In this study, the effects of increasing dietary mineral levels of 0%, 50%, and 100% relative to the concentrations typically used to meet plant requirements in a standard hydroponic system on growth indices, waterborne and gut microflora of Nile tilapia (Oreochromis niloticus) were investigated within a recirculating aquaculture system. A total of 180 Tilapia, with an average weight of 30 ± 3.8 g, were distributed across nine experimental units (comprising three treatments and three replicates). The use of different levels of minerals in the diet had a significant effect on final weight, feed conversion ratio, weight gain, condition factor, and specific growth rate compared to the control group during the experimental period (p<0.05). The best results regarding the improvement of feed conversion ratio, weight gain, and specific growth rate were observed in Treatment 3 (100% dietary nutrients). The inclusion of nutrients significantly reduced the feed conversion ratio, with the highest ratio observed in the control group (p<0.05). As the dietary nutrient level increased, the condition index rose, and the lowest value recorded in the control group. Electrical conductivity and total dissolved solids were higher in the treatment containing 50% [supplementation] compared to the other two treatments. Supplementing the diet with minerals significantly increased the total intestinal bacterial count at the 50% level (p<0.05). Increasing dietary minerals to the 50% level negatively affected the number of bacteria in the fish's gastrointestinal tract. The results of this study demonstrated that increasing minerals at high levels, using the ratios applied in this trial, did not negatively affect the growth of tilapia.