**Abstract**

Fish has long been a source of "rich food for poor people" and has played an important role in increasing food security and nutrition in developing countries. Because various chemicals in algae can have confusing effects, the results of experimental research can be difficult to understand. Algae has been associated with strengthening immune systems, lipid metabolism, antiviral and antibacterial action, improved gut function, stress resistance besides providing a source of protein, amino acids, fatty acids, vitamins and minerals, and other biologically active phytochemicals in cattle and aquaculture feeds, even when used in modest amounts. The addition of algae to the fish diet modified the growth performance of the fish, causing it to improve. Its use resulted in a decrease in feed conversion ratio expenses, which plays an important part in determining aquaculture costs, an increase in feed efficiency ratio, and a decrease in feed conversion ratio. In accordance with the findings of chemical composition, various statements were acquired wherein the high proportion of algae significantly affects the protein and fat ratio. The outcomes demonstrated that algae could be a decent option as an additive for fish feed.

**Keywords:** microalgae, freshwater fish, health, growth
