Aquaculture is the fastest-growing sector of animal food production worldwide. However, many challenges face aquaculture farms, with two of the most critical being the high costs of production and the prevalence of diseases, which cause significant mortality, especially during the summer months. This study evaluated the effects of adding a commercial probiotic as a water additive for the Nile tilapia (Oreochromis niloticus) raised in semi-intensive earthen pond systems. The experiment was designed as a field study conducted on farms in various governorates. Four farms were selected, each with eight 2.5-acre ponds. Four ponds were treated with probiotics (W/Pro), while the other four served as control ponds without probiotic addition (W/OPro). On each farm, two ponds were used: one for probiotic addition (W/Pro) and the other as a control (W/OPro). Each pond was stocked with 12,000 fingerlings (5 grams each) per acre. The commercial probiotic (Aqua StarĀ®) was added to the experimental ponds at a rate of 200 grams per acre every two weeks for 180 days. At the end of the evaluation, total ammonia nitrogen (TAN), unionized ammonia (NH3), and nitrite (NO2) levels were significantly (P< 0.05) reduced in the W/Pro ponds compared to the W/OPro ponds. However, total dissolved solids (TDS), pH, and dissolved oxygen (DO) showed no significant differences (P< 0.05) between the two groups. Growth parameters such as final weight, weight gain, daily weight gain, specific growth rate (SGR), total length, standard length, and condition factor were significantly (P< 0.05) improved in the W/Pro ponds. Pond productivity per acre and survival rates were also significantly (P< 0.05) higher in the W/Pro ponds compared to the W/OPro ponds. However, there were no significant differences (P< 0.05) in feed conversion ratio (FCR), protein efficiency ratio (PER), or feed efficiency between the two groups. In conclusion, this study demonstrated that the use of probiotics in semi-intensive aquaculture systems for the Nile tilapia offers significant benefits, including improved water quality, growth performance, body measurements, pond productivity, and survival rates.