Unicellular Dinoflagellate parasite. Not to be confused with Freshwater Oodinium or "Velvet".
Invariably fatal if not caught VERY EARLY. Highly contagious, can wipe out complete stock if not checked quickly.
To treat fish with copper, is the surest way to kill the parasites, but a VERY good test kit must be used, and it is essential to understand that in the beginning the free copper ions will bind with all kinds of matter in the Aquarium. Especially with live rocks and more, as well as the glass. It is most preferable to treat fish in a bare quarantine tank, and monitor for the first few days the level of copper in the tank, both before each new treatment, and after treatment, both 10 minutes later as well as an hour later to see if the copper level is where it should be (.25ppm) or if it has fallen away, and needs a 'top up'. Under no circumstances use copper in a tank with Invertebrates, as is invariably fatal to them even at low levels, as well as to algae on live rock.