Do you even need one?
If your only concern is the water you drink and cook with, you probably don't.
A filter at the kitchen tap, a reverse osmosis system or a certified under-sink unit, is cheaper, easier to install, and actually more thorough, because the water moves slowly through a dense filter instead of rushing through a big system feeding the whole house.
A whole-house system earns its cost when your concern goes beyond the drinking tap: chlorine you absorb in a hot shower, sediment that wears on your water heater, hard-water scale, or PFAS you want reduced everywhere. If two or more of those apply, it starts to make sense.
The two kinds
Most whole-house filters fall into one of two groups:
1. Chlorine, sediment, and scale systems.
This is what most whole-house filters are, carbon and KDF media that make water gentler on skin, hair, plumbing, and appliances. What they don't do is reduce PFAS.
2. Whole-house PFAS systems.
Far less common, these use media specifically tested to reduce PFAS at every tap, including the shower.
Two honest caveats on the PFAS systems
First, they're independently tested (by SGS) rather than NSF-certified, no whole-house PFAS system currently carries NSF certification, so tested is the best available in this format, though certified PFAS reduction is available at the tap.
Second, they work best paired with a tap filter. A whole-house system passes water quickly to feed the whole home, which makes PFAS reduction less complete than a slow single tap. The honest ideal is two layers: whole-house for coverage everywhere, plus a certified filter at the kitchen tap for the water you actually drink.
One more thing these systems don't do: soften water. They can condition it to prevent scale, but genuinely soft water needs a dedicated softener.
