Gross! Also… a large portion of the granules get flushed down the rest room. I haven’t researched those particularly… but I can’t think about that it's great for the plumbing. The granules appear to be plastic. Maybe they biodegrade? Idk.. not my fav. We are hunting in to other systems. https://petskyonline-onlinestrore.blogspot.com/2025/07/petkit-purobot-ultra-premier-auto.html