15 PPI Aquarium Filter Sponge Open Cell Foam Sheet Bio Sponge Filter Media Pad HMF Fish Tank Sump Divider Cut-to-Size Foam

Note: The biochemical cotton will be vacuum packed and compressed when it is packaged and shipped. If you find that the biochemical cotton is small, deformed or not thick enough after receiving the goods, put the biochemical cotton flat for 1-2 days, the biochemical cotton will be Restore to the original state, vacuum compression will not have any effect on the filtration performance of the biochemical cotton, please rest assured to use it after the biochemical cotton is restored to its original state.PPI: 15 black fine

The open cell sponge has a much larger inner surface area for filtration capacity.

This filter pad can be cut to fit and used as a pre-filter for any aquarium or pond filter, sump, wet/dry, canister, power filter etc. or your HMF DIY project.

The reticulated structure also provides better flow rate of water and less chance of clog.

The size of pores is measure in pores per inch (PPI). The sponge with higher PPI has more pores in it. More pores means larger filtration capacity but with less water flow through rate and needs to be cleaned more often. It is recommended to use combination of sponge with difference PPI to get the best result.