Leaves biological filtration running. Switch off u.v. sterilisers, ozonisers and remove carbon before use. Contains colour dye, avoid contact with clothes and furnishings. Do not use in systems containing sharks, rays, Harlequin Tuskfish, algae, invertebrates, live rock or related species. In these instances use Octozin for protozoal infections. When using undergravel, internal or external power filtration use the standard dose. For all other filtration use half the stated dose. Half dose should be used in new aquaria or when fry are present. Do not use simultaneously with other medications. Allow at least 4 days to elapse and remove with activated carbon before changing treatments.