Whole-house sediment, carbon, or reverse osmosis—calculate the complete installed cost including filter housing, bypass valve, drain connection, and labor so your quote covers every fitting and union before the customer prices out the DIY kit at the hardware store.
A whole-house sediment filter needs its cartridge replaced every 3–6 months under normal conditions. A carbon block filter: 6–12 months. A reverse osmosis membrane: 2–3 years, pre/post filters annually. Homeowners forget. The filter gets clogged, pressure drops, the customer thinks something is wrong with the system, and they call a plumber — but not necessarily you. Build a filter replacement reminder into every installation: "I'll send you a reminder when your filter is due. We stock the replacement cartridges and can swap them during any service call in the area." This is 30 minutes of labor and a $15–$40 cartridge, billable at $75–$125 per visit. Five customers on a filter reminder program = 10–20 service calls per year with zero marketing cost.
Installing a filter without a bypass valve is a liability. When the filter housing needs servicing, the homeowner either has no water or has to shut off the main. With a 3-valve bypass (isolation valve before filter, isolation valve after filter, bypass valve in parallel), servicing is 30 seconds and the home has water throughout. The bypass also protects against filter housing failure — a split housing with no bypass floods the space. Material cost: $25–$45 in valves. Labor: 30–45 minutes. Present it on every quote as standard practice: "I always install a service bypass — it means you never lose water pressure while we're changing filters." Homeowners who've had a plumber leave them with no water during a service call know exactly why this matters.
Well water filtration is not the same as municipal water filtration. Iron bacteria, hydrogen sulfide, pH imbalance, hardness, and coliform contamination each require different treatment. A customer who calls about "bad-tasting water" from a well may have sulfur (H2S — distinct rotten-egg smell, requires aeration or oxidation filter), iron (red staining, metallic taste — requires iron filter or softener), or hardness (scale buildup — requires softener). Do not quote well water filtration without a water test. A $30–$50 water test kit sent to a lab, or an on-site test strip for common parameters, tells you what you're actually treating. Installing a carbon filter on a high-iron well does nothing — and you own the callback. Always test first, then specify the system. The test cost is billable, and the correct system sells for 30–50% more than a generic filter.
The Plumber's Business Starter Kit includes a flat-rate price book for 35 common plumbing jobs, service agreement template, and water quality reference guide. Guide from $19 — Complete Kit with all 19 templates, $49.
Get the Plumber's Kit →Whole-house filtration system pricing depends on system type (sediment, carbon, softener, RO), installation location, connection size, and whether bypass valves and pre-filters are included. This calculator builds a complete installation price from equipment markup, fittings, labor, and any water testing required — so you're pricing filtration jobs profitably, not just guessing at a number.