Coral Frag
A coral frag is a small piece cut, broken, or otherwise separated from a larger parent coral colony, taking advantage of corals’ natural ability to regenerate and grow from fragments. Given time, appropriate care, and stable conditions, a frag will attach to a new surface and develop into a fully independent colony, genetically identical to its parent.
Fragging has become central to the reef keeping hobby, allowing corals to be propagated, shared, and sold among hobbyists, which reduces reliance on wild coral collection and has helped make a huge diversity of coral varieties accessible to home aquarists.
Why It’s Important
- Allows corals to be propagated and shared among hobbyists without harming wild reef populations.
- Takes advantage of corals’ natural regenerative ability to grow new, independent colonies.
- Has driven the wide availability and diversity of coral varieties found in the hobby today.
- Gives hobbyists a practical way to manage colony size, trade, or recover from partial coral damage.
How It Works
Fragging typically involves cutting or breaking off a healthy piece of a coral colony using tools appropriate to its skeletal structure, such as bone cutters for branching stony corals or a sharp blade for soft corals. The resulting frag is then mounted onto a frag plug, disc, or plug of live rock, where it’s given time in stable, low-stress conditions to heal and attach before being introduced into a display tank.
Once attached and growing, a frag behaves just like any other coral colony, gradually expanding in size and eventually becoming large enough to be fragged again if desired.
Coral Frags and Related Concepts
Coral frags are closely tied to coral propagation and frag plugs, the tools most commonly used to mount them, as well as to the broader frag swap and trading culture within the hobby. They’re also connected to coral growth rate, since how quickly a frag establishes itself depends heavily on tank conditions and species.
After fragging, frags are typically kept in a low-flow, stable area, often called a frag rack or frag tank, while they heal and begin attaching to their new mounting surface. This recovery period is important, since a freshly cut frag is more vulnerable to stress, flow damage, or infection than an established colony. Once healed and showing active growth, frags can be moved into a display tank, sold, or traded through local frag swaps and online communities, both of which have become a significant and social part of how many hobbyists build out their collections over time.
Common Misconception
A common misconception is that fragging harms or stresses the parent colony significantly. When done correctly on a healthy coral, fragging causes only minor, temporary stress, and the parent colony typically continues growing normally, often healing over the cut site within days.
The Bottom Line
A coral frag is a small, propagated piece of a coral colony capable of growing into its own independent colony over time. Fragging underpins much of the modern reef hobby, enabling sustainable coral sharing and trading while reducing pressure on wild reef populations.
