2-Gallon Salt Feed System. The LectraSan does not require a salt feed system for ocean water use as the salinity of the ocean water is sufficient to operate the system as designed. Salt can be added to the LectraSan using a 2-Gallon Salt Feed Tank for brackish water. Low salt is indicated on the LectraSan Control Indicator Panel.. Operation. A salt solution is mixed and placed in the salt feed tank. Every time the toilet is flushed, part of the salt water solution is mixed with incoming water to increase the water salinity in the Treatment Tank. The LectraSan Control Indicator Panel will show when the Salt Feed Tank needs to be refilled with more salt solution.