Marine Ich Treatment: Copper, Tank Transfer, and Hyposalinity Compared

Marine ich (Cryptocaryon irritans) is the most common parasite in saltwater aquariums. Three proven treatments work, but each has tradeoffs.

Copper therapy

Maintain 0.5 ppm chelated copper for 30 days in a quarantine tank. Most reliable, but invertebrate-toxic and stressful for some sensitive species.

Tank Transfer Method

Transfer fish to fresh sterile tanks every 72 hours for four cycles. Drug-free and effective but logistically demanding.

Hyposalinity

Drop salinity to 12 ppt for 30 days. Easier on fish than copper but only works at carefully measured salinity.