Turn off the cold-water valve under your sink. Then open the faucet to drain any leftover water—this saves you a wet surprise later. Now, breathe. You’re already halfway there.
Next, attach the saddle valve to the cold-water pipe. Tighten it gently until it bites into the pipe, then open it just enough to see a drip. Don’t over-tighten—we’re not wrestling a bear here. This little valve is your new best friend, letting the RO unit sip water without stealing from the main line.
