This research explored using ground oyster shells as a supplement to improve oyster mushroom cultivation. The study found that adding small amounts of oyster shell powder to the growing medium enhanced mushroom growth, yield, and nutritional content. This has practical implications for sustainable agriculture and food production. Impacts on everyday life: • Provides a way to recycle waste oyster shells into valuable agricultural supplements • Helps produce more nutritious mushrooms for consumers • Offers mushroom farmers an affordable way to improve their yields • Demonstrates sustainable practices by converting waste into useful products • Could help make mushroom cultivation more economically viable for small-scale farmers