Whole-house system vs Under-sink filter
They solve different problems. A whole-house system protects every tap and shower from chlorine and sediment but rarely carries health-contaminant certification. An under-sink filter is certified for drinking-water contaminants like lead and PFAS. Many homes use both: whole-house for the home, under-sink for drinking water.
| Whole-house system | Under-sink filter | |
|---|---|---|
| Best for | You want every tap and shower treated — best for chlorine, sediment, and taste across the whole home. | You want strong contaminant reduction at the kitchen tap without a countertop unit, and are comfortable with a simple under-cabinet install. |
| Typical cost per gallon | ~1¢ | ~6¢ |
| Removes fluoride / arsenic | No | No |
| Most contaminants certified | up to 3 | up to 14 |
| Installation | Point-of-entry install on the main line. Usually a plumber. | Mounts under the sink; connects to the cold line. Basic DIY. |
| Filter changes / year | ~1 | ~1.5 |
| Certified models we track | 154 | 764 |
Still not sure? The right choice depends on what's actually in your water. Look up your ZIP to see your contaminants, then pick whichever type is certified to remove them at the lowest cost per gallon.
Frequently asked
Is whole-house system or under-sink filter better for lead?
Both can be certified for lead — what matters is the specific model's certification, not the category. Look for NSF/ANSI 53 lead certification on the exact model. We list the certified claim for every filter.
Which is cheaper over time?
Compare cost per gallon, not sticker price. Here, Whole-house system is typically cheaper per gallon (~1¢ vs ~6¢), because the running cost of replacement cartridges usually outweighs the upfront price.