This study was conducted in the Fish laboratory at Poultry and Fish Department, Faculty of Agriculture, Menoufia University. It was consisted of two experiments to evaluate the effect of some feed additives included natural zeolite supplemented  in the diets (first experiment) and some herbal additives such as fenugreek, rosemary, thyme and fennel in the diets (second experiment) for mono-sex Nile tilapia reared in hapas under the intensive system on growth and performance to improve diet quality and increase the production of fish farm with decreasing the cost. The initial weight of fish was (1.75±0.01 g) and were divided randomly in 18 hapas (1.5 × 0.5 × 1.0 m³) located in six concrete tanks (2 × 2 × 1 m³) under two levels of stocking density (20 and 40 fries/hapa). Three replicates for each dietary treatment were fed one of three experimental diets three times per day, six days per week for 12 weeks. The experimental diets were formulated to be similar in crude protein (30.8 ± 0.2%) and crude lipids (5.04 ± 0.06%). The diets are defined as CTRL, Z15 and Z30.The obtained results showed significant interaction between zeolite level and stocking density for temperature, dissolved oxygen, pH and ammonia concentrations in water, also a significant increase in final body weight was found when fish fed diet supplemented with high level zeolite (30 g/kg diet) under high density (40 fish/hapa) compared to other groups. Moreover, the interaction effect between dietary zeolite and stocking density showed that feed consumption did not differ significantly among all treatments except fish fed diets control and with 15 g/kg zeolite in the high density consumed the lowest feed, respectively. The second investigation was conducted to examine the inclusion of some herbal plants such as: fenugreek, rosemary, thyme and fennel at 10 g/kg diet on growth performance, feed utilization, body composition and ammonia excretion of mono-sex Nile tilapia reared in hapas. The average initial weight of the examined fish was (1.81±0.1 g) and distributed randomly in groups of 20 reared in hapas (1.5 × 0.5 × 1.0 m³) for 12 weeks.  Each dietary treatment was fed to three replicates that fed one of five diets three times per day (9.00 a.m., 11 a. m. and 1 p.m.). The obtained results indicated that fish fed thyme supplemented diet gained the highest final weight and fish fed rosemary supplemented diet gained the lowest value. In terms of specific growth rate (SGR %), fish fed thyme supplemented diet gained the highest value with significant differences (P<0.05) among all treatments. Also, Fish fed thyme supplemented diet showed the best feed conversion ratio (FCR) and significantly differed (P<0.05) among all treatments. It was showed that ammonia excretion rate in the water for fish fed rosemary and fenugreek supplemented diets were the lowest after 8 h with significant differences among all treatments. The supplementation of thyme at 10 g/kg diet improved the growth and feed utilization compared to other groups. No diet-related histopathological changes were noted in all examined tissues of the fish among all treatments in both experiments