I ordered filters, but I also want to tell you about the drinking bowl. This is the best purchase for my ponytails. Now they always have clean water.
In the photo filter after two months of use.
This is the kind of water we have.
Cats got used to drinking water in a couple of hours, they are not afraid, they even came up for kittens (from a month they were able to get up and reach the water).
Moderately noisy, not annoying.