Under-Sink and Reverse Osmosis Water Filters in Phoenix

Two kinds of under-sink filter

A cartridge filter is one or two canisters under the sink. Water passes through carbon, which takes out chlorine taste and smell and some other things, and comes out at a small faucet on the sink deck. It's quick to install and the filters are easy to change.

A reverse osmosis system does more. It pushes water through a membrane that strips out most of the dissolved minerals and salts, which is what makes Phoenix water taste the way it does. It stores the water in a small tank under the sink, so the tap has pressure. It also sends some water down the drain as it works. An RO system is the one to pick if you want the water to taste like bottled water. A cartridge filter is enough if you mostly want the chlorine gone.

What an install involves

Both kinds tap into the cold water line under the sink with a small valve, so the main supply isn't touched. Both need a faucet on the sink deck. If the sink has a spare hole, often where a sprayer or soap dispenser was, the faucet goes there. If not, a hole gets drilled in the counter or sink, which we can do in stainless steel and most stone.

An RO system also needs a drain connection. A fitting goes on the sink drain pipe for the reject water. If the sink has a disposal, the drain connection goes on the pipe above it. And the storage tank takes up room, so a cramped sink base with a disposal and a pull-down faucet weight already in it needs a look before anything is ordered.

A fridge ice maker can run off the same filter, with a line through the cabinets. That's a common add-on, and it means the ice stops tasting like tap water too.

Filter changes

Carbon filters last six months to a year. The RO membrane lasts two to three years, longer if the pre-filters are changed on time, since they protect it. Phoenix water is hard, and scale shortens the life of everything, so the shorter end of those ranges is a safer bet here.

When the water slows to a trickle at the filter tap, or the taste comes back, the filters are overdue. We change filters on systems we installed and on most others, and we can set a schedule so it doesn't get forgotten. We'll tell you the filter model so you can buy them yourself if you'd rather.

What a filter doesn't do

An under-sink filter treats one tap. It does nothing for the scale on the shower door, the spots on the dishes, or the wear on your faucets and water heater. That's a whole-house hard water problem.

Problems we fix on this page

• Want a reverse osmosis system under the sink
• RO system leaking
• RO faucet dripping
• Want a whole-house filter
• Filter housing leaking
• Want water tested
• Want a whole-house water treatment system
• APEC RO system install
• iSpring RO leaking
• Costco RO system install
• RO tank not filling

How it starts

Send a photo of the sink from above, showing the holes, and one of the space under the sink with the doors open. Tell us whether you want just drinking water or the fridge too. You'll have a fixed price before anyone shows up. We can install a system you've already bought. Levi does the work himself.