Whole-House vs Under-Sink Filtration: Which Do You Actually Need?
Every homeowner shopping for cleaner water eventually asks the same question: do I really need a whole-house system, or is a good under-sink filter enough? The honest answer depends on what's in your water — and what you care about protecting.
Published January 27, 2026 · Shield Water Solutions
What each system actually does
An under-sink reverse osmosis (RO) system treats one faucet — usually the kitchen. It removes almost everything, including minerals, but at 1–3 gallons per minute and with 3–4 gallons of wastewater per treated gallon.
A whole-house (point-of-entry) system treats water as it enters your home, protecting every fixture. Depending on the stack, it targets sediment, chlorine, chloramines, PFAS, hardness, iron, and more.
When under-sink is enough
You rent, or you're staying under two years. Your only concern is drinking water. Your municipal water is already soft and low in disinfection byproducts. You're fine replacing membranes every 6–12 months.
When whole-house wins
You have hard water (most of Central Florida). You've noticed skin, hair, or laundry issues. You want protected showers and ice. You want appliances to last their designed lifetime. You're on well water. You've had PFAS or disinfection-byproduct concerns.
Many homeowners end up with both: a whole-house stack for protection, plus a small RO polish at the kitchen sink for drinking and cooking. That combination is the gold standard.
Ready for cleaner water?
Get a fixed, no-pressure quote for your Central Florida home in under 2 minutes.
Get my free quote →