A 45- day study investigated the effect of magnetized water on improving the larval aquaculture of the European sea bass in deteriorated conditions.  The present study addressed the impact of magnetized water on growth performance, body proximate composition, oxidative stress indicators, water properties, and microbiota at the early larval stages. The larvae were stocked into fiberglass tanks. Four magnetic devices with different intensities in Tesla [T1 (0.015 T), T2 (0.035 T) and T3 (0. 050 T)] were manually prepared and applied in triplicates in addition to a control tank (no magnet). The results proved the suitability of using the strength of 0.035T for attaining better survival, and growth performance parameters that were significantly (P>0.01) surging the other investigated factors compared to the control. Meanwhile, this magnet dose (0.035 T) showed significantly higher crude protein content (CP%) as well as higher antioxidative activity in superoxide dismutase and catalase levels. Otherwise, microbial analysis of the different magnetized waters and the larval body showed varied counts. Thus, it was concluded that the exposure and intensity of 0.035T gave different bio-responses on the level of improving larval aquaculture and have varied physico-chemical-response with respect to water quality.