Agricultural intensification in the El-Oued region, Algeria, has degraded irrigation water quality due to increasing salinity. This study aims to assess the effectiveness of Atriplex halimus seeds for phytopurification, specifically their ability to reduce electrical conductivity (as a proxy for salinity) in irrigation water. A comparative laboratory experiment was conducted using water collected from five representative boreholes in different zones of El-Oued, selected for varying initial salinity levels. The water was treated with Atriplex halimus seeds under controlled conditions, and electrical conductivity was monitored regularly over a range of contact times. The results demonstrate that Atriplex halimus seeds significantly reduce water salinity during the initial 1 to 6 hours of contact, with the most pronounced decreases observed at higher initial salinities. For example, an immediate reduction was recorded in several zones within 5 to 30 minutes. Stabilization of electrical conductivity occurred from 5 to 6 hours, after which further contact led to a secondary increase in salinity due to ion release from the seeds, indicating saturation. The optimal phytopurification window is therefore within the first 6 hours. Effectiveness is time-dependent and limited by seed saturation; extended exposure beyond 6 hours may reverse the purification effect due to physiological limits of the seeds and the subsequent release of ions. This method offers a cost-effective, sustainable means for reducing irrigation water salinity in arid regions, improving the viability of marginal lands for agriculture. The research is the first to characterize and quantify the phytopurification potential of Atriplex halimus seeds in the Saharan context, providing operational recommendations for treatment duration to optimize salinity reduction and avoid undesirable effects.