From time to time you may notice your Quick-Dry Earth Mat is not soaking up water as fast as when it first arrived. Diatomaceous Earth is a naturally occurring silica-based material, but in very wet / heavily trafficked areas the Earth Mat may become oversaturated. Don't worry, there’s a quick fix. Using the 400 grit (included in the box) gently sand the surface to remove the top layer. Alternatively, removing the Earth Mat from the bathroom occasionally to let it completely dry out works as well.