Temperature (High Acyl): Hydrates at 185°F/85°C, Gels from 158-176°F/70-80°C, Melts from 160-167°F/71-75°C
Temperature (Low Acyl): Hydrates between 167-203°F/75-95°C, Gels from 50-122°F/10-50°C, Melts from 176-284°F/80-140°C
The reason the temperatures vary is because the exact temperature will depend on concentration of Gellan used.