Water Purification Guide

A complete guide to choosing a water filtration system for your home — the types, the real costs, and what to look for.

Test your water first

Before buying any filter, test your water. On city water, request the free annual quality report from your utility. On well water, run a $50–150 lab test. Know what you’re filtering before you spend a dollar on equipment.

Types of filtration

Carbon: removes chlorine, taste, and odor — $20–100. Reverse osmosis: removes 95%+ of contaminants — $200–500. UV: kills bacteria and viruses — $100–300. Whole-house: treats all incoming water — $500–2,000.

What to remove

Chlorine (taste), lead (health), sediment (clarity), fluoride (debated), nitrates (well water), bacteria (well water), and PFAS (an emerging concern). Your test results decide your system — not a sales pitch.

Maintenance

Carbon filters: replace every 3–6 months ($20–40). RO membranes: every 2–3 years ($50–100). UV bulbs: annually ($30–80). Set calendar reminders — a neglected filter is worse than no filter at all.

Cost comparison

Bottled water runs about $1,400 a year for a family. An under-sink RO system is roughly $300 to install plus $80 a year. A whole-house system is about $1,500 installed plus $100 a year. Filtration pays for itself in months.