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Home Water Filter Guide

What flow rate does your home need?

Size a whole-house filter by gallons per minute, not by tank size. Tell us your bathrooms and water source — we'll show the systems rated for your peak demand.

Rated service flow by systemGallons per minute, manufacturer ratings. Size for your peak demand, not the average.
E-1000 15 GPM Heavy Metal 3-Stage 15 GPM PSE2000 15 GPM WGB32B 15 GPM WGB32B-KDS 15 GPM CB3 Big Blue 12 GPM CF4 12 GPM Chlorine+ Fluoride 10 GPM CF1 9 GPM LCR 8 GPM Rhino EQ-1000 7 GPM HealthShield 6 GPM

Most homes need 8–12 GPM at peak (showers + dishwasher + laundry). Use the flow-rate sizer to match your bathrooms.

How the sizing works

We estimate peak demand as 3 GPM base (kitchen + laundry) plus2.5 GPM per bathroom. A 2-bathroom home needs about 8 GPM at peak — two showers running while the dishwasher fills. Systems are matched at or above that number, then filtered by your water source and budget.

Undersized systems don't just slow your shower — low contact time means worse filtration. When in doubt, size up one step: the price difference is small compared to a re-install.

Once you know your flow rate, check the 5-year cost calculator — the cheapest system to buy is rarely the cheapest to own. For the full picture, read how to choose a whole-house water filter.