The study was conducted to find out the suitable concentration of egg shell powder for maximum growth of Spirulina platensis. In this work, Kosaric medium (KM) were used as control media while three different eggshell powder medium (ESPM) concentrations (25, 50, and 75%) were used to assess Spirulina platensis growth and culture performance. For a period of 20 days, each experiment was carried out in triplicates under fluorescent lighting in a situation of light: dark (12 : 12h). Every other day, measurements of the S. platensis treatments' cell weight and chlorophyll concentration were made. S. platensis was cultivated in KM media with eggshell in place of NaHCO₃, and the growth rate varied. The initial cell weight was 1.89mg/ L, reaching a maximum cell weight grown in KM, and 0.036 to 0.245mg/ L in medium contained 75% NaHCO₃ and 25% eggshell powder, 0.0042 to 0.0242g/ L in medium contained 50% NaHCO₃ and 50% egg shell powder, and 0.0039 to 0.033mg/ L in medium contained 25% NaHCO₃ and 75% egg shell powder. At the 16^th day of growth, the S. platensis had a chlorophyll a content of 0.034mg/ L, which had increased to 1.983mg/ L when grown in KM and 0.415mg/ L in medium made up of 75% NaHCO₃ and 25% egg shell powder. When compared to conventional KM, this medium concentration produced results that were satisfactory. This fluctuation in nutrient contents and the amount of egg shell powder likely resulted from variations in the nature of the medium. Therefore, it is inferred that the medium concentration that substituted 25% egg shell powder for NaHCO₃ is appropriate and beneficial for the growth of S. platensis.