Variations in Earth's rotation are caused by geophysical processes such as gravitational forces and mass redistribution in the atmosphere, oceans, hydrosphere, and cryosphere. To study these effects, scientists analyze four components of effective angular momentum: atmospheric (AAM), oceanic (OAM), hydrological (HAM), and cryospheric (CAM). HAM reflects hydrospheric mass changes and can be estimated using hydrological models or satellite data. Missions like GRACE and GRACE-FO have provided valuable HAM data since 2002, but gaps and limited time coverage restrict their effectiveness. Hybrid methods combining GRACE and Satellite Laser Ranging (SLR) improve estimates, especially for short-term variability. This study recalculates HAM using SLR-derived geopotential coefficients (C21, S21) from 1992 to the present, allowing analysis of long-term trends. It also introduces new hybrid solutions that use empirical orthogonal functions from GRACE fitted to SLR data, replacing standard spherical harmonics. These results, based on SLR and DORIS satellite data, are compared to hydrological models and validated against geodetic excitation (GAO) data. Comparisons across frequency bands, especially for periods over three years, show strong agreement, with correlation coefficients up to 0.9 for long-term, non-seasonal variations.