looked up my city's water company and they reported that the hardness is 13.5 grains per gallon.
When municipal water is obtained from multiple sources, they will most often state hardness as an average hardness number from all sources. As such, depending on your home"s location within the distribution system, the hardness of the water supplied to your home could be normally lower or higher than average. Because measuring hardness with a Hach 5B directly at your location, will provide a snapshot of the hardness at that specific time, recommend programming the softener's hardness setting for 2-3 gpg higher than the test result, to anticipate occasions that hardness maybe higher than normal. Hardness levels will often vary during times of high water consumption, fire hydrant use, or during distribution system maintenance or repair.
For a softener equipped with 1.5ft3 resin, to achieve the best balance of salt efficiency, soft water quality, and useable capacity, the usual recommendation will be to program the salt setting to 12 lbs (8 lbs/ft3), to regenerate 36,000 grains useable Capacity. These settings will result in a hardness reduction efficiency of 3,000 gr/lb (36,000 / 12 lbs), providing high quality soft water containing only 6ppm hardness.
For higher salt efficiency, 9 lbs salt {6 lbs/ft3) will regenerate 31,500 gr Capacity, thereby achieving 3,500gr/lb efficiency, but hardness leakage will be increased (lower quality soft water) to 10 ppm.
By programming the appropriate Reserve Capacity setting, that amount will be automatically calculated and subtracted from the gallons remaining shown in the controller's screen. No manual compensation calculation will be necessary.