What Size Water Softener Do I Need in Sacramento by Whole House Water Filtration System https://wholehousewaterfiltrationsyst... How to tell what size Water Softener I Need For A Family size of 1-2, 3-4, 5-6, 6-7? On average in the US, water use at home (water from the tap, toilet, dishwasher, etc.) adds up to about 138 gallons per household per day, or 60 gallons per person per day. *3 people (75 gallons per person per day) in a home avg. 225 gallons of water used per day with 15GPG will need a 32,000 grain system set up for 24,000 grain capacity. Home Water Filtration Systems Sacramento 75 Natoma St # C1, Folsom, CA 95630 855-835-3720