Use 1 capful (5 mL) for each 40 L (10 gallons*) on the first day with a new aquarium. Then use 1 capful for each 80 L (20 gallons*) daily for 7 days. Fish and other aquatic species may be introduced at any time as long as dosage is maintained for 7 days. For optimum biofilter performance use 1 capful for each 40 L (10 gallons*) once a month or with each water change and whenever introducing new fish or whenever medicating an aquarium.