Salt Calculator for Industrial Water Softener – Zero Hardness The Industrial Water Softener Salt Use Calculator below can estimate how much money and salt you will save with our Zero Hardness Water Softener. 15 lb Salting 10 lb Salting 6 lb Salting INPUTS Total gallons processed per day (GPD): Salt cost per ton: Salt cost per pound: Grains of hardness as calcium carbonate (CaCO3): Grains of hardness (capacity per cubic foot): 15 lb Salting 10 lb Salting 6 lb Salting Total grains hardness removed per day: Cubic feet of resin to be regenerated per day: Salt used per day in lbs: Gallons of brine used per day: Salt used per day in tons: Salt used per Month in tons: