Abstract <p>One of the major problems which the world faces today is water scarcity, as every life needs it for their day-to-day activity. Pollution and salinity are the two major causes of most waterbodies being unfit for use. Removing pollutants or salt from water became essential for overcoming the water shortage. Desalination technology is being used to achieve this, but the major disadvantage is its lower production. Applying solar energy and nanofluids may tackle the problem and increase the production. In this work, some physical and chemical parameters, in particular isoelectric point (pH), total dissolved solids (TDS), electric conductivity (EC), chloride (Cl^–), fluoride (F^–), iron(II) (Fe²⁺) content, were studied before and after desalination. Also, the influence of various water nanofluids (WNF) on increasing the output of glass-made double slope solar stills was studied. Physical and chemical parameter analysis revealed a reduction in values after desalination. Single and double-basin glass solar stills of 0.81 m² basin area were fabricated, and the experiments were conducted at Kovilpatti. The experiments were carried out at a depth of 1 cm with borewell saline water and nanofluids under insulated conditions. A maximum productivity of 4350 mL per 0.81 m²/day (5405 mL/m²/day) was obtained while using Al₂O₃ nanofluid in a double basin glass solar still, which was higher than that obtained using water, SnO₂ and ZnO WNF. This confirms the efficiency of Al₂O₃ aqueous nanofluid, which yielded more distillate than other two nanofluids used.</p>