- 1 Test
- 2 Read results
- 3 Treat
Putting a whole-house system together
Most wells need more than one stage. The order matters: each stage protects the next one. Here is the sequence, how to size it, and what it costs.
The order of stages
Water flows from the well through each stage in this order. You only need the stages your test calls for.
No single agency publishes one universal sequence. This one combines the rules that extension services and state health departments give for each stage.
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1
1. Sediment filter
Catches sand, silt and clay ahead of the softener, RO and UV. UV may need pre-filtering above 1 NTU (Minnesota) or 5 NTU (Ohio).1, 2, 5, 6
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2
2. Acid neutralizer (calcite) or soda-ash feed
Oxidizing media such as Birm need pH 6.8 or more. A neutralizer adds hardness, so a softener may also be needed.3, 5, 10
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3
3. Oxidation + filtration (iron, manganese, sulfur)
Turns dissolved metals into particles the filter can catch. Chlorine needs contact time, and often a filter after it.4, 5
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4
4. Carbon, after any chlorine
Removes leftover chlorine taste and odor.5
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5
5. Softener
Oxidized iron must be removed before it, because it fouls the resin.3, 6
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6
6. UV, last
"Typically the last device"; it needs clear, low-iron, low-hardness water to work.2, 5
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7
7. Reverse osmosis at the kitchen tap
For contaminants that matter when you drink them (nitrate, arsenic, PFAS).1
Size it for your peak flow
Every whole-house stage has to keep up with your home's peak demand. Nebraska Extension's planning minimums:7
Backwashing needs water too: about 10 GPM for a filter backwash and 5 GPM for a softener regeneration. Make sure your well pump can deliver it.7
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10 GPM
2 bedrooms / 2 baths
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12 GPM
3 bedrooms / 2 baths
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16 GPM
4 bedrooms / 3 baths
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17 GPM
5 bedrooms / 3 baths
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+2 GPM
Each extra bedroom or bath
What each stage costs
Minnesota's health department published these ranges from 2017 quotes and 2018 research. Low end DIY, high end professionally installed.1
Treat these as minimums. Prices have risen since 2017, so read every range as the least you'd pay today.
| Treatment | Whole house (initial) | One tap (initial) | Upkeep |
|---|---|---|---|
| Water softener | $200–3,000 | — | $50–300/yr salt |
| Oxidizing media filter | $1,500–3,000 | — | Backwash water, media |
| Aeration + filter | $800–4,000 | — | Backwash water, media |
| Continuous chlorination + filter | $500–2,500 | — | Bleach, media |
| Activated carbon | $500–3,000 | $10–100 | Filter changes |
| Adsorptive media (arsenic) | $2,400–4,500 | $300–700 | $700–900/yr whole house |
| Reverse osmosis | $5,000–12,000 | $300–1,500 | $100–200 every 1–2 yrs at the tap |
| UV | $250–800 | $150–300 | About $100/yr |
For current brand prices, see our reviews. Penn State Extension's buying tips: get written proof of NSF or WQA certification, and confirm any salesperson's test with an independent lab.8
Ready to choose? Next steps
Sources (10) · checked Oct 31, 2026
- Minnesota Dept. of Health: Minnesota Dept. of Health, Home Water Treatment fact sheet (rev. 2024-03-29; checked 2026-10-31)
- Ohio Dept. of Health: Ohio Dept. of Health, UV Light for Continuous Disinfection (rev. July 2011; checked 2026-10-31)
- Penn State Extension: Penn State Ext., Iron and Manganese in Private Water Systems (2025-05-29; checked 2026-10-31)
- Penn State Extension: Penn State Ext., Hydrogen Sulfide in Water Wells (2024-12-10; checked 2026-10-31)
- Virginia Cooperative Extension: Virginia Tech/VCE 442-670, Household Water Treatment (2024-10-22; checked 2026-10-31)
- Penn State Extension: Penn State Ext., Water Softening (2025-09-08; checked 2026-10-31)
- Nebraska Extension: Univ. Nebraska–Lincoln G2149, Planning for Water Use (May 2012; checked 2026-10-31)
- Penn State Extension: Penn State Ext., Tips for Buying Water Treatment Equipment (2026-07-01; checked 2026-10-31)
- CDC: CDC, Guidelines for Testing Well Water (2024-07-01; checked 2026-10-31)
- Connecticut DPH: Connecticut DPH, Publication 18: pH-Acidity of Private Wells (May 2009; checked 2026-10-31)