Acid Buffer is phosphate/carbonate free buffer for lowering and stabilizing pH in the acid range of pH 4-6.8. Acid Buffer is designed primarily for freshwater use, is ideal for planted aquaria, and may be substituted for Discus Buffer wherever phosphate buffers may pose a problem, such as in high calcium waters or aquaria prone to undesirable algae growth. It is compatible with Discus Buffer, Neutral Regulator, and Alkaline Buffer. It may be used to safely lower pH in marine water. A 250 g bottle treats 800 gallons. DIRECTIONS: For water changes use the chart below to set a target pH. Add this water to the tank within 6 hours to avoid pH fluctuations. Thereafter, to lower pH, use 1 measure (enclosed) to every 5-10 gallons daily until intended pH is reached. Add directly to aquarium. Usage in excess of the recommended dose may rapidly drop the pH too far. Larger doses may be required in very hard alkaline waters. Use Prime? for dechlorination and Alkaline Buffer? to raise pH. Caution! Corrosive! Aquarium Use Only! Keep Away from Children! Avoid contact: dry or concentrated product can be corrosive and irritating.