Safety shutoff pellets
"I ordered these along with a cartridge replacement pack. While servicing our filter system, I noticed the installed safety shutoff pellet had apparently "dissolved" - there was nothing left. They swell when wet and turn off the master valve to the R/O filter system. It is important to me to have as much "flood" protection as possible (we even turn off our water main while we are gone). There are several potential leak points with our R/O filter system, and I want our cupboard protected from moisture. Luckily, we haven't had ANY leaks from our filter system, faucets, or disposer. These pellets give me peace of mind - however, they are expensive."