Circulating Sterilizing Cat Water Bowl

Problem

One of our cats likes to play with the water in their water bowl, inevitably splashing most of it onto the floor and leaving bits of litter and food in it.

Solution

Build a larger bowl that filters and sterilizes the water, with an absorption mat around it for spillage.

I started with a large pyrex baking dish, and added an aquarium pump to circulate the water. It was very noisy, so I put a glass pane from an oven light under the water flow. Over time, cat hair trapped in the aquarium filter would find its way around the pump's rotor, stopping it, so I removed the filter from the pump and put a fish scoop under the water flow instead (it catches the big stuff, and the pump doesn't get clogged anymore).

Completed

I added an ultraviolet light to the bowl, which seems to keep it sterilized. The green bowl holds a lot more water than the other one, so we're not refilling it as often. We took the filter out of the bowl and the pump, because it was getting clogged too easily.

Old design: