What Size Water Softener Do I Need?
What Size Water Softener Do I Need?
Softener sizing is critical — too small and it regenerates too often; too large and it wastes salt and water. Here's how to get it right.
The Sizing Formula
Water softener capacity is measured in grains. To size a softener correctly:
Daily softening requirement = Number of people × Gallons per person per day × Water hardness (GPG)
Example: 4 people × 75 gallons/day × 20 GPG = 6,000 grains/day
A properly sized softener should regenerate every 3–7 days. Divide the daily requirement by the desired regeneration frequency to get the minimum capacity.
Example: 6,000 grains/day × 7 days = 42,000 grain capacity needed
Common Softener Sizes
- 24,000 grains: 1–2 people with moderately hard water
- 32,000 grains: 2–3 people with hard water
- 48,000 grains: 3–4 people with very hard water (common in Citrus County)
- 64,000 grains: 4–6 people with very hard water, or homes with iron
- 80,000+ grains: Large families or commercial applications
Iron Adds to the Requirement
If your water contains iron, add 5 GPG to your hardness number for every 1 mg/L of iron. Example: 20 GPG hardness + 3 mg/L iron = treat as 35 GPG for sizing purposes.
Let Aqua Logic Size It for You
Proper sizing requires knowing your actual water hardness and iron levels — not estimates. Aqua Logic tests your water and sizes the right system for your household. We don't upsell oversized equipment; we recommend what you actually need.
Have Questions About Your Water?
Schedule a free water test — we'll identify exactly what's in your water and recommend the right solution.