The impacts of environmental conditions (temperature, salinity, and nutrients) on growth, semi-refined carrageenan yield, gel strengths, viscosity were assessed the red seaweed Kappaphycus alvarezii in laboratory culture. Results showed that K. had a higher daily growth rate (0.94% day-1) at temperature (30 °C). Its yield was high (75.79%) combination low salinity (25 ppt) Conversely, strengths...