hi Al, first I thank you very much for your help, I done the treatment using levamisole for 24 hours, I notice that some fishes gill are open a little after WC. also I notice that the fishes look more colorful, but the are afraid and shy, I want to ask if I can add salt now to the tank to help the gill? also is it mandatory to repeat the levamesole treatments after 3 weeks or not ? thanks a lot my lord