The use of water of high electrical conductivity has become common in hydroponic systems, especially in regions with water scarcity. However, the use of inferior-quality water can affect crop yields. In this scenario, some studies have tested the use of chemical conditioning agents such as hydrogen peroxide to minimize the negative effects of stress on plants. From this perspective, this study aimed to evaluate the action of priming with hydrogen peroxide as a salt stress attenuator on the nutrient solution uptake and productivity of chives in a hydroponic system. The study was conducted in a protected environment with a randomized block design with a split-plot arrangement. The treatments consisted of a main plot consisting of the electrical conductivity of the nutrient solution (1.0, 2.0, 3.0, 4.0, and 5.0 dSm−1) and a subplot with five hydrogen peroxide concentrations (0.0, 0.15, 0.30, 0.45, and 0.60 mM). The increase in the electrical conductivity of the nutrient solution reduced bulb length, the solution volume applied, water uptake, total fresh mass, and the solution use efficiency by plants. Throughout the cultivation cycle in the hydroponic system, the consumption of nutrient solution was 459 mm lost by evapotranspiration. Acclimation with 0.60 mM hydrogen peroxide associated with 1 dSm−1 of electrical conductivity of the nutrient solution favors bulb diameter in chives. The increase in electrical conductivity compromises the productive yield of chives.