H20 Nuvo DPHB Home Salt Water Softener SystemWater flow: 12-15 gpm with 1-Inch ports (no change to existing flow)Capacity: about 50,000 gallons (average annual water usage of household of 2)Uses 20-Inch Salt-Free Replacement Cartridges, Eliminates existing damaging scaleOther products may prevent scale buildup but don't remove existing scale, No harmful salt avoid the hassle of constant salt replenishmentProtect your health and our environment from the harmful effects of salt used in other softeners