Heart of the Sea - AelveMC/SEP_1_Renewables GitHub Wiki

Guardians near a conduit will begin draw draw power from the conduit and will begin glowing. After 100 second the guardian will convert to an Elder guardian.
Note: This does not need to be a consecutive 100 seconds. A guardian can exit and come back and continue converting from where it left off.

Elder Guardians no longer drop Wet Sponges. Instead, they have a 1/3 chance of dropping a Heart of the Sea.