Very effective in the treatment of ich/whitespot. Toxic in overdoes. Not safe with sensitive fish such as tetras etc. Treat on day 1 and half dose (1ml per 40L) again on the 3rd day, monitor fish closely during treatment. Remove activated carbon from filter during treatment, replace with new carbon once dosing is complete. 1 ml per 20L (Half Dose 2ml per 40L) Please note this cure may damage live plants and stain aquarium silicone.