The study aimed to evaluate the efficacy of traditional gypsum, and gypsum particle diameters, independently and in conjunction with filter cake, in reclaiming saline-sodic soil. This assessment was conducted through a leaching experiment utilizing column technology, utilizing soil collected from the EL Abbasa region in Egypt's EL Sharkia Province. The results of the study indicated a significant decrease in electrical conductivity (EC), pH, and exchangeable sodium percentage (ESP), coupled with an increase in hydraulic conductivity (Ks), for all treatments—whether applied individually or in combination—when compared to the control. Notably, the combined treatments demonstrated a higher effectiveness level than individual applications. Furthermore, the study revealed that the fineness of gypsum particles plays a crucial role in reducing salinity and sodicity. Specifically, the use of fine gypsum particles (<63 μm) in conjunction with filter cake was found to enhance the reclamation process, resulting in more substantial reductions in salinity and sodicity in saline-sodic soil. These findings suggest that the strategic application of fine gypsum, particularly in combination with filter cake, can contribute significantly to soil reclamation efforts.