Four different exogenous factors: the strength of PES, commercial fertilizers/biostimulant, plant growth regulators, and salinity were studied to understand their effects on the growth of G. changii in vitro. Seaweed segments in approximately 5 mm (0.02 g) were used as explant materials for each experiment. Total of 5 explants were cultured in Fernbach culture vessel with 100 mL of medium for each experimental condition. The experiments were carried out in triplicate.