Open 7 days, 8am to 8pm. Hablamos Español. Call or text (925) 421-5904Lic. #870501

Holiday Offer: $480 off any whole-house water system, plus a free year of salt deliveryEnds December 24
Drinking Water

Is Reverse Osmosis Worth It?

How an under-sink reverse osmosis system works, what it costs you in upkeep and water, and who gets the most out of one.

Clean water splashing into a glass

If you're tired of hauling cases of bottled water home, reverse osmosis (RO) is worth a look. It's the same basic technology many bottled water companies use, sized to fit under your kitchen sink.

How it works

An RO system pushes your water through a few stages, one after another:

  1. A sediment pre-filter catches dirt, sand and rust.
  2. A carbon pre-filter protects the membrane and improves the taste.
  3. The RO membrane, a very fine membrane, does most of the work.
  4. A post-filter polishes the taste before the water reaches its own faucet.

Some systems add one more stage that puts minerals like calcium and magnesium back in, which gives the water a smoother taste.

What you get

Good water for drinking, coffee, tea, cooking, ice and baby formula, from a faucet at your own sink. No more buying, storing or recycling plastic bottles. And you can see the difference in numbers: we take a TDS reading before and after so you can compare.

Before you buy

The filters need changing. The pre- and post-filters usually go every 12 months, and the membrane every few years.

Some water goes down the drain. RO uses extra water to rinse the membrane, though modern systems waste much less than older ones.

It's for drinking water. RO usually goes in at one sink. If you also have hard water or chlorine in the shower, that's a job for a whole-home system. Many of our customers have both: a whole-home system for showers, laundry and appliances, and RO at the kitchen sink for drinking.

Is it worth it?

For most families who drink a lot of water, cook at home or buy bottled water now, we think so. A free water test will show your current TDS level and help you decide.

Find out what's in your water. Free.

Our free in-home water test takes about 30 minutes, with no obligation. We'll explain your results and show you your options.

← Back to all articles
Free In-Home Water Test

Pick a day and time

This is a request. We'll call or text to confirm your time. See what the test includes