Spirulina platensis is blue-green microalgae and well known due to its unique nutritional quality that has attracted a great deal of popularity in health products. In this research study, the culture medium uses BG11, SKM and MKM. All these alternative medium recipes are widely used and reported online. However, the suitability of the medium depending on the environment and the strain used. This study will analyses their effect on S. platensis by using growth parameters and determining the best culture medium for extensive cultivation. The optical density (OD) is one of the most critical parameters in Spirulina cultivation and recorded to measure the growth performance of S. platensis. In this study, the cultivation was conducted in 1 L conical flasks. The growth rate of S. platensis in the culture mediums observed for ten days of cultivation. Besides that, the initial pH also was recorded and monitored. The growth estimation by optical density was measured by using a spectrophotometer at 620 nm wavelength. The finding shows that MKM is the most suitable culture medium for cultivating S. platensis due to the best element compositions. The results showed the alternative low-cost culture medium, which was MKM, had been successfully formulated to cultivate S. platensis.