One hundred fish of red tilapia (O. niloticus X O. aureus) fingerlings averaging 7.33 ± 0.57g in weight, 10 fish / aquarium (40 x 70 x 60 cm). The pH levels tested were 2, 3, 5, 9 and the control (7.53) for a period of 30 days. When red tilapia subjected to water pH 2 treatment the fish were die out after 24 hours, but when red tilapia subjected to water pH 3 the fish were die out after 36 hours from the beginning of the experiment. The survival of fish subjected to water pH 9 was 95% and to water pH 5 (85%). The growth rate of fish at pH 5 (1.2±0.3) g/fish compared to the control group 2.0±0.40 g/fish, it was noted that the feed conversion ratio was less in water pH 5 and 9 treatments as compared to the control group. Analysis of the blood samples shows that significant differences (p ≤ 0.05) for red blood cells count and the hemoglobin values in fish subjected to water pH 9 treatments was very close to the control group. But the highest value in the analysis of serum urea was recorded at pH 5 however this treatment recorded minimum values in the analysis of serum uric acid, serum total protein and serum creatinine compared to the control group. The analysis of blood sugar shows significantly decrease in treatments pH 5 and 9 compared to the control group. Microscopic examination of histological sections in each of kidney and liver for fish was found that there had been light damage in these organs compared to the control group. This damage was reflected in the growth and productivity of these fish. We are recommend that red tilapia fingerlings cannot be cultured at pH levels of 2 or 3, where lead to deaths of these fish. Could farming of red tilapia fingerlings under the levels of acidity and alkalinity ranged between 5 to 9 without a significant effect on the productivity and physiological parameters of these fish.