Boil one bag in 1 liter (1 US quart) of water for 10 minutes or until desired extract color is attained.  Let extract cool to aquarium temperature and pour the amount needed directly into the tank or mix with prepared water for water changes.  When first using extract, add gradually over a 2 to 3 days and monitor to ensure pH stays within suitable range for tank inhabitants. Alternatively, add 1 bag per 40L (10 US gallons) to an external filter such as a Seachem Tidal Filter for a time-release effect. Monitor pH and remove bags when the wanted level or amount of tinting is achieved. Chemical filtration media such as activated carbon can remove compounds provided by Catappa Tea Bags.