Reticulated polyurethane foam is a net-like, porous foam that is extremely versatile. It is also known as "Open Cell" since typically 95-98% of the cells are open. This open cell construction is extremely effective in many applications including water filtration.
Open cell foam porosity is designated in "Pores Per Inch" (PPI). The lower the PPI, the greater the porosity. For example, 10 PPI foam is very see through and a versatile barrier. It is very effective for example, when used inside overflows to keep smaller aquatic creatures from being sucked down into the filter.
Open cell reticulated foam is the most effective biofiltration media available. Tenecor AquaFoam has the added advantage of being extra thick, saving you time and money.
Learn more here why AquaFoam is the superior alternative to filter socks.
NOTE: This is 4 Inch Thick AquaFoam. Thick foam like this is hard to find and works much better than stacked sheets.