Seachem Acid Buffer is a non-phosphate buffer for lowering pH in freshwater aquariums. Used alone, it reduces pH. When paired with Seachem Alkaline Buffer, it provides stable buffering for planted tanks or very hard water without adding phosphates. As it lowers pH, it converts carbonate alkalinity (KH) into available CO2. It is designed for planted aquaria or for very hard water where phosphate buffers may pose an algae or cloudiness problem. To lower pH, use 1/4 teaspoon (2g) for every 80 L (20 US gallons).