TL;DR: Use a leak sensor without an alarm to detect when water in a dog bowl drops below a certain level.
Back in 2018, I installed an auto-refilling water bowl for our dog, mounting it on the wall in our laundry room. It worked well, but there was something disconcerting about having a water line under pressure, so when we moved to our new home, we didn’t take the auto-refilling bowl with us.
Recently, after we had our second child, I found myself forgetting to fill our dog’s water bowl to his liking. As part of my never-ending quest to automate any need for my ability to remember anything, I looked into options for an automated reminder.
I happened upon a Reddit post showing a setup using an Aqara leak sensor with wires attached to the leads going into the bowl. From my research at the time, this was the only leak sensor I could find that didn’t have a built-in alarm, which is important when being wet is the default state!
At first, I tried to just install the sensor right inside the bowl, but I couldn’t find a way to keep it attached reliably and it got pretty gross with all of the dog slobber.
I ended up attaching it to the wall behind our dog bowls using a velcro Command strip and running a pair of twisted wires down to the bowl.
After about four months, the battery has depleted by about 25%. Not bad! But most importantly, our dog doesn’t have to wait long for me to fill his bowl any more.