Phoenix & the Valley
If the problem is how it tastes, this is the machine.
A softener is not a filter. If you are unhappy with the water in the glass rather than the water on the shower door, softening was never going to fix it.
The difference in one line
A softener exchanges calcium and magnesium for sodium so that water stops depositing scale and starts lathering. Reverse osmosis pushes water through a membrane and takes out a broad range of dissolved material, which is what changes how it tastes. They solve different problems and plenty of homes here end up with both.
Why it comes up in Phoenix specifically
The city reported total dissolved solids of 464 to 716 ppm in 2025, against a non-enforceable EPA secondary guideline of 500. TDS is a large part of what people mean when they say water tastes “mineral” or “flat.” A softener does not reduce it. An RO system is aimed squarely at it.
What it costs to run
Membranes and pre-filters are consumables on a schedule, and RO sends some water to drain to produce treated water. Both are worth knowing before you buy rather than discovering later. We will put the filter interval and the expected annual consumable cost on the quote.
Typical prices
| Item | Typical range |
|---|---|
| Under-sink RO, standard install | $450–$900 |
| RO plumbed to fridge and ice maker | add $120–$250 |
| Annual filter set | $90–$180 |
Ranges, not quotes. The figure that matters is the written one you get after we have measured your water and seen the plumbing. We would rather give you a wide honest range now than a precise number we have to walk back on the day.
Questions
Does RO remove the sodium a softener adds?
Largely, yes — which is why softener-plus-RO is a common pairing for a household that wants soft water everywhere and low-sodium drinking water at one tap.
Where does it go?
Under the kitchen sink, with a dedicated small tap on the counter. It can also feed a fridge or ice maker, which is usually worth doing at the same time.
Do I need one if I have a softener?
Only if you care about taste or dissolved solids. A softener already handles scale and lather. If the drinking water is fine by you, do not buy a second box.