The AquaEl Hypermax 30ppi Finish Sponge is a high-performance filtration media designed for the final stage of aquarium filtration. With a dense 30 pores per inch (PPI) structure, this sponge provides superior fine mechanical filtration, effectively removing small particulate matter, while also offering an excellent substrate for beneficial bacteria to thrive. The result is crystal-clear water and a healthy, balanced aquatic environment.