Pulsing Xenia

Pulsing Xenia
Pulsing Xenia

Credit: Diego Delso, delso.photo, License CC-BY-SA

The Pulsing Xenia is easy coral to keep that candy situated in the bottom, metal, or top of the tank. They are originally found throughout the Indo-Pacific, including around Fiji, Australia, and the Solomon Islands. They are the second most popular soft coral type to keep in an aquarium. They are usually pink to purple in color. They are known for the way they pulsate their polyps, at least for a time, and can help create movement in your tank. 

FAQs 

What is considered a soft coral?

Soft corals come in many different shapes and sizes. Sea fingers and sea whips are some of the most common. A coral that lacks a hard skeleton is usually considered a variety of soft coral.

Are soft corals good for beginners?

Yes, corals are usually considered good for beginner aquarium hobbyists. But, not all soft corals are the same. They may take their nutrients in different ways and, if not contained, grow out of control and take over your aquarium.

What is the difference between hard coral and soft coral?

The main difference between hard coral and soft coral is that hard corals have a calcium carbonate skeleton and soft corals are more fleshy in, like those large hard interior structures.

What is soft coral used for?

Many varieties of soft coral are harvested and used as decoration in aquariums. Wild soft corals attract tourism in the form of diving and snorkeling trips.

How much light do soft corals need?

Most soft corals prefer moderate light in aquariums. They usually do best at the bottom of the tank, especially if you have powerful lights. But, if you have dimmer lighting around your aquarium you can place them in the middle or at the top.