Poly-Flo's most popular biological filtration media. It is available in 1-1/4" and 2" thicknesses. The 2" material is used exclusively in virtually all US manufactured pond skimmers and waterfall units. The open character of this filter media allows for high volumes of water to pass through without cogging while providing optimal surface area to facilitate bacterial colonization.
Recommended for the Poly-Flo Biological Filter Media