This study aimed to optimize hydroponic water spinach (Ipomoea aquatica) production through seed treatment, hydroponic and substrate cultivation systems comparison, cultivar selection, and photoperiod/daily light integral (DLI) evaluation. Seed treatment enhanced germination speed without significantly affecting the final germination percentage. All water spinach cultivars grown in deep water culture (DWC) systems showed significantly better growth performance compared to soilless substrate cultivation, with significant increases in fresh weight, dry weight, growth index ((height + width)/2), stem width and node number, demonstrating its superior efficiency for water spinach production. In the photoperiod experiment, three cultivars—Big Leaf, Small Leaf, and Super Bud—were exposed to five photoperiods (8, 12, 16, 20 and 24 hours/day) with fixed output light emitting diodes resulting in DLIs of 4.5, 6.7, 8.9, 11.2, and 13.4 mol·m⁻²·d⁻¹ respectively. Photoperiod/DLI had a significant effect on fresh weight, dry weight, and growth index stem width and node number, while cultivar only showed significant impact on node number, and a significant interaction effect on growth index was observed. Big Leaf and Small Leaf performed best under 20 hours/day (DLI=11.2 mol·m⁻²·d⁻¹), while Super Bud achieved its highest growth under 24 hours/day (DLI=13.4 mol·m⁻²·d⁻¹), showing greater light requirements. This study highlights the combined importance of photoperiod, cultivar selection, and seed treatment in optimizing hydroponic water spinach production.