The Honest Shower-Filter Library

Learn — science, not marketing

We publish the research, comparisons and how-to guides we wish every shower-filter buyer had before purchasing. No staged magic, no fake soft-water claims — just what the media actually removes.

Buying Guides →

Choose the right filter for your water, budget and fixture.

Water Science →

What is actually in shower water: chlorine, chloramine, hardness, TDS.

Filtration Technology →

KDF-55, activated carbon, vitamin C and how filtration media work.

Standards & Certifications →

What NSF/ANSI 177 really tests — and why it matters for shower filters.

Start here — the standard everything else references

Installation →

Step-by-step installs, cartridge swaps and tool-free fits.

Maintenance →

Keep flow strong, catch leaks early, extend cartridge life.

Comparisons →

Inline vs showerhead, KDF vs carbon, and other head-to-heads.