What filters does it work with?+
Any filter in a housing with a transparent or translucent window the sensor can see through — most whole-house and under-sink water filters qualify. The sensor reads the cartridge's color through that window.
How does it know the filter is dirty?+
It shines white LEDs on the filter and measures the reflected color with an optical sensor. As the cartridge darkens with impurities, the measured color shifts; the device maps that to a dirty / not-dirty status.
How long do the batteries last?+
Over two years typically. The sensor sleeps almost all the time and wakes only about once a day to take a reading, so it draws very little power from its 4 AA batteries.
Does it need a hub?+
No. It connects directly to your home Wi-Fi after a one-time setup in the app. No separate hub or bridge required.
Can I monitor more than one property?+
Yes. Add as many sensors as you like and name them by location — home, office, vacation house. You'll see the status of every filter in one app and get alerts wherever you are.
What's the return policy?+
A 30-day return window from delivery. Email orders@eyeonfilter.com for a return and full refund. The sensor also carries a one-year warranty against defects.