Quick Take
The CuZn Bath Ball is the minimalist's bath filter - no frills, no complexity, just basic chlorine reduction at rock-bottom pricing. It will not match the Kinder Filter's comprehensive approach, but at under $30 with year-long life, it is worth trying.
Overall Score: 7.6/10 - Best budget option
What We Evaluated
Using R3's bath filter methodology v1.0.0.
Safety Analysis - Score: 7.8/10
Chlorine Removal
CuZn uses patented bacteriostatic KDF media (copper-zinc alloy) for chlorine reduction. The brand claims 90%+ removal, which aligns with independent KDF performance data. Not as comprehensive as multi-stage filters.
Heavy Metals
KDF naturally targets lead, mercury, and copper. The Bath Ball's smaller media quantity means less contact time than larger filters.
Performance - Score: 7.4/10
Filter Life: 12+ Months
Ironically, the budget option has the longest claimed filter life. CuZn attributes this to their patented micro-porous technology. Real-world reports suggest 8-10 months is more realistic with regular use.
Filtration Technology
Single-stage KDF - effective but limited. No vitamin C, no carbon, no multi-stage treatment.
Design Consideration
The ball design is unconventional - it sits in the tub while filling. Water flows around it rather than through it, which may reduce filtration efficiency compared to inline filters.
Value - Score: 8.8/10
At $29.95 with 12-month life and no replacements needed, first-year cost is just $29.95. Second-year is another $29.95. This is unmatched value in the category.
Usability - Score: 7.5/10
No installation required - just drop it in the tub while filling. This is both a pro (no faucet compatibility issues) and con (water flows around it, not through it). Some users find the floating ball design awkward.
Who It Is Best For
- Budget-first families seeking entry-level filtration
- Renters who want zero installation commitment
- Those testing the category before investing in premium options
Who Should Skip This
- Eczema or sensitive skin needing maximum chlorine removal
- Those wanting inline filtration where all water passes through filter
- Design-conscious buyers (the ball looks utilitarian)
The Bottom Line
The CuZn Bath Ball will not win any awards, but at under $30 for a year of basic chlorine reduction, it is worth trying if you are curious about bath filtration. Upgrade to the Kinder Filter if you need comprehensive protection.
Final Score: 7.6/10 - Best for budget testing
