Environmental pH is one of the factors contributing to abiotic stress which in turn influences the growthand development of macroalgae. This study was conducted in order to assess the growth and physio-logical changes in Kappaphycus alvarezii under different pH conditions: pHs 6, ∼8.4 (control) and 9. K.alvarezii explants exhibited a difference in the daily growth rate (DGR) among the differe…