Reverse Osmosis Cost by System Guide
The system priced by its form: countertop, under-sink with tank, tankless, and whole-house rows apart, by frame.
Orange County, CA · Updated 2026 · Costs shown as ranges — your quote will vary by installer and scope
The by-form readings, priced apart by frame
| System form | Frame A reading | Frame B reading |
|---|---|---|
| Countertop unit | $200-$700 | $200-$450 installed |
| Under-sink, with tank | under-sink row at $200-$800 | $300-$700 installed |
| Under-sink, tankless | $250-$900 | $450-$950 installed |
| Under-sink, all rows | $200-$800 | $300-$950 installed |
| Whole-house, point-of-entry | $1,000-$4,800 | $4,800-$8,000 installed |
Each reading is one frame's own counting of one form. No band is averaged across forms or across frames here: the countertop row is a point-of-use row, the whole-house row is a point-of-entry row, and the two are never read as one band.
The unit and installed rows, priced apart inside each form
| Form, Frame B | Unit row | Installed row |
|---|---|---|
| Under-sink, with tank | $150-$350 | $300-$700 |
| Under-sink, tankless | $300-$600 | $450-$950 |
| Whole-house, 500 gallons per day | $4,500-$6,500 | $4,800-$7,000 |
| Whole-house, 1,500 gallons per day | $5,500-$7,500 | $5,800-$8,000 |
| Unit prices, average across forms | $150-$600 | installed rows stand apart above |
Frame B prints its unit rows beside its installed rows inside each form, and a Culligan installed row at $1,050 to $1,700 beside them. Frame A prints no unit-versus-installed split by form; its rows stand beside an average installation of $2,200 and annual maintenance at $175 to $600.
The whole-house divergence, named on this page too
The two frames' whole-house bands diverge sharply: $1,000-$4,800 in Frame A against $4,800-$8,000 in Frame B. That divergence is named as a frame difference on every page here, never averaged and never blended into a single whole-house band. Frame A counts the whole-house form nationally beside its point-of-use rows; Frame B counts whole-house installed rows by unit size, from $4,800 to $7,000 at 500 gallons per day to $5,800 to $8,000 at 1,500 gallons per day. Each counting stands as printed, on its own rows.
Form rows priced apart, neighbours named apart
Named apart, never a row here: water softeners, the hardness machine for spots and scale; whole-house filtration, the machine at every tap; under-sink carbon filtration alone, a simpler single-unit purchase and never a membrane system; and the faucet add-on framing, reverse osmosis carried as lines inside a faucet project. The dedicated-faucet line and the old-unit removal line price on the breakdown guide where a frame prints them, apart from the form rows here. Each form row above prices a reverse osmosis system as its own ticket only.
Reading a by-system quote, by frame
- Form named beside every figure
- Unit row read apart from the installed row
Frequently asked questions
What does a countertop reverse osmosis unit cost, as reported?
Frame A prints countertop, point-of-use at $200 to $700. Frame B prints a countertop row at $200 to $450 installed. The readings stand apart by frame, beside under-sink rows at $200 to $800 in Frame A and $300 to $950 installed in Frame B, never blended.
What do under-sink units with a tank and tankless units print at, as reported?
Frame B prints under-sink with tank at $300 to $700 installed, on a unit row at $150 to $350, and tankless at $450 to $950 installed, on a unit row at $300 to $600. Frame A prints under-sink at $200 to $800 and tankless at $250 to $900, with unit and installed rows not split by form.
What does a whole-house reverse osmosis system print at, as reported?
Frame A prints whole-house at $1,000 to $4,800. Frame B prints whole-house installed at $4,800 to $8,000, by unit size from $4,800 to $7,000 at 500 gallons per day to $5,800 to $8,000 at 1,500 gallons per day. That divergence is a frame difference, never averaged here.
What do the average, brand, and filter rows print at, as reported?
Frame A prints an average installation of $2,200 and annual maintenance at $175 to $600. Frame B prints unit prices at $150 to $600 on average, a Culligan system at $1,050 to $1,700 installed, and new filters at $20 to $100, each row priced apart inside its own frame.
Is a form row the same purchase as a water softener, whole-house filtration, or a faucet add-on?
No. Each row here prices one reverse osmosis form as its own ticket. Water softeners, whole-house filtration, under-sink carbon filtration alone, and the faucet add-on framing sit in their own lanes, named apart on every page here, with the whole-house form read only as this cluster's comparator row.