CITRIC ACID is a source of hydrogen ions (H+) used to reduce the pH of a drilling fluid. Both liquid and powdered. CITRIC ACID provides a layer of hydrogen ions around active clays, reducing their zeta potential and thus reducing their ability to imbibe water. This function translates to fewer solids, less swelling of the solids in the drilling fluid, reduced wellbore swelling, and more efficient solids control equipment function. A secondary benefit of CITRIC ACID is the formation of sodium citrate, a thinner. This helps counteract the flocculating influence of the hydrogen ions on first being introduced to the drilling fluid system.