If you’ve never had to purchase a water softener before, sizing for flow rate might be a little confusing. The best way to make sure you get the right flow rate for your home is to find a system that provides at least 2 gpm (gallons per minute) per member of your household.
If you’re confused about flow rate, contact the manufacturer. They can ask you about your family size and your water usage and suggest a flow rate based on your information.