Why it matters
The Shower Replacement Filter, in short.
Old cartridge = back to chlorine.
The details
Specifications
Specifications reflect the manufacturer (Sentry H2O). See our Science page for published independent lab reports and testing gaps. Sentry H2O reports its systems are tested to NSF standards; certification documents are being finalized, so we do not call them NSF certified.
Sentry H2O · Subscribe & Save
Sentry H2O Shower Replacement Filter — subscribe & save 15%.
Sentry H2O systems are built to last years — the filter change is what keeps them performing like day one. Subscribe and we ship the exact replacement on schedule, with a reminder before you run low.
Choose Subscribe & save 15% above to lock in your schedule — skip or cancel anytime.
Subscribe & Save arrives with checkout on this preview build.
Straight answers
Common questions
Is the Sentry H2O Shower Replacement Filter right for my home? +
Sentry H2O Shower Filter owners. Not sure? Our 60-second quiz confirms fit in a minute.
How often do filters need replacing? +
Every ~12 months (~6 months at 2+ showers a day). Subscribe to auto-ship and we'll send the exact refill on schedule with a reminder.
What if it is not right for me? +
Every refill is backed by a 30-day money-back guarantee. Filters and filter media are consumables.
What is catalytic-carbon filtration, and how is it different from reverse osmosis? +
Catalytic-carbon filtration uses specially processed activated carbon that reacts with and breaks down contaminants as water passes through multiple stages. Unlike reverse osmosis, our Sentry H2O systems don't strip the water of everything -- they target the bad stuff while leaving naturally occurring beneficial minerals in place. You get cleaner, better-tasting water without wasting a drop or plugging anything into the wall.
Does the system need electricity or produce wastewater? +
No electricity, no drain connection, and no wastewater. Reverse osmosis systems can reject 3 to 5 gallons for every gallon they make; our Sentry H2O systems reject none and run on normal household water pressure. That means no extra drain line, no outlet, and nothing to plug in.
Does it change the taste or smell of the water? +
Yes -- for the better. Chlorine and chloramine drive most of that tap-water taste and smell, and the ToxyGuard stage is built to reduce both. The AlkaGuard stage then adds back trace minerals for a cleaner, rounder flavor, without the flat aftertaste reverse osmosis can leave behind.
What about chlorine and chloramine from city water? +
Both are specifically targeted by the ToxyGuard stage in every Sentry H2O system. Chloramine is notoriously hard to remove with standard carbon, which is exactly why we use catalytic carbon -- its enhanced reactivity breaks chloramine down more effectively, so your water smells and tastes clean straight from the tap.
Real customers, real water
What owners actually say
Verified Sentry H2O reviews, independently collected by Judge.me.
Verified reviews of Sentry H2O systems, independently collected by Judge.me.
Reviews independently collected & verified by
Know your water
Know what is in your water before you choose a system.
Check the public data, test your tap, then match your home to the right Sentry H2O system.
Read your local water report
Your area's annual Consumer Confidence Report (CCR) lists what has been detected in your municipal tap water.
Salt Lake City? See what's really in your water →Check the EWG Tap Water Database
Enter your zip code for a plain-language breakdown of the contaminants found in your local supply.
Open the EWG database →Test your tap with an at-home kit
A mail-in lab kit such as Tap Score by SimpleLab tells you exactly what is in your own water.
Get a Tap Score kit (SimpleLab) →Want help matching the result to a Sentry H2O system?