Acid BufferÃ¢â€žÂ¢ is a non-phosphate buffer to lower pH and buffer with Alkaline BufferÃ¢â€žÂ¢. Both buffers are designed for the planted aquarium or for very hard water where phosphate buffers may pose an algae or cloudiness problem. Acid BufferÃ¢â€žÂ¢ lowers pH and buffers between 5.0 and 8.0 when used with Alkaline BufferÃ¢â€žÂ¢. As Acid BufferÃ¢â€žÂ¢ lowers pH it converts carbonate alkalinity (KH) into available CO2. It may also be used to safely lower pH in marine water.