3-person household — by hardness
Modeled entry and mid‑tier ion‑exchange totals for a 3-person home. Totals scale salt and operating costs by household size relative to a typical 4‑person home.
3-person household at a glance
A 3-person home uses about 116 gallons of indoor water a day. Pick your hardness band for the full breakdown.
| Hardness band | Suggested size (grains) | Salt/month (entry) | Entry 5-yr | Mid-tier 5-yr |
|---|---|---|---|---|
| Soft (0–3.5 gpg) | 24k | 15 lb | $1,457 | $2,488 |
| Moderately hard (3.5–7 gpg) | 24k | 23 lb | $1,564 | $2,584 |
| Hard (7–10.5 gpg) | 24k | 30 lb | $1,671 | $2,680 |
| Very hard (10.5+ gpg) | 24k | 45 lb | $1,885 | $2,873 |
Other household sizes: 2-person · 4-person · 5-person
See also: all household sizes · by hardness band