A reverse osmosis system isn’t a one-size-fits-all box. The right setup depends on how much water your household drinks, how much pressure you have, and where it needs to feed. Here’s how to get it right the first time.
The short answer: Most homes need a standard under-sink RO system sized to daily drinking and cooking. Sizing comes down to your production rate in gallons per day, your storage tank, and your water pressure. A clean under-sink install adds a dedicated faucet and can also feed a fridge or ice maker.
Sizing: it’s about how much you draw at once
RO systems are rated in gallons per day, but that number can mislead you. Because the system stores clean water in a tank, what really matters is whether the tank keeps up with how much you pull at peak times. A couple drinking and cooking has very different needs than a big family filling water bottles every morning. We match the production rate and tank size to your actual routine, so you’re never waiting on the tank.
The under-sink install, step by step
- The unit mounts in the cabinet. Filters and membrane housing tuck to one side.
- The storage tank sits nearby. It holds the clean water ready to pour.
- A dedicated faucet goes in at the sink. Separate from your main tap, just for RO water.
- A drain connection handles the reject water. Done cleanly so it’s quiet and sanitary.
- Optional lines feed the fridge or ice maker. So your ice and cold water are RO too.
Pressure: the detail that makes or breaks it
The membrane needs pressure to work. If your home runs on the low side, a weak system trickles and the tank never fills. That’s why we measure pressure during the free test. If it’s low, a permeate pump or booster keeps production strong. Get this right and you’ll never think about it again.
Orange County note: our water is hard, so pairing RO for drinking with a softener for the whole house is a common, smart combination. The softener protects your plumbing and the RO polishes your drinking water. See the signs you have hard water if you’re not sure whether hardness is an issue for you.
Vertex IsoTwist reverse osmosis
A five-stage under-sink reverse osmosis system that gives you bottled-quality water at the kitchen tap, with an optional remineralization stage that puts good minerals back for taste.
LC Reverse Osmosis
A commercial-grade reverse osmosis platform built for restaurants, cafes, and businesses that need high-purity water at volume.
Keep learning about your water. Start with how reverse osmosis actually works Then whether reverse osmosis water is healthy Then the best water filter for drinking.
Home reverse osmosis: sizing and install questions
What size reverse osmosis system do I need for my home?
Most homes are served well by a standard under-sink system rated for daily household drinking and cooking. If you have a large family or want RO feeding a fridge and a pot filler, we’ll size up the production rate and tank. The right size depends on your water pressure and how much you draw at once.
Where does an under-sink reverse osmosis system get installed?
Under the kitchen sink, in most cases. The unit and storage tank tuck into the cabinet, and a dedicated faucet mounts at the sink. It can also feed an ice maker or a separate drinking tap with the right plumbing.
Can I install a reverse osmosis system myself?
Some homeowners do, but the details matter: drain connection, pressure, and a clean sanitary install that won’t leak or grow buildup. A professional install also means the system is sized to your actual water and backed by service.
Does a reverse osmosis system need a lot of water pressure?
It needs adequate pressure to push water through the membrane. If your home runs low, a permeate pump or booster keeps production strong. We measure pressure during the test so the system is matched to your home.
Get sized right with a free in-home test
We measure your pressure and your water before we spec a thing, so your reverse osmosis system fits your home instead of a generic assumption.
Book your free in-home water test
Prefer to talk it through first? Call us at (949) 569-5736. Family owned in Irvine since 1972, licensed and insured, California CSLB C-55 #1022717, serving all of Orange County.