Developing suitable materials for fish to prevent heavy metal pollution in water is a delicate topic in fish farming. The effect of adding Azolla and Duckweed to the diet of carp (Cyprinus carpio) and its involvement in coping with copper toxicity were studied in this study. In the experiment, carp (Cyprinus carpio) divided into 5 groups. The first group left untreated (negative control), second group as the positive control treated with copper sulfate CuSO₄ only at a concentration of (0.5 mg/L), the third group was treated with (0.5 mg/L) CuSO₄ with Azolla, the fourth group used CuSO₄ (0.5 mg/L) in duckweed plant water, while the fifth group used CuSO₄ (0.5 mg/L) in Azolla and duckweed mixture. The treatments lasted 56 days. Each group of treated fish had their overall clinical complaints assessed. At the end of the 56-day period, the fish from each group were autopsied. Alanine-aminotransferase (ALT), aspartate-aminotransferase (AST), urea, uric acid and creatinine levels were measured. The result reflected different clinical symptoms in common carp. The blood parameters revealed significant increase in the second group treated with copper sulfate and the significant decrease were in the fifth group. The degree of histopathological alterations and lesions of the liver and kidney differed depending on the Azolla-aquatic duckweed plant mixture treated with CuSO₄. According to this study, Azolla and duckweed can be utilized in fish diets to minimize the harmful effects of copper.