Use dosing cap on bottle. Shake well and add 1 ml per 2 gallons (7.6 L) or add 5 ml (1 tsp.) per 10 gallons (38 L) of aquarium water. For best results, add weekly and when doing a water change. For extremely dirty aquariums or vivariums, dosage may be doubled. Tip: always wash your hands after handling your pets or cleaning their aquarium/vivarium or decorations.