Need help with Water System

[Reach4]

Looking around for info; I think it should be 28 minutes for BF.

Using 60k softener capacity
20# of salt per regen
1 gallon to dissolve 3# of salt

~7gallons
7 gallons @ 0.25gpm = 28min

20/3/0.25=26.6666666666667 which rounds to 27.