Applying magnetized water to marine aquaculture is still a new application, and studies are very scarce. Accordingly, our study was conducted on gilthead seabream, Sparusaurata, and juveniles to assess the impact of continuous exposure to magnetized treated water at various Tesla levels on water properties, as well as any subsequent consequences on juveniles' development, performance, and survival rate. A 60-day growth trial was carried out using magnetized treated water during the juvenile rearing period (from 60 to 120 days) with magnetized intensities corresponding to 0, 10, 40 and 60MT in the control, F₁, F₂ and F₃ treated groups, respectively. Each replicate treatment included 200 seabream juveniles. Determination of environmental factors, including water temperature, pH, salinity, and dissolved oxygen was carried out. The magnetization system was running around the clock. The findings showed that for 60 days, varying magnetic intensities had an impact on the survival rate of sea bream juveniles reared in magnetic water. At the end of the experiment, histopathological alterations were assessed between specimens of selected organs (intestine, liver, and kidney) collected from different fish juveniles treated groups. In this study, the magnetized water decreased bacterial load compared with the normal water (control) considering the antimicrobial efficacy of magnetized water.  Overall, it was concluded that exposure of sea bream juveniles to magnetized water of intensity corresponding to 40MT represented the highest survival rate (51.67%), improved its growth performance and water properties, reduced microbial infected communities, as well as restored the normal architecture of intestinal and renal tissues in a recirculating healthy aquaculture system.