RTN

Definition

RTN (Rapid Tissue Necrosis) is a coral disease where tissue sloughs off the skeleton over hours to days, typically affecting SPS coral. Often triggered by parameter swings (alk swing >1 dKH/24h), AEFW infestation, low DO, or bacterial infection.

Practical use in aquariums

Treatment: cut healthy tissue away from the necrotic edge with sharp shears, frag onto a clean plug, dip the salvaged frag, mount in moderate flow. Stabilize tank parameters first - new pieces will RTN again if the underlying cause is not addressed. Test alk swing with daily measurements for 7 days.

How RTN fits the bigger picture

Understanding RTN matters because it's connected to broader husbandry decisions: disease prevention is cheaper than treatment - quarantine + dipping protocols paid back the first time you avoid a tank-wide outbreak.

Browse the Fast Aquatics care library for full husbandry tutorials covering RTN in context.