Cat Water Fountain Stainless Steel: 108oz/3.2L Cat Fountain for Drinking - Pet Water Fountain Inside - Automatic Dog Watering Dispenser Bowl - Pet Feeding & Watering Supplies - Water Level Window

I use this one https://www.amazon.com/dp/B0C9JPHRD5?ref_=ppx_hzsearch_conn_dt_b_fed_asin_title_5&th=1 which has less of an exposed reservoir than the one that you’re using which should reduce the amount of splash that you are seeing. Mine sits on a rubber mat. I don’t use the filters on the indoor fountain, they just seem to add to the bacteria challenge. The water in cat fountains needs to be replaced regularly in any event.