Whole-House Water Filtration Systems

Why this matters

Whole-house water filtration is one of the highest-ticket plumbing add-ons - + install + /year recurring service. The customer concern: city water has chlorine + chloramine + sediment + occasional trace contaminants; well water has iron, manganese, hardness, sulfur, sometimes coliform. Bottled water doesn't solve shower + laundry + cooking exposure. The whole-house solution does - IF designed for the customer's water source + contaminant profile. Generic "one-size" systems disappoint; properly-sized + sequenced systems deliver durable customer satisfaction + recurring filter revenue.

Water testing - the design step

Before quoting any filtration:

City water: free Consumer Confidence Report from the utility lists treated contaminants. Common concerns: chlorine, chloramine, trihalomethanes, sometimes lead from premises plumbing.

Well water: customer-paid test at state lab OR certified water lab:

• Basic: pH, hardness, iron, manganese, TDS, sulfate
• Bacterial: coliform, e. coli
• Advanced: arsenic, radium, nitrate, lead, pesticides
• Test annually for well; every 5 yr for city

Visual + customer report:

• Sediment in faucet aerator → install sediment filter
• Hard water (white scale on faucets, soap won't lather) → softener or TAC
• Reddish stains on fixtures → iron + manganese (water treatment)
• Sulfur smell → H2S
• Chlorine smell → activated carbon
• Cloudy water → sediment, turbidity, OR air

Quote = filtration matched to test results, not a generic package.

System architecture

A sequence of stages targets specific contaminants:

1. Sediment (5 - 50 micron pleated/string-wound): catches sand/silt/rust. Replace 3 - 12 months.
2. Activated carbon (GAC cartridge or backwash tank): removes chlorine, chloramine (catalytic), VOCs, taste/odor. Replace 6 - 18 mo or backwash quarterly.
3. Iron/manganese/H2S (well only): iron filter (greensand, Birm, AIO) + oxidation pre-stage. Solves orange staining + sulfur smell.
4. Softener (hard water): ion exchange; salt-regenerated every 7 - 14 days. See Salt-Free Alternatives for TAC option.
5. UV sterilization (well water, optional): 30 mJ/cm² deactivates bacteria + viruses; annual bulb.
6. RO (point-of-use at drinking tap typically): removes 95 - 99% TDS.

Typical configurations

City water light: sediment cartridge + activated carbon cartridge; cartridges 2 - 4x/year.

City water mid-range: sediment + backwashing carbon tank (1.0 - 2.0 cu ft media); annual change; 99%+ chlorine/chloramine removal.

City water premium: sediment + catalytic carbon tank + salt softener (if >7 grains hardness) + optional UV; 10-yr tank media life.

Well water basic: sediment + iron filter (if >0.3 mg/L) + softener (if >5 grains) + UV.

Well water complex: aeration oxidation + sediment + backwash iron/Mn + carbon + softener + UV + kitchen RO.

Specific contaminants: arsenic (ion exchange or Bayoxide E33/GFH), nitrate (ion exchange or POU RO), bacteria (chlorination + retention + carbon + UV), radon (aeration tank with vent).

Tank vs cartridge

Cartridge filters

• Lower upfront
• 1 - 10 GPM flow per stage
• Replace cartridges 2 - 4x/year
• Customer-DIY replacement
• Best for low-flow + light contamination

Backwashing tank

• Higher upfront
• 10 - 25 GPM flow capacity
• Backwash flushes media weekly OR per schedule
• Service annually
• Best for high flow OR heavy contamination

Most whole-house systems mix: sediment cartridge + activated carbon backwashing tank + softener tank, for example.

Sizing for flow

The system must handle peak simultaneous demand without pressure drop:

• 1-bathroom home: 8 - 10 GPM
• 2 - 3 bathroom home: 12 - 15 GPM
• 4+ bathroom home: 15 - 25 GPM
• Commercial: per fixture count

Each cartridge / tank rated for max flow without exceeding pressure drop spec. Undersized = low water pressure when multiple fixtures run.

Installation considerations

Location: cold-water inlet to house, after pressure regulator, before water heater + softener. Each tank/cartridge needs bypass valves (3-valve combo common). Backwash tanks need drain (1.5 - 4 GPM): floor drain, sump pump, or outdoors (varies by jurisdiction). Backwash controllers + UV need 120V GFCI. Include test ports pre + post each stage. Sediment-stripper valve before whole system for post-install flush.

Service schedule

Cartridge change 3 - 12 months per stage (customer-DIY or plumber). Salt refill 3 - 8 weeks. UV bulb + sleeve cleaning annual. Annual whole-system service: water test at multiple points, cartridges, backwash controller verification, salt check, UV assessment.

Customer education

The "why" conversation:

• "Chlorine in your shower water vaporizes - you're inhaling it"
• "Hard water doesn't make you sick but it does shorten the life of every appliance + fixture in your house by 30 - 50%"
• "The water from your kitchen tap travels through 30 ft of plumbing in your house - that's where most lead exposure happens, not at the utility"

Personalize to the customer's specific concerns + test results. Customers with general "I want clean water" get a generic system; customers with named concerns get a fitted system + buy it.

Common mistakes

Generic system without testing: customer ends up with iron filter on water that doesn't have iron, OR no softener on hard water. Wasted equipment.

Undersized flow: 8 GPM system on 4-bathroom home; pressure drops with multiple fixtures.

No bypass valves: service requires shutting whole house off.

Skipping pre-sediment filter: media in downstream tanks clogs fast without sediment removal upstream.

Forgetting backwash drain: tank installed but no drain path → water damage.

Wrong tank-mount for water hammer: rigid mounting transmits shock to plumbing.

References

• NSF / ANSI 42 (Aesthetic Effects - Chlorine, Taste)
• NSF / ANSI 53 (Health Effects - Lead, VOCs, Cyst Reduction)
• NSF / ANSI 44 (Cation Exchange Water Softeners)
• NSF / ANSI 55 (Ultraviolet Microbiological)
• EPA Drinking Water Standards
• Manuall internal: Water Quality Treatment, Salt-Free Water Treatment Alternatives, Well Water Systems