Fragging is how the reef hobby propagates - turning one colony into many specimens that get traded, sold, or distributed to other tanks. Done correctly, fragging accelerates growth (the colony rebuilds faster than the parent grew) and produces consistent revenue for vendors. Done poorly, fragging triggers RTN, infection, and parent-colony loss.
The technique varies by coral type. SPS frags from healthy colony tips. LPS frags by skeletal cuts that include polyp heads. Soft coral propagates from tissue cuttings.
For SPS: Dremel with diamond cutting wheel ($40-80), reef-safe cyanoacrylate gel ($8), frag plugs or rubble pieces, gloves and eye protection. For LPS: bone saw or coral saw with flush guard ($25-60). For soft coral: razor blades, rubber bands, fishing line.
Remove the colony to a separate cutting tray with display tank water. Cutting in-display contaminates the system with coral mucus and tissue debris. Have a freshwater rinse bath ready in case of bleeding.
Cut just below a branching point with the diamond wheel. Frag size: 1-2 inches with at least 2-3 healthy growth tips. Avoid cutting through the basal encrustation - the parent colony recovers faster from clean tip cuts than from base cuts.
Hammer/torch/frogspawn (Euphyllia): cut through the corallite branch, leaving 1-2 inches of branch and the polyp head intact. Acanthastrea / lobophyllia: separate individual polyp heads with a coral saw. Trachyphyllia: don't frag - the species doesn't respond well.
Leathers (Sarcophyton, Sinularia): take a 1-inch cap cutting, secure with rubber band to a piece of rubble. New tissue covers the rubble within 2-3 weeks. Zoanthids: cut through the mat with a razor (wear gloves - palytoxin). Mushrooms: cut the cap or foot in half - both halves regenerate.
SPS: cyanoacrylate gel on the frag base, press firmly onto a frag plug or rubble. Hold for 30 seconds. LPS: same method. Soft coral: rubber band to rubble (no glue - tissue regenerates over the rubble).
Place fresh frags in a low-flow, moderate-light spot for 2-3 weeks until cut sites encrust and tissue grows over the wound. Then move to final placement.
For SPS or LPS that bleed mucus or tissue heavily during cutting, dip the frag in a 5-10 minute iodine bath (Lugol's solution at 5 drops per liter) to prevent infection.