Originally posted by Tiger15
Craft shops like JoAnne Fabric in my area sell stiff Polyester Batting in big rolls cut by yard that are no different from pet shop padding. They come in different thickness from 1/4 to 1/2 inch and I always buy the thinnest 1/4 inch batting. For mechanical filtration, there is no need for great thickness because once the surface is clogged, the rest of the thickness is useless. I just trash it because it's not worth to clean it for less than a nickel per piece. For my Whisper, I wrap the pad over the bioframe and clip it. For my Penquen, I clamp the pad inside the filter box I purchased separately.