Reverse Osmosis System Install: DIY Guide
Under-sink RO systems are designed as a DIY kit — tubing connects with push-fit fittings, no soldering required.
DIY-Friendly
RO systems are explicitly designed for homeowner installation with push-fit tubing connections. The most technical step is drilling a hole for the faucet, which most kits include a template for.
Skill Level
Beginner
Time Required
1–2 hours
Physical Demands
Kneeling under the sink — low overall
Step-by-Step
- 1
Shut off the cold water supply under the sink
Test by opening the tap to confirm water is off.
- 2
Install the faucet or drill a hole if needed
Most kitchen sinks have a pre-drilled hole for a soap dispenser or sprayer you can repurpose; otherwise use the included drilling template.
- 3
Install the feed water adapter
This taps into your cold water supply line to feed the RO system.
- 4
Mount the filter housings
Secure them to the cabinet wall in an accessible spot for future filter changes.
- 5
Connect the drain saddle
Clamps onto your sink drain pipe to route the system's wastewater.
- 6
Connect tubing and flush the system
Run the system for the manufacturer's specified flush time before first use to clear carbon fines.
Tools & Materials
Tools
- Drill (if drilling a new faucet hole)You likely own
- Adjustable wrenchYou likely own
- Tubing cutter (usually included in kit)You likely own
Materials
- RO system kit
- Feed water adapter
- Drain saddle
Permits
Permit requirements for this project vary by state and municipality. Select your state above for specific guidance, or check with your local building department before starting work.
When to Call a Pro Instead
- • Your cold water shutoff valve is stuck or leaking — see the faucet/toilet swap guide for that situation first
Safety Warnings
FAQ
Can I install a reverse osmosis system myself?
Yes — RO systems are specifically designed as DIY kits with push-fit tubing, no soldering or specialized tools required beyond a drill if you need a new faucet hole.
You might also find these helpful