About CuZn
CuZn is a long-running name in under-sink water filtration, built around a three-stage design: a sediment pre-filter, catalytic coconut shell carbon, and KDF-55 media, a copper-zinc alloy that gives the brand its name and is engineered to reduce chlorine, chloramines, and dissolved heavy metals while resisting microbial growth in the housing over long service intervals. The flagship UC-200 line is rated for five years or 50,000 gallons between cartridge changes, roughly five times the service life of a typical carbon-block under-sink filter, and connects inline to the existing cold-water supply rather than routing to a separate dedicated faucet.
The brand operates today under HALE, part of Waslix, a Pittsburgh, Pennsylvania water-filtration manufacturer that continues to sell and support CuZn-designed under-sink and point-of-use systems alongside its own product lines. The UC-200's long-life, low-maintenance approach has drawn independent coverage across water-filtration review outlets, and in our own testing its inline design was the only system in its category that preserved full faucet flow rate rather than throttling water through a smaller dedicated tap.
Brand website: haleflow.com
What CuZn makes
CuZn's range runs wider than the products we review. The lines we know best from our own testing are marked with a star:
UC-200 Series
under-counter long-life filtration, 5-year / 50,000-gallon cartridge combining KDF-55, coconut shell carbon, and sediment media — featured on DIYRated
UC-100 Series
under-counter filtration systems
UC-2K / UC-3K Series
under-counter water filtration systems
WHBB3 whole-house systems
combined chloramine, hardness, and fluoride reduction on the main water line
KR-101 point-of-use filters
wide-spectrum chlorine adsorption for a single tap
Why we recognized CuZn
The DIYRated Top Brand recognition isn't paid for and can't be applied for. We award it to the brands whose products consistently stand out in our hands-on category reviews. CuZn earned it on the strength of the products below, evaluated the same way every product on this site is: bought, put to work on real jobs, and judged on merit.
CuZn products we rated highly
CuZn UC-200 Under Counter Water Filter System with 50,000 Gallon Capacity
Rated for five years or 50,000 gallons between cartridge changes, the longest service life in our roundup by a factor of five, so most owners replace the cartridge once and never think about it again. The three-stage stack (sediment, KDF-55, and coconut shell carbon) is NSF/ANSI 42 and 372 certified and targets chlorine, chloramines, lead, and mercury, with bacteriostatic KDF-55 that resists microbial growth in the housing over that long service interval. It installs inline on the existing cold-water line and holds full faucet flow at roughly 2 GPM, and its stainless steel housing is made in the USA.
Read the 7 Best Water Filters of 2026 guide →What earned CuZn the recognition
- Three-stage media (sediment, KDF-55, and coconut shell carbon) rated NSF/ANSI 42 and 372, with bacteriostatic KDF-55 that actively resists microbial growth in the housing over long service intervals.
- Five-year, 50,000-gallon cartridge life, the longest in our under-sink water filter roundup by a factor of five, so most owners never revisit the filter after the initial install.
- Inline installation preserves full faucet flow at roughly 2 GPM, rather than routing through a smaller dedicated tap the way most competing under-sink systems do.
- Stainless steel housing made in the USA, built to hold up in a damp under-sink cabinet better than the plastic housings common in this category.
- Independently reviewed across multiple water-filtration outlets, and continues to be sold and supported today under HALE (Waslix).