Reducing the formation of inorganic deposits in processing industrial waters presents a challenge for desalination systems. Our topic of research progresses the understanding of scaling phenomena in seawater and the effects of green inhibitors. In order to understand the processes occurring at the liquid-surface interface, a procedure has been developed to follow in situ and in real-time the growth of scale particles in the micrometer size range and to quantify the effects of inhibitor on the crystal evolution. Experiments were carried out with a green additive, polymaleic acid, at a concentration of 1 and 4 ppm and with PPCA (commercial phosphonate inhibitor) used as inhibitor reference. On the one hand, results showed that polymaleic acid reduces the formation of scale by acting on the nucleation and growth process namely at a concentration of 4 ppm. In this paper a comprehensive description of the inhibitor/ surface interactions will be presented. The role of the green additive in affecting the interface will be discussed in relation to the principal mechanisms by which the inhibitors function.