Best Value Under $150 · 1 of 5
A. O. Smith Under Sink Water Filter System

- 2-stage Claryum filtration
- Reduces 78 contaminants
- Certified to NSF/ANSI 42, 43, 401
Our take
The best-rounded system under $150.
Why it made the shortlist
The AO Smith AO-US-200 is a 2-stage Claryum system with a dedicated drinking faucet and a tee that connects to a 3/8 inch cold line. It reduces up to 99 percent of 78 contaminants, including lead, PFAS and chlorine, while leaving minerals, and the full system is certified to NSF/ANSI 42, 43 and 401.
At about $111 it undercuts the EcoPure by $11 and gives a wider contaminant list. The CuZn UC-200 lasts longer, and this one is the better all-around system for the money.
Cabin owners, van builders and families who want a separate tap for drinking water will like it. The system suits a sink with room for an extra faucet.
What works
- Dedicated drinking faucet included
- Reduces 78 listed contaminants
- Leaves essential minerals
- Full-system NSF certification
Watch out for
- Needs a hole for the extra faucet
- Cold water only
- The catch
- Replacement filters are a recurring cost.






