Soda ash is the common name for sodium carbonate (Na2CO3). It is a weak base that is soluble in water and dissociates into sodium (Na) and carbonate (CO3) ions in solution.

Calcium is present in many makeup waters and formations. It can cause flocculation of the mud, resulting in increased rheology, gel strengths, and fluid loss. High-filtrate calcium causes precipitation of calcium-sensitive additives, such as POLY-PLUS high-molecular-weight liquid clay inhibitors and RINGFREE polymeric thinners, which are the most sensitive. Cellulosic polymers are only slightly calcium-sensitive and tolerate moderate levels of filtrate calcium.