The interface of CaCO3 (calcite) and water is of paramount importance in a number of key academic and industrial areas, including scale deposition in domestic and industrial situations. Neutron reflection has proved to be an outstanding technique for the study of solid/liquid interfaces. In this proposal we aim to exploit the power of this technique to investigate the adsorption of a particular additive (fatty acids) at the calcite/liquid interface which has profound implications in several areas of interest.