The AquaHeat Gas-Fired Heating System is a highly efficient way to heat your aquaponic or hydroponic system. Runs on natural gas or off-grid propane. Have you been searching for a way to keep your fish warm and happy without taxing your electricity? Are you looking for an aquaponic heating system with off-grid capabilities? AquaHeat is the latest in efficient natural gas or propane-fired heating for your aquaponic system.