Sizing library
Water system sizing examples
Useful long-tail reference tables for household size, hardness and bathroom flow.
By household size
Water Softener Size for 1 PersonPlanning table for a 1-person household across common hardness levels, using 75 gallons of softened water per person per day.Water Softener Size for 2 PeoplePlanning table for a 2-person household across common hardness levels, using 75 gallons of softened water per person per day.Water Softener Size for 3 PeoplePlanning table for a 3-person household across common hardness levels, using 75 gallons of softened water per person per day.Water Softener Size for 4 PeoplePlanning table for a 4-person household across common hardness levels, using 75 gallons of softened water per person per day.Water Softener Size for 5 PeoplePlanning table for a 5-person household across common hardness levels, using 75 gallons of softened water per person per day.Water Softener Size for 6 PeoplePlanning table for a 6-person household across common hardness levels, using 75 gallons of softened water per person per day.
By hardness
5 GPG Hard Water: What Size Softener?Planning table for 5 grains per gallon (about 86 mg/L as CaCO₃) across household sizes.10 GPG Hard Water: What Size Softener?Planning table for 10 grains per gallon (about 171 mg/L as CaCO₃) across household sizes.15 GPG Hard Water: What Size Softener?Planning table for 15 grains per gallon (about 256 mg/L as CaCO₃) across household sizes.20 GPG Hard Water: What Size Softener?Planning table for 20 grains per gallon (about 342 mg/L as CaCO₃) across household sizes.25 GPG Hard Water: What Size Softener?Planning table for 25 grains per gallon (about 428 mg/L as CaCO₃) across household sizes.30 GPG Hard Water: What Size Softener?Planning table for 30 grains per gallon (about 513 mg/L as CaCO₃) across household sizes.40 GPG Hard Water: What Size Softener?Planning table for 40 grains per gallon (about 684 mg/L as CaCO₃) across household sizes.
By bathroom count
Whole-House Filter Flow for a 1-Bathroom HomeA practical 7 GPM starting target for a 1-bathroom home, plus a fixture-based method to refine the number.Whole-House Filter Flow for a 2-Bathroom HomeA practical 9 GPM starting target for a 2-bathroom home, plus a fixture-based method to refine the number.Whole-House Filter Flow for a 3-Bathroom HomeA practical 12 GPM starting target for a 3-bathroom home, plus a fixture-based method to refine the number.Whole-House Filter Flow for a 4-Bathroom HomeA practical 15 GPM starting target for a 4-bathroom home, plus a fixture-based method to refine the number.Whole-House Filter Flow for a 5-Bathroom HomeA practical 18 GPM starting target for a 5-bathroom home, plus a fixture-based method to refine the number.