Peca said:
Steve, I am also interested where you find data about Octozin and metronidazole?
Alot of googling and intuition
, I will see if I can find the references again.
And if it is metronidazole, wich stage of Oodinium or/and Cryptocarion they cure?
It won't, that's the problem. Metronidazole is a good treatment for internal problems (de worming) but is ineffective against these two, especially the Amyloodinium.
My aquarium is small, only 160 l (40 gallons), and have 5 fishes: 3 ocellaris, 1 Regal tang and 1 six line wrasse, some soft corals - sarcos and sinularias, some mushrooms, green star polyps, buttons... mainly low light demand animals.
I mean no offense but you have more fish than I do in my 90, very cramped especially for the tang. Once you get this sorted out, I would highly suggest finding the tang a larger home or upgrading your tank size.
I think that NO2 is trigger for whitespots. 10 days ago we have electrical failure and NO2 jump to 0,1. Right now it is 0,05.
No amount of stress or other water conditions can cause C. irritans to just happen. The parasite was either present in the tank to begin with or was recently introduced. Stress can lower the immune response of the fish leaving it open to attack and infestation faster than if it where in prime health but a healthy fish can get it just as easily. If the parasite is not present, no amount of stress will bring about this parasite.
What was the last item added (fish/coral/hard surface item) and how long ago? Just because a fish developes a spot on it's body does not automatically mean crypt so best to be sure.
If this is C. irritans, your best approach is to remove all the fish to a large enough QT. It doesn't need to a be a proper tank although being able to view the fish properly is a plus, a large rubbermaid tote will do. It doesn't need to look good, just be functional. If you have any bacterial mass that can be transfered that will help immensely. Something from the sump, canister filter or HOB. Biowheels work very well for this process. Along with that you will need a heater and powerhead if water flow is not optimum.
Follow the directions on this website. Pay special attention to salinity (14 ppt) and pH throughout the process, especially the pH during the initial drop. Using buffered RO water for the dilution will help minimize the pH drops. It is also not uncommon to need buffer to maintain pH/alk during the process. I would test at least 2x a day to be sure everything is in order. Please be sure to use a refractometer, not a hydrometer.
http://www.petsforum.com/personal/trevor-jones/hyposalinity.html
Cheers
Steve