Pentair OmniFilter CB3
A NSF-certified under-sink filter that is certified to reduce 5 contaminants, including lead.
You want strong contaminant reduction at the kitchen tap without a countertop unit, and are comfortable with a simple under-cabinet install.
Certified to reduce Lead — the contaminants that matter most for health.
Like most carbon filters, it does not remove fluoride — only reverse osmosis does that.
What is under-sink filter? A carbon-based cartridge (or set of stages) plumbed under your kitchen sink that filters the cold drinking-water line. Compare all filter types →
What it costs to own
| Upfront price | — |
| Replacement filter (N/A) | — |
| Estimated yearly cost (filters, ~1.5×/yr) | — |
| True cost per gallon | — |
Cost per gallon and yearly cost are our estimates from the rated capacity and the Amazon price. We show them only when we read the price from Amazon in the last 24 hours. The filter only works if you replace it on schedule.
What it's certified to remove
Certification is per-contaminant: the Pentair OmniFilter CB3 is credited only for the contaminants listed here, verified by NSF. It does not imply removal of anything not listed.
✓ Verify this certification on the official NSF listing →
Full specifications
| Certified by | NSF |
| NSF/ANSI standards | 42 — reduces taste, odor, and chlorine (aesthetic standard) · 53 — certified for health contaminants such as lead, VOCs, and cysts |
| Filter type | Under-sink filter |
| Rated capacity | 400 gallons |
| Flow rate | .5 gpm |
| Replacement element | N/A |
| Installation | Mounts under the sink; connects to the cold line. Basic DIY. |
Frequently asked
Is the Pentair OmniFilter CB3 NSF certified?
Yes — the Pentair OmniFilter CB3 is listed in the NSF certified-product database under NSF/ANSI standards 42, 53. That means an independent body verified its claims (not just "tested to" a standard).
Does the Pentair OmniFilter CB3 remove lead?
Yes. It is certified to reduce Lead, plus 4 other contaminants. Certification is per-contaminant, so it is only credited for what is on its listed claim set.
What does the Pentair OmniFilter CB3 remove?
It is certified to reduce 5 contaminants: Chlorine / chloramine, Cryptosporidium, Giardia, Lead, Mercury.
How often do you replace the under-sink filter?
A under-sink filter like this is typically replaced about 2 time a year (replacement element N/A). Replace on schedule — a spent cartridge stops reducing contaminants.
Compare similar under-sink filters
Amazon prices as of October 20, 2026 at 2:01 PM ET; check Amazon for the current price.
Source: NSF public certification listing. Specs and certified claims are from the official listing; cost figures are our estimates. Some links are affiliate links — see our disclosure.