Whole House Water Filtration Guide: Types, Systems & Costs

Why Filter Your Water

Municipal water meets EPA standards but can still contain chlorine, chloramines, lead (from old pipes), PFAS (forever chemicals), sediment, and other contaminants at levels below federal limits but above what many homeowners consider acceptable. Well water may contain bacteria, nitrates, iron, manganese, hydrogen sulfide (rotten egg smell), and hardness minerals. A whole house water filtration system treats water at the point of entry, delivering filtered water to every faucet, shower, and appliance in your home.

System Types

Sediment Filter

The first stage of any whole house system. Removes particulate matter — sand, silt, rust, and debris — that can damage appliances and clog other filters. Available in 5-micron (standard) and 1-micron (fine) cartridges. Replaced every 3–6 months.

Cost: $50–$200 for the housing. Replacement cartridges: $5–$20 each.

Carbon Filter

Activated carbon (coconite or catalytic) removes chlorine, chloramines, VOCs (volatile organic compounds), pesticides, herbicides, and improves taste and odor. The workhorse of residential water treatment. Available as replaceable cartridges or large tank-based systems with a media bed that lasts 5–10 years.

Cartridge-based: $100–$400 for the housing. Cartridges: $20–$60, replaced every 3–6 months.

1. Tank-based (backwashing): $800–$2,
2. 5
3. 0
4. Media lasts 5–10 years before replacement. Better for whole-house flow rates.

Water Softener

Removes hardness minerals (calcium and magnesium) through ion exchange. Hard water causes scale buildup in pipes and appliances, spots on dishes and glass, dry skin and hair, and reduced soap efficiency. A water softener uses salt (sodium chloride or potassium chloride) to regenerate the resin bed.

Signs of hard water: White chalky buildup on faucets and showerheads, spots on dishes, stiff laundry, soap doesn't lather well, scale in water heater.

Cost: $800–$2,500 for the unit. Salt: $5–$10 per 40-lb bag (use 1–2 bags/month).

Reverse Osmosis (RO)

Forces water through a semi-permeable membrane that removes 95–99% of dissolved contaminants including lead, fluoride, arsenic, nitrates, PFAS, and total dissolved solids (TDS). RO is the most thorough filtration method available for residential use.

Under-sink RO: Most common. Installs under the kitchen sink with a dedicated faucet for drinking/cooking water. 50–100 gallons/day. $150–$500.

Whole house RO: Treats all water entering the home. Requires a storage tank and repressurization pump. $1,500–$5,000+. Uncommon due to cost and water waste (RO systems waste 2–4 gallons for every 1 gallon produced).

UV Disinfection

Ultraviolet light kills bacteria, viruses, and other microorganisms. Essential for well water systems where biological contamination is a concern. Installed after filtration (the water must be clear for UV to work effectively). Bulb replacement annually ($50–$100).

Cost: $300–$800 installed.

Testing Your Water

Before choosing a system, test your water. Municipal water: request a copy of your utility's annual water quality report (Consumer Confidence Report). Well water: test annually for bacteria, nitrates, pH, and hardness. For comprehensive testing, send a sample to a certified lab ($50–$200 for a full panel).

Costs

Basic sediment + carbon (cartridge): $200–$600 installed.

Carbon tank system (backwashing): $1,000–$3,000 installed.

Water softener: $1,000–$3,000 installed.

Softener + carbon combo: $2,000–$5,000 installed.

Under-sink RO (drinking water): $200–$600 installed.

Annual maintenance (all systems): $50–$200 for filters, salt, and UV bulbs.