Argentum 200 50ppm colloidal silver, aerosol tonic - a tonic with high (50 ppm) colloidal silver content, based on demineralized water, ideal for acne skin prone to sebum overproduction.Argentum 200 50ppm colloidal silver, aerosol tonic - a tonic with high (50 ppm) colloidal silver content, based on demineralized water, ideal for acne skin prone to sebum overproduction.